A/C woes

[chilort]

I've been trying to get the A/C in my '86 Daytona CS working for months now. I've been doing part of it myself and also let Firestone (FS) do part. Currently every single part of the A/C system has been replaced it it still won't cool.

What can I do to make an R134a system work in this car?

Long story short - FS replaced the evaporator. This got the system working until everything else decided to leak. Replaced consdenser, all lines, compressor, dryer, low pressure cut out, h-block. I also removed my old fan since it was squalling like it was about to fail and replaced it with two fans. One fan is setup as a pusher the other as a puller and they are offset to try to cover the most area.

What do you all do? Are their specific brands that work better. I have no idea what brand the evap. is. The compressor is a rebuild and the condenser is from O'Reilly auto parts.

I really need A/C. I live in Atlanta and it is really getting hot. And when it isn't really hot, it is sort of hot and humid because it keeps raining every day during this terrible drought we are having.

[MiniMopar]

Go buy a set of gauges and check the pressures in the system. You will save $$$ in the end, since you will be revisiting the A/C overy now and then on these cars. The gauges should come with instructions on what pressure to look for, but they are ballpark, depending on the overall performance of the system. You have to run higher-than-stock head pressures with R134a to get decent performance, so you can't really use the FSM as a guide.

I have had horrible luck with these compressors. i went through about 4 rebuilds before buying a new one. I was skeptical about the new one, but it seems to be holding up so far (about a month). I have also rebuilt them myself with some success, but for some reason the shaft seals always fail. I'm not sure why yet (the bearings are fine). These compressors are problematic overall and I don't imagine they live too long pumping R134a at R134a pressures, either (I use Duracool).

Anyway, what I look for when charging the system is the little window on the receiver/filter. Once you scrape the paint off, you want to see no bubbles going by when the compressor is running. This means that the H-valve is getting liquid refrigerant and should be performing at it's best. Then I look at the pressures at various RPMs to make sure they are OK.

I've had some interesting adventures with these A/C systems over the years and my dad and I came up with some tricks over the years that seem to help with sealing issues and efficiency.

[MiniMopar]

Sorry, went on a rant without answering your questions:

Are you sure the pusher fan is pushing and the puller fan is pulling? I'm just using a good-ol' stocker and it works great. The '86 shroud is nice and big, covering most of the area. The only issue is the little flapper-doors, if you have them, tend to disappear. This will hurt airflow when you are not moving.

The aftermarket condensers don't work as well as the OEM one, but even the OEM one isn't great. I used to be able to say that 100% of my OEM condensers failed after a few years, but for some reason my Daytona still has one and it works. You can recognize the OEM one by the square tubes and weird fins that seem to be shaved out of the tubing. The aftermarket ones look more conventional with rounded flat tubes and fins attached to them.

What are you seeing? Does the compressor run? Does the compressor discharge side get hot and the suction side get cold? Is your heater bypass valve working with you put the system in "recirc"? Does that recirc actuator move the damper (passenger side of the HVAC unit)?

[chilort]

Okay, thanks for the great responses. Sorry I'm a tad slow, but spent yesterday evening pulling the heater box out of the car .... never a fun job.

Even after several attempts to charge the system, FS was never able to get the R134a past the site glass in anything other than a milky consistency. They even tried changing out the h-block a second time.

Your advice on getting a set of gauges sounds good. Where do I get a set?

To answer some of your questions:
I am positive my puller is pulling. I placed the pusher in front of the condenser so it is much more difficult to check out, but it was moving air in the correct direction. Since I'm gonna have to take it all back apart again (more than likely) then I'll double check the pusher. It is a smaller fan. The puller was able to keep the engine in the correct temperature range without a problem. I simply added the small booster to try to help the A/C system.

I did put in a more conventional style condenser. The original was still in the car. As far as I know, it didn't leak at all. But since I was replacing everything, I figured I'd give it a shot too. What makes the the more conventional style less efficient?

The compressor, when it has sufficient pressure in the system, does run. The cold side gets cold the hot gets hot. As stated earlier, they've never been able to remove the milky consistency of the R134a even using a couple of methods to fill the system (even with my old compressor).

Let's see if I can make a long story short about how I got here.
Evap failed. FS replaced evap. System worked for a couple weeks, then everything under the hood (minus condenser) started leaking fluid. I replaced condenser, hoses, compressor (with 7.25oz of Ester oil), dryer, and fan. FS filled system and wasn't working well, said I needed to add a booster fan. I added a booster fan and a touch more R134a (I only have a low side gauge that came with the conversion kit). System cooled down to 60* on an 85* day. I was happy enough. Then the connection between one of the hoses and the condenser leaked. System quit. I tightened fitting and added R134a. System wouldn't cool down past 70* on an 85* day. Decided to add more R134a. While putting in more R134a (my low side gauge was still in the "blue" zone indicating okay) I heard a hissing. Turned off the car, located the hissing at the evap. I could move the evap and make the sound get louder or quieter. Threw can of R134a across the yard and gave up.

By the way, there's more stuff in there about FS, but in the end, I've called their complaint line and am requesting all of my money back. Guess we'll see.

Also, the heater core and the heater valve are new.

Today, after getting some more "real work" done, I'll break open the heater box and take a look.

[MiniMopar]

OK, well there could be a lot of things wrong. If I were to make a wild guess at what happened, they didn't pull a vacuum on it initially and there was moisture in the system...to much for the drier to handle (was the drier replaced?). When there is moisture in the system, it freezes at the H-valve and the pressure on the high side spikes WAY up and either blows a hose, seal, or eventually destroys the compressor. Another thing that happened to be once is a new drier failed (aftermarket crap) and all the little element bits got into the lines, clogged the H-valve and blew the seal. A bad H-valve could cause issues too, but less likely.

It could also be that you have two different types of oils in there, PAG vs Ester. I know they don't like each other. I would take the system apart, flush the coils and lines, replace the drier again, put one kind of oil in there, and pull a vacuum on it to see if it holds.

I got my gauges at Murray's Auto, I think. Just look around at your local auto parts stores. You can get them online too. If you have a good, high volume air compressor, you can use one of those venturi-style vacuum pumps. They are pretty cheap...I got mine from J.C Whitney, I think. That's what I have and it works really well.

[chilort]

Once again, thanks for the great information. I did replace the dryer when I installed everything under the hood. This is probably the 3rd or 4th dryer that's been in the system in the past 2 months. As far as I can tell or see, there is no bits of dryer in the line.

Am I wrong in guessing that if the system were freezing it would work very well for 15-20 minutes before it froze up and started causing the milky consistency of the R134a? If it's more like 15-20 seconds, then maybe that is the issue. Otherwise, it isn't.

Thanks for the great suggestions again.

Oh, and could you give me a quick run down on why the new condensers don't work as well as the OEM part? If it is pure experience, that's fine, I'd just like to know.

[MiniMopar]

How long it takes to freeze depends on how much moisture is in the system. My first car did this when I got it. It was very low, but still had some pressure so we decided not to open it up. We starting adding R12 and the high pressure would be OK, then suddenly start to build to 300-400psi, hold there for a bit as the low side came up, and then it would suddenly drop back to normal levels. It was a long time ago, but it happened once every 30 seconds or so as I recall. After a while, the discharge hose blew off of the condenser.

As far as condenser performance, it was just an observation. Both of my parents had TMs, I've owned 5 and my sister had one. With the exception of the Daytona, all of them lost their charge due to a failed condenser. Usually the compressor shaft seal showed signs of leaking too. We would top them off until the leak was bad enough that it was time to fix them. The performance always recovered when they were topped-off.

We'd replace the condenser, put all new seals in the compressor, and buy new lines for it. When we were done they all would exhibit degraded performance. Don't get me wrong, these A/C systems were never that great. But the difference was noticeable and the only component that was changed was the condenser. Add to that the obviously different design and we decided that it must be the culprit. One other factor that we didn't consider were the new lines. The OEM lines are all steel and rubber while these aftermarket lines were aluminum and rubber. The losses on the cold side were probably higher due to this, and this may have contributed. I now insulate the low pressure side on both my cars. It seemed to help a bit.

[chilort]

The first car I ever bought with my own money (I'd been driving one of our farm trucks) was an '88 NA Daytona. It had already been converted to R134a and it was okay. I know they don't cool all that well. But I expected the '86 to be better than the '88 simply because there is actually a way for the air to get through in an '86. :eyebrows:

Is there a way to pressure test a condenser? If so, I may do that, then reinstall the OEM condenser and keep the other one for "just in case."

Great tip on insulating the aluminum part of the line. I'll have to give that a try. What did you use?

I've also taped the gap between the radiator and the condenser with high temperature tape. I don't think it helped much. When I take it all apart I'm likely going to try to fill the gap all the way around. I wonder if weather stripping would hold up to the heat?

For now I'm stuck driving my '68 Sweptline with a 440 getting 10-11mpg and also with no air conditioning. I need to get this car back on the road to save myself gas money at the very least. Though the passenger side seat does look funny take a space at our kitchen table.:D

[chilort]

I just asked a really stupid question, "is there a way to pressure test a condenser?" Of course there is, you put it in a tub of water and put air pressure to it. Of course, my compressor is at a friends house about 50 miles away and he is currently out of the country. Drat.

Also, here's a picture down into the heater box after cleaning out some of the muck. Should there be any insulation around the evaporator? This was the way FS put it back in.http://farm2.static.flickr.com/1356/967323793_6fda9432c9.jpg (image hosted by Flickr)

As for the Ester oil, that's what FS recommended and also what the tech line recommended when we called to find the exact amount to use (a can of Ester is 8.3oz). Actually, we didn't get the exact figure. Their oldest records went back to '89 and I figured that was gonna be close enough.

[MiniMopar]

The stocker has a sort of aluminum frame with some foam tape on it. Anything to force the air through the fins will help.

For the insulation I used normal pipe insulation, probably for 3/4" copper. Not the stiff open-cell foam stuff but the softer, denser foam stuff. The adhesive along the edges can't take the heat, obviously, so some careful application of tie wraps and a spiral of harness tape ("friction tape") will help hold it together. I've seen remnants of similar insulation on stock cars.

[chilort]

Thanks! Yes, looking at it, especially where the inlet and outlet are, there's huge gaps for air to get around. I was watching a movie tonight and thinking about it and it just hit me, "that can't be right." Off to Lowes or something like that tomorrow to find some insulation. FS really sucks.

[chilort]

Oh, and how in the heck to I get rid of this "Mitsu booster" designation? Even if my '86 CS didn't have a Garrett -- and it does -- I still wouldn't think that was funny.

[TurboJerry]

I assume you're talking about the evaporator? I've had enough fun with them. I like the OEM replacement best, but since they are NS1 now, I don't know what to do? I will say the '91+ condenser (in front of the radiator) with the many small round tubes will give better cooling, but is more fragile. The small minivan condenser seems abnormally efficient as well..... I've been putting the '91+ setup with the compressor that has the high pressure switch on it on cars and has been great. The hoses are the nylon barrier type on those setups from Mopar. So I use all the old hoses and just change the drier and gaskets/seals and no problem sofar.......

[MiniMopar]

Oh, on the subject of seals...watch out for the drier seals when using the aluminum aftermarket hoses. The goofy, offset stud seems to create uneven pressure in th aluminum and I have had them leak. Instead of the stock steel/rubber seals, I put a thin HNBR (green) o-ring around the tube (just get one of those Autostoned kits) and make sure the drier seat where the o-ring will contact is smooth and not coated is Krylon or whatever they use over in China. Works like a champ. The rest of the steel/rubber seals work fine as long as the sealing surfaces are smooth and clean. A little refrigerant oil on the seals helps them seat.

If your aftermarket hoses are like mine, they use o-rings on the compressor connection too. They work better, but you should replace them when swapping the compressor if they have been heat-cycled a few times. I've tried using standard o-rings here and they leak. I guess they just can't handle the thermal cycling. I haven't found that size o-ring in HNBR in retail anywhere. Have to order them online, I guess, once I figure out the dimensions.

[chilort]

This is just a ton of great information here. Thanks for all the help.

I have no idea what to do about evaporators being NS1. I guess I'm just going to stuff foam around this one to try to make it work. I think I'll post some pictures of what I do so that others can follow if they need.

I'm a regular member on Moparts.com. When a post hits this level of detail and information it usually gets put in the tech archive if there isn't something like it there already. I dunno if there is anything like that here, but this is some really good stuff.:thumb:

I'll also have to look into the '91 parts to see what's there. My friend with my compressor has a '92 Daytona. The compressor and lines are long gone, but I think the condenser might still be there. I'll have to take a look.

[MiniMopar]

I'm glad it was helpful. I am one of those people that doesn't handle the heat very well. Makes me cranky with a short fuse...not a good combination when dealing with rush hour traffic. Working A/C is money well spent for me. My dad was the same way, thus the great lengths we went through to keep the A/C working in these cars.

I'm sure you can fill in those gaps around the evaporator with something from the hardware store. A plethora of different kinds of foam weather stripping is available. Just make sure to get the closed-cell foam stuff. You don't want it acting like a sponge for the condensation and getting moldy on you.

Another note about these compressors: they rust internally once the system has been exposed to the elements for a while. Every one I have opened up over the years that were left open (no pressure in the system) for an extended amount of time (say a year) were all rusty inside. They are salvageable, but tended to lose some efficiency. They are weird little buggers inside. Six cylinders and pistons riding on an wobbling disc such that they reciprocate in parallel with the shaft. There is a name for this design, but it escapes me. Anyway, the "rings" are plastic (teflon?) and get chewed-up by the rusty cylinders if they are not carefully taken apart and cleaned up. The valve plate, shaft, and misc other internal bits are all steel and the hygroscopic nature of the oil doesn't protect them at all from the moisture. The plates get very rusty making the valves leak, rust gets released into the system, etc.

I have seen this sort of thing lead to the "black death", where the compressor chews itself up and releases so much debris into the system that any new compressor is quickly destroyed by the contamination. In your case, you replaced everything and are probably fine. I reused an old evaporator in the Daytona and was amazed by the amount of solid debris that came out when I flushed it. It wasn't black or metallic, but it was some sort of yellow/brown crud. Someone had done a botched R134a conversion on the car, so it may have been an oil compatibility issue.

As far as the condensers go, there isn't much choice. I am lucky to have an OEM unit in the Daytona, but I expect it to fail at some point. I think it is the winter road salt that eats through the bare aluminum, or the exposure to road debris. If it's the latter, that may explain why this one lives. The early Daytona nose fully encloses this area and the lower inlets are guarded by the bumper support. I dunno. I have an aftermarket minivan condenser in the CSX. My thinking at the time was to uncover the stock IC and improve its efficiency. It also clears the way for IC tubing if I go with an FMIC. It's a little taller and thicker but not as long as the stocker. With it just hanging out there like that with a clear path around it by the IC, performance was dismal until I added a small pusher fan. That made a huge difference, but the Daytona's A/C is still better.

[TurboJerry]

This is just a ton of great information here. Thanks for all the help.

I have no idea what to do about evaporators being NS1. I guess I'm just going to stuff foam around this one to try to make it work. I think I'll post some pictures of what I do so that others can follow if they need.

I'm a regular member on Moparts.com. When a post hits this level of detail and information it usually gets put in the tech archive if there isn't something like it there already. I dunno if there is anything like that here, but this is some really good stuff.:thumb:

I'll also have to look into the '91 parts to see what's there. My friend with my compressor has a '92 Daytona. The compressor and lines are long gone, but I think the condenser might still be there. I'll have to take a look.

I think you'll have no trouble with the aftermarket evaporator. When you seal it with the foam, make sure it can still drain the water out properly, or the water will eat through the evaporator in about 2 years depending on your climate. (humidity) The 91+ compressors are made by Sanden, they seem to be indestructible.

[MiniMopar]

Some are Sanden. Denso made the 91+ compressors too, so watch out. I've done some research on this, since I hate the Densos so much.

For the record:

Before 1991, the compressor was the Nippendenso model C171/A590. It was used on all kinds of Chryslers, not just the 2.2/2.5. Sanden made a drop-in version of their 709 series for our cars for a brief time (it required special hoses, as I understand it). The model for this variant is the SD-709CA or SD-709CC. If you can find one, you are golden, however they were never installed from the factory as I understand it. Maybe they were dealer-installed kits or aftermarket replacements for a time.

After 1991, the compressor was the Nippendenso model 10PA17C. Sanden was also the 2nd source for this new model as well and they are a bit easier to find in the yards. I don't know the model number off the top of my head.

[TurboJerry]

Yup, I look for the Sanden sticker on the unit, but the hoses are the same. (91+) I took the denso hoses because they were in better condition, and bolted them to the Sanden unit and worked like it was meant to be. I always find the Sanden units, so I don't know if it's a CA thing, but I've seen very few 91+ Denso units.

[MiniMopar]

Cool, thanks. I intended to go with the 91+ setup on the Daytona, but I don't have much time to hit the yards these days and I was frickin melting a few weeks ago in this damn construction traffic. It is good to now the Sanden units are plentiful in that version. They are quality units that are actually designed for R134a.

[chilort]

I should have asked questions here long before I started this project. I simply bought a rebuilt version for my '86 thinking anything newer wouldn't bolt up. I should know better. Chrysler made just 1 of many things. Of course, the moment you go to count on that is when they decided to make 2. Well, I might see if the auto parts store will take the '86 version back for a '91.

What is different that makes the compress "designed for R134a" versus "designed for R12?"

[MiniMopar]

R134a needs more head pressure to condense it down to a liquid and get reasonable performance out of it. I think the required volume of flow also goes down, so the compressor needs more emphasis on pressure and less on volume. It's not a huge difference, but the problem with the A590 is it has sealing problems anyway. The higher head pressures just accelerate its inevitable demise. It's just not a good design and the casting quality is also poor, adding to the sealing issues. At least that is my take on it.

The 10PA17C is a totally different design and uses different lines as well. With the later lines come some extra widgets, like the freeze sensor near the H-valve. You can probably get away with not hooking this up, but I would wire it in so that the compressor was cycled as intended. The H-valve might be different too...I'm not sure. The connection to the evaporator is the same, though. I suspect the condenser and drier are also the same, but I have never looked closely at a 91+ car.

[Turbodave]

The 10PA17C is a totally different design and uses different lines as well. With the later lines come some extra widgets, like the freeze sensor near the H-valve.

90 Might be an oddball year because my Voyager has that freeze sensor (it's bad and that's why it had no A/C at SDAC-15 until I bypassed it) and the older style compressor.

The 91 up cars also had a different mounting bracket for the A/C compressor, so if you were going to swap a 91 up compressor on an older car the bracket woud need to be changed.


Of and Chilort, the mitsu booster title is given to all new members, not meant to be offensive, it just indicates your are still relatively new to the site. Once you reach a certain post count it will change to Garrett booster. Or if you decide to become a contributing member you can change it to whatever you want.

[MiniMopar]

Yeah, I remember that. Does your 89 have it?

[Turbodave]

Yeah, I remember that. Does your 89 have it?
My 89 van was different, as were the lines I got from an 89 van. The lines for the 90 were listed as one year only and new ones aren't available, even through the aftermarket. I got lucky and found good ones on a j-yard van after mine blew (the alternator rubbed a hole in the high pressure hose which makes a cool noise by the way).

[BIGBRUDDA]

I haven't heard anyone mention VACUUM ing the system yet.:D With all the new parts and work, maintaining a seal and moisture elimination(especially in HOTLANTA in july) will take a concerted effort.:amen:
Bolt it all together ,charge system with 100psi Nitrogen.
Now check for leaks.( detector + bubbles):nod:
Vac system THOURGHLY ( 1-200 microns) It may take a while!;)
Add 2-2.5 OZ oil, + dye if ya want
Charge with R134 @ 80% of recomended R-12 volume.
I like to top mine off to 40 psi suction@ idle.:)
When running a car A/C stationary ,spray(mist) the condensor occasionally with a garden hose(when the high side builds over 225psi).:thumb:
You're lookin for 35-40psi suction,& 50-55deg(closed cabin,recirc posistion) discharge air temp:rockon:
Or ya could call an A/C man!:number1: Lots of us do this work "on the side".Usually for a few bucks and a case-o-beer!:dancingbana:

BIGBRUDDA'Z mah name, COOLNESS mah game:cool:

[chilort]

Well, I ran to an auto parts store and a home supply warehouse today to get parts for putting things back together.

AutoZone had the HNBR o-rings.
http://farm2.static.flickr.com/1189/976006269_347fd8c2c0.jpg
How should I choose the correct size? Go with what just fits over the tube?

I also took another picture of the evaporator. Look at all that space for warm air to bypass. What in the heck was this thing supposed to do without insulation????? :confused:
http://farm2.static.flickr.com/1075/976006301_8184be5262.jpg

Time to start foaming. I bought polyethylene pipe foam. The package says it is a closed cell foam. Guess we'll find out.

I've got two more questions.
1) How do I vacuum down the system?
2) In my haste (and stupidity) to get the heater box out I disconnected all of the vacuum lines without drawing a diagram. Can someone tell me where they all go? Would it help if I uploaded a picture?

[chilort]

BIGBRUDDA -- I grew up in the Louisville area. I love it and miss it. That area has the southern charm and hospitality with the speed of the north combined. Things run a little to slow down here in the south. If you were here though, I'd gladly provide the beer.

And the reason I am currently doing this myself is because I already payed an A/C man at Firestone to do the job and am convinced they couldn't find their arses with both hands and a map.

[BIGBRUDDA]

BIGBRUDDA -- I grew up in the Louisville area. I love it and miss it. That area has the southern charm and hospitality with the speed of the north combined. Things run a little to slow down here in the south. If you were here though, I'd gladly provide the beer.

And the reason I am currently doing this myself is because I already payed an A/C man at Firestone to do the job and am convinced they couldn't find their arses with both hands and a map.

NO, you payed a FIRESTONE man. :mad: He probably changed tires just before or after your job.
Refrigeration is kind of a"black art" It.s based on scientific principles, but subject to many-a-shortcut, and hacker:banghead:
I,d re install the heater box(follow the directions) and use ALL the screws.
Insulate the EVAP only with foam, or cork tape. So you can verify where it all fits. The spray stuff is easy to lose control of!:mecry:
Fit up all the hoses hand tite. Call an A/C man, or auto air place. Have them seal up the system and recharge it. that way they're" holdin the bag".:nod:
I'll see if I can find a vac control diagram in my factory serice manual.
These systems work very well when prepared properly. It might cost you now, but there's no reason you can't be chilly by sunday.

[chilort]

I did not use spray foam at all. I couldn't imagine trying to dig that junk back out once another part fails. :yuck:

I just used pipe insulation. I should have taken pictures, but I got it all buttoned back up already. Now to go slide a square box around corners and fully into the car.

Yes, I did pay Firestone not the one specific person. And the guy that recharged the system was their A/C guy. He'd been to A/C college (reminds me of Ron White -- he was a tire guy, a tire guy, a tire guy. He'd been to tire college. Must've been absent on lug nut day!).

Well, I bought myself a full set of gauges. I'm really kind of tired of messing around with the people around here. I think I'm going to go through those instructions after I get all of this put back together and see how this is supposed to work.

The only vacuum lines I am confused about are brown, red, and yellow. Everything else is pretty straight forward. And I think (get in trouble for that sometimes) that the brown goes on the can with only one connector.

[MiniMopar]

I haven't heard anyone mention VACUUM ing the system yet.:D

I mentioned it in one of my earlier posts. Of course you need to vacuum down the system. I usually pull it down all the way, let it sit overnight and pull it down again. The idea being to boil all of the moisture out of the system and test for slow leaks. Purge the lines on your gauges with refrigerant before starting to charge it. I use the pressures as a reference that everything is OK, but I've found the sight glass on the drier to be a close match to the required charge (by weight).

Yeah, it's not something that anyone can do, regardless of what the "conversion kits" that you can get from Autostoned may lead you to believe. Some special equipment is needed to do it right.

[chilort]

So, any ideas on where red, brown, and yellow go?

And what about the o-ring size? Just big enough to go around the tube?

I got the box back in. I don't think I'm going to button up the car until I know this works. Too much work to put it all back together if I have to take it all back apart again.

edit 1 - and someone had asked about making sure my fans were correct. I just checked the on I have on the front of the condenser and it is correct. That is the only one I was worried about.

edit 2 - I do have a question about putting a vacuum on the system. If that is designed to get all the water out, then what is the purpose of the dryer?

[MiniMopar]

The drier can only scavenge so much and it is a slow process. It also acts as a filter to protect the H-valve and compressor. You want to get a head-start and the added protection to internal components by purging foreign gasses from the system, including water vapor.

For the o-ring, yeah just big enough to snuggly fit around the tube.

[chilort]

Cool. Thanks again for the info. I figured out the tube routing situation. I just trial-and-error'ed it until I got it working. I did try charging the system myself and found I have a leak at the condenser. I thought I might, but wasn't sure. My old condenser was working. I'll likely clean the bugs out of it and throw it back in tomorrow.

I found a couple of things in this entire process that I think lead to the system not cooling very well. First, of course, is that silly evaporator with all the room around it for hot air to blow by. A significant amount of air is going to blow by it too since going around is much easier than going through. The second thing was the adjustment for the door for the heater core. I don't think it was adjusted properly because even when the car was on vent only the air would be warm. But I've adjusted that link for the door some and it felt like 87* outside air blowing through, not 100*+ air.

For right now, and I know it sounds stupid, but I need it running, even if its about 70%. The truck will kill me in fuel mileage and it doesn't have A/C either. It has an aftermarket system in it. If I can figure out how to make this junk work on the Daytona, the Sweptline is next.

[chilort]

As you've likely noticed I listen well sometimes but not others.;)

I replaced the leaking condenser this morning with my old one. I also foamed (tape foam, not spray) around the edges to help close the gap between the rad and the condenser. I used zip ties to hold it in place. I don't currently have the capability to vacuum down the system.

I recharged the system. I still don't have it quite up to the spec listed on the sheet that came with the gauges (35 or so low side and it would get near 250 on the high side but I kept spraying the condenser with cold water bring the high side down to 200 or so -- this was after 3 13oz cans), but I was cooling down to 60* in the cab on an 88* humid Atlanta day while not moving. I am VERY happy. Now to go to Firestone and see how much of my money I can get back. I might even go pick up another can of R134a. Oh, and the milky consistency of the R134a as it went by the site glass is now totally gone.

Happy happy happy happy happy happy!!! Thanks a million. You all rock.:thumb: :D :thumb: :D

[chilort]

Okay, I was not as successful as I originally thought. I guess by spraying the condenser I was able to put too much R134a into the system. Once I took it out for a road test it didn't work so well. I came back and all the numbers were way over.

By the time I was done, which included quite a bit of trial and error, I ended up pulling the stupid aftermarket fan out and reinstalling my old one. Now, with the old fan back in and a little tweaking, I got it to cool down to 60* on the highway (on a 90* day) and about 70* stopped or rolling slowly in traffic. It ain't perfect, it's better -- it's good enough.

[TurboJerry]

R134a needs more head pressure to condense it down to a liquid and get reasonable performance out of it. I think the required volume of flow also goes down, so the compressor needs more emphasis on pressure and less on volume. It's not a huge difference, but the problem with the A590 is it has sealing problems anyway. The higher head pressures just accelerate its inevitable demise. It's just not a good design and the casting quality is also poor, adding to the sealing issues. At least that is my take on it.

The 10PA17C is a totally different design and uses different lines as well. With the later lines come some extra widgets, like the freeze sensor near the H-valve. You can probably get away with not hooking this up, but I would wire it in so that the compressor was cycled as intended. The H-valve might be different too...I'm not sure. The connection to the evaporator is the same, though. I suspect the condenser and drier are also the same, but I have never looked closely at a 91+ car.

I've only seen the "freeze" sensor on the outside in vans/trucks, the cars have it inside the car. It has a long spike that goes through the evaporator! I believe the '90 and older cars don't have a freeze sensor at all, but I don't know for sure. (maybe L-bodies?) When I put the '91+ setup on older cars, I hook up the high pressure switch in series with the low pressure switch on the H-valve. They seem to work perfect. One of the ones I did was on a '83 Rampage, and it fit like it was that way from the factory. I find all the hose connections to the car to be the same throughout the years that we deal with. (up to '95) The H-valve is the same, the drier is the same, just that it has vibration mounts insted of rigid mount. I prefer the '91+ drier because you can free up some room by the accessory belts on an L-body.

[MiniMopar]

Good info, thanks.

Glad you have A/C now. Hopefully it holds up for you.

[chilort]

Seems to be holding up. Keep your fingers crossed.

Those green o-rings are GREAT. I bought a cheap-o set of gauges and have already replaced one of the stock high side o-rings with the better kind.

Also, for those that are interested, I am getting all of my labor costs back from FS since I had to redo the entire system myself. They really didn't even flinch. Sad to have to go this route, but at least I recoup some of my costs (broke Ph.D. students need all the help we can get). And, wow, I learned a lot.

[chilort]

Well, it is a sunny 99* with a 104* heat index here in the ATL at 2pm. My A/C is cooling down to 70*. I just had the windows tinted slighly darker than legal to help out some. But 70* just isn't cutting it (but soooo much better than nothing at all).

I was following some suggestions here to run the high side pressure around 225. The chart that comes with the manifold says to run the high side quite a bit higher on these really hot days. My low side is still in the "blue" range, but if I run the high side like they say (around 275 if I remember correctly - at school right now, not home where the chart is) then I'm in the "yellow." I would also think I run the risk of stuff blowing up at those pressures.

What do you all think? Do I go get another can and give it a try? What happens (other than starting to blow stuff up) when a system is overcharged?

[MiniMopar]

The low pressure side will not blow up, but what can happen is compressor damage.

First, the higher pressure will keep the cutout switch from cycling the compressor. Test it by revving-up the engine to cruising speed (say 2000-2500 rpm) to see if the comp can draw the low side low enough to make it cycle off. Check the high side at this time to make sure it is not over the maximum limit.

In extreme cases, the liquid refrigerant will reach the compressor's suction port and damage to the compressor will result. It will clack angrily when this happens.

Does the heater bypass valve work? Does the fresh air/recirc damper shut-off the outside air intake properly? Does the mixer door bottom-out when set to "Recirc" and seal off the heater core?

[chilort]

Okay, more fantastic information.

I do believe the recirc door does shut properly and all the way (though I will double check -- all my foam in the heater box was still in really good condition).

How do I know if the heater bypass valve is working? This is the plastic part out under the hood with like 4 hoses going to it that breaks annoyingly because it is plastic, right? Well, it is new since FS broke that. I'm not sure if it is actually working though.

I can make the compressor cycle, but I'm not too sure of the RPM. I run on the highway at those RPM ranges, so wouldn't it cycling there be bad? I will check the pressures at this range and report back too.

The clacking noise! This I've heard. If I really crank out the RPM then it will start clacking. I would have described it as more of a buzzing. But I bet we're talking about the same thing. So what's going on with this? Is the compressor shot because of this? It is a rebuild. I may have to take all of the previous I've received from many places and just go buy a new one.

Oh, and my cart says at 100* ambient the low side should be 50 to 55 and high 315-325!!

[chilort]

All the doors appear to actuate properly. The mixer door does bottom out. The recirc door is hard to tell, but the vacuum can feels like it is doing its job.

Also, the heater bypass shaft was all the way in the vacuum can when the system was set to cold and all the way out of the can when the heater was set to hot. I guess it is working.

Here were my readings:
Lo Hi
Idle 50 250
2500 30 300

The compressor does not cycle at 2500 rpm.

I did go ahead and bump up the pressure.

Lo Hi
Idle 50 325

I then took it out, included some highway speeds, and there was no difference in the air temp coming into the cab (70* when rolling and about 75* when at a long stop). Outside air temp is 99* and the heat index has dropped all the way down to 103*

At 105, the chart recommends 50-55 low and 330-335 hi.

The refrigerant passing the site glass looks fine (before I had the fans correctly it was really milky -- that's all gone). I've covered my cold line from the compressor to the evaporator in insulation, but if I pull the insulation back I can see that it is sweating some and is very cold to the touch.

One thing I've noticed is that the needles on the gauges tend to bounce at the higher hi side pressure. By the way, somewhere around 2000 rpm I have what I would call a clacking noise, but then at much higher rpm I have a buzz. They are different. I'm just about ready to look for a new compressor.

[By the way, someone earlier (Russ maybe) mentioned that the pistons in these compressors run parallel to the shaft. I found that really interesting. Then the other night was watching the History Channel and it turns out that this style of compressor was invented during WWII for the high pressure hydraulic systems on warplanes.]

[chilort]

I am, as usual, a victim of my own ignorance.

That was a great tip about filling the system to where it cycles in the 2000-2500rpm range. That is a much lower system pressure than what this stupid chart recommends. As far as I'm concerned, I think I'm going to burn that stupid cart.

So the system, upon a second test drive was MUCH worse after filling it up to the pressure on the chart. I evacuated off the low side for quite a while. I now have the system set to where it cycles around 2000-2500rpm. Even just sitting the air temp coming from the dash is around 60-62*, not 75*. And when I started cruising around it would get down to 58-60*. It is still 98* with a 102* heat index. Moral of the story; burn the chart, set the pressure to where it will cycle the compressor around 2000-2500rpm.

I probably hurt the compressor too. The gauges now jump around much more than they did. They used to be rock solid. Now the low side moves some and high side just shakes. The refrigerant past the site glass is also milky again. I wonder how long this compressor will last now? I've got my old core. Maybe I should find a rebuild kit for it and get it ready.

[MiniMopar]

Always good to have a spare with these suckers. Just remember to store them in a dry place so they don't rust on the inside. I would just leave it alone until something changes.

Glad to hear you got cold air again. It's been hot here and I've been so happy to have air. Now I just need to fix the vacuum leak that makes the air go to the floor when I hit the gas.

[MiniMopar]

By the way, someone earlier (Russ maybe) mentioned that the pistons in these compressors run parallel to the shaft. I found that really interesting. Then the other night was watching the History Channel and it turns out that this style of compressor was invented during WWII for the high pressure hydraulic systems on warplanes.

Cool. I must have seen that same episode at some point. It sounds familiar.