bench testing heater and AC cores

My HVAC system is on the floor of my garage and since it is a PITA to test the heater core in the car. I am planning to bench test.

Heater cores:
Since I have multiple(approx 6) heater cores I was planning to test as many as possible.
After clean the core inside and out,I was planning to chemically clean the inside. I will pressure test with compressed air to 20psi with shop air using a soap solution looking for bubbles. I will install in the heater box and connect to hot water from the tap and adjust the flow. I will measure the input and output water temp while the heater fan is running at full. I will also measure the output air temperature.
AC cores:
Just use a simple pressure test after cleaning. This worked well with my Sundance AC addition.

Any other suggestion???

time to reach each ten degree point ..

some heater cores are better N others

backing my carbed turismo non a/c out the driveway at the top of sheppard and driving down to the lights at hwy #2 I'd have heat .. good heat as I turned at #2

mile -ish - + to non locals

Why? A new heater core is ~$25... Maybe for an evap core at ~$90. The big deal is usually the labor to replace them.

Look for any signs of a leak (ie. corrosion.) I would fill it with water, cap one end, pressurize it and seal the other end (ball valve) and watch for a pressure drop...

On the evap core, testing them in place is pretty easy. Put the AC leak detector in the AC condensation drain. Note that leak detectors can be set off by air movement, so best to do it with the fan/engine off...

Quote:

---

Originally Posted by c2xejk

Why? A new heater core is ~$25... .

---

Yes but mine appears to be in excellent shape and are original mopar copper. I am concerned about poor quality aftermarket stuff. It is not a money thing

Miles easy to submerge the heater core in water (utility tub or something) after pressurizing with air. I won't install ANY heater core without doing this first. I'm only doing that job once... Having cleaning solution reverse flowing through core is best. I use an old fuel pump as my pump. Also make sure the heater core nipples aren't crushed at all by over tightening hose clamps. Also clean up nipples of any corrosion or residue from old heater hoses. Some of those hoses are pretty much welded to the copper nipples.
I use sulfamic acid crystals to remove mineral deposits, followed by some white vinegar, followed by a nice water rinse.
Todd

Quote:

---

Originally Posted by chromguy

Yes but mine appears to be in excellent shape and are original mopar copper. I am concerned about poor quality aftermarket stuff. It is not a money thing

---

I checked a while ago on heater cores for l-bodies. I could still find some NOS stock of copper brass heater cores for non AC cars, but nothing but aluminum Chinese cores for AC equipped cars. I would be very cautious of using aluminum cores, esp. because of the electrolysis issue, and the quality issue. I'd rather use a cleaned used copper/brass one vs. a new aluminum core for sure.
Todd

Quote:

---

Originally Posted by 4 l-bodies

Miles easy to submerge the heater core in water (utility tub or something) after pressurizing with air. I won't install ANY heater core without doing this first. I'm only doing that job once... Having cleaning solution reverse flowing through core is best. I use an old fuel pump as my pump. Also make sure the heater core nipples aren't crushed at all by over tightening hose clamps. Also clean up nipples of any corrosion or residue from old heater hoses. Some of those hoses are pretty much welded to the copper nipples.
I use sulfamic acid crystals to remove mineral deposits, followed by some white vinegar, followed by a nice water rinse.
Todd

---

I like the idea of the fuel pump but I only have new Deatschwerks pumps on my shelf. The other tips are also helpful, I was going to use sodium citrate for scale but I will try the sulfamic acid.

Quote:

---

Originally Posted by chromguy

Yes but mine appears to be in excellent shape and are original mopar copper. I am concerned about poor quality aftermarket stuff. It is not a money thing

---

The copper ones seem much more durable and seem to last longer than the aluminum ones.

Now my question is, if you find a small leak in a bench test like yours, can you braze or sweat the leak to seal it up?

Quote:

---

Originally Posted by supercrackerbox

The copper ones seem much more durable and seem to last longer than the aluminum ones.

Now my question is, if you find a small leak in a bench test like yours, can you braze or sweat the leak to seal it up?

---

In theory, yes but it depends where the hole is. I have repaired copper rads in the past with a BFG (solder, LOL) but a heater core is much finer. The heater core is not quick to replace in a working car so I would hesitate using a repaired unit.

An update.
I found a used fuel pump so I hooked in up in a 5 gallon plastic bucket. I backflushed all cores with a bit of tide in water followed with water rinse until water is clear.
Next the chemical wash.
I used approx 8oz of sulfamic acid in 2 gallons of warm water. One core was easy to clean with a bit of black stuff that come out. The CSX core was so bad the crud blocked the core which was challenging to clean out. So the sulfamic acid does the job!
The first core clean up like new with approx 1 hour or recycling...very nice btw.

Are you still using conventional coolant ?

Quote:

---

Originally Posted by 135sohc

Are you still using conventional coolant ?

---

Not going forward. The Sundance was conventional until my cleaning last year. I used Prestone Rad Flush and ran the car for a week or more. Flushed and switched to Thermocure as per your suggestion.Now running Pestone long life orange.
Worked great, it even stopped crackling that was there since new..
The CSX is new to me approx 3 years ago and yes it contained conventional coolant... I want to install a clean know good unit while I have the dash out. I will clean the system out like the Sundance once we are on the road..

Coolant options have changed a lot since these were designed but I wonder if running a good long life coolant from day one or in our situations when doing a refresh if that should eliminate clogging and failures essentially forever. In theory I'll never run the car long enough to ever 'wear out' the peak global charge I use now. I have changed T-stats twice since first using it and I just pour it through a paint filter on the way back in. Conventional green I would never think of reusing more than once and not even then if its been in service more than 12 months.

At this point, I cannot recommend the use of a fuel pump to pump cleaning solutions.
Here is what happened to two pumps.
http://www.turbo-mopar.com/forums/sh...=1#post1152349

I'm weary with newer coolants. GM obviously had many issues with Dex cool. I've seen tons of Ford's and Chryslers form a peanut butter consistency sludge. They both used zerex g-05 type coolant.

Quote:

---

Originally Posted by thedon809

.... form a peanut butter consistency sludge. They both used zerex g-05 type coolant.

---

Ugg that ain't good

Miles, what cores did you test for this? I didn't see where you provided brands and I am looking to buy a new one, possibly a couple just to have a spare. Thoughts on which brands are best to go by? I'm probably going through Rock Auto, so these would be my selections.

Attachment 65888

https://www.google.com/search?q=barb...728&gws_rd=ssl

Random google search but there should be a link to cooling industry service equipment and tools ..in there some where.

the number one thing you want is a couple of "caps"for your rad and heater hose in/outs .. and a couple of bolt on tire valve stems .. one stem for each sized cap.. for sets of two
all you need is a bicycle pump ..

then you can test for leaks in the laundry tub or bath tub ..with some towels so you don't scratch stuff

fix V type rad fins with a blunt ice pick ..

you can buy a "fin comb" for straight style fins.. like industrial rads

and ..you might not want to be "surprised"if a cleaned out heater core or rad suddenly starts to leak..

I ripped the top of my truck motor apart last year ..thought I'd run some water through the heater core while everything was apart..
stuck the nozzle of the garden hose tight to one heater hose and stuck the other in a bucket

well short version .. foggy windshield when I drove it..

'cause the sediment at the bottom was blocking the hole in the bottom..cough ..

heater cores can be fixed easy enough but only if you have access to a "led pot" you can dunk it in .. and compressed air to blow the fins out ..the instant you pull it outta the pot

and that's likely something most of us shouldn't try as dunking things in molten lead is fairly dangerous ..

a wet rad or heater core ..water.. makes lead in the pot suddenly leave the pot..

this is how the brass end plates are soldered to the ends of the tubes in a copper /brass rad

Well I was just looking to get a "good" brand item so I could have some confidence in the longevity of it. I know new cores can fail, but like oil filters and other service items some are better than others. Any suggestions would be appreciated.