Brake problem Help!

[cordes]

I thought I had a bad wheel bearing on the omni, and while looking it over I noticed that the caliper bolt had actually backed out on the LF. I put the caliper back on and replaced the pin. The next day I tried to take it to work and the pedal was very hard and the car was moving like one of the calipers was locked up. This may or may not have been the case since I was trying to come out of my garage into some snow, so that could have thrown the feel off I suppose. The brakes were very spongy on my way to and from school.

I can't see any fluid leaking from anywhere and I bleed the brakes with a vacuum brake bleeder deal that I picked up from sears yesterday. The old fluid was very dark brown and I now have clear fluid coming through the system, but it seems like there are still a ton of bubbles coming out also. I am thinking that it is probably my tool that I picked up.

Are there any tests I can do to see if perhaps my MC has gone bad on me etc? I am at a loss here as this is actually the first time I have had to bleed my brakes.

Thanks guys.

[cordes]

If I pump the brake pedal while the car is off it will get hard just like it always would have been, but when I start it (while holding the firm pedal) the pedal just falls to the floor. Is this a bad MC?

[BadAssPerformance]

Were there any signs of fluid leaking on that caliper that came loose? Did you check the caliper on the other side to see if it was loose? See any fluid leaking between the MC and vacuum booster?

[cordes]

I have not checked between the MC and the booster yet, but the fluid level looked great today when I checked it.

[TurboTurismo]

Just in case, maybe take a look under the car at the backing plates(rear just in case one of the wheel cylinders has a leak ALSO make sure that your flex lines bolts to caliper are tight....

Robb

[BadAssPerformance]

If the MC piston is cracked the fluid wont all just run out at once, instead it will be a slow leak. Even with a slow leak the fluid coats everything... kinda like how a teaspoon of blood from a cut finger can make a mess like OJ Simpson's house. The fluid leak past the piston is the mushy pedal, sometimes it may not leak out either tho.

I think you did everything to bleed it... got clean fluid now, bled all 4 corners in order, RR, LR, RF, LF... should be good. If you question the bleeder tool, look for bubbles in the vacuum line while pumping. Or go old school and have Joy pump the pedal while you manually close the valve.

[cordes]

I think I will try to have Joy jump on the pedal for me in a bit. I need to run out and get some more brake fluid though. I went through quite a bit of it flushing the system thoroughly. So far it looks like I have done everything right, but the results aren't there. Perhaps old school will again prevail. I will update this thread as "new ---- comes to light" as The Dude would say.

[turbovanman²]

What could have happened is the usual, you've removed the old crap fluid, put new stuff in and now the MC has let go. The pedal should sink a few inches when the car is started. If it goes to the floor and you've got no leaks, the MC is bad. Air in the vacuum bleeder is normal due to it pulling air past the bleeder screw threads.
I like to use the vacuum bleeder, then use a piece of vacuum tube, clear water bottle and fill with some fluid, keep the loose end in the brake fluid, open the bleeder, have your helper push the MC down, tighten bleeder, have helper release, wait a few secs, repeat then leave the bleeder open and have them pump up the brakes, aprox 3-5 times, then close, release pedal, then open bleeder, one final push and your done. This is a great way to flush the fluid and remove all air. It might be overkill but it works,

[BadAssPerformance]

^^^ +1 thats old school bleeding 101 with a helper. I got a piece of clear vinyl tube with a check valve on it for liek $3.99 from Murrays Auto that is the same thing but you can DIY with the check valve

[cordes]

Hey guys, I picked up a new MC while I was at autozone just in case the brake bleeding failed miserably. I picked one up for a 88 D150, and it is cast iron. That will be too heavy to hang off of our brake booster won't it? Where can I get an Al one if this one is not going to work? Thanks.

[cordes]

Just got back in from bleeding the brakes old school style. There was quite a bit of air in the lines which is probably from my "bleeding" earlier in the day. I think that myself and Joy have the two person method down now.

Unfortunately the pedal is right where it was the other day on the way to and from school. The brakes will work, but they won't stop you fast at all. How should I check to see if it is the MC or the brake booster? I would like to know for sure. Also, with the caravan brakes on the front, and R/T brakes on the rear, which vehicles MC should I call up the parts stores for to get an Al one?

Thanks guys, you have been a ton of help.

[turbovanman²]

A failing brake booster will give you a hard pedal, there is a mechanical connection between the 2 so the only failure for the booster is lack of assist.

Order up a 24mm master cylinder, just get one for a 89 Minivan, then you know for sure youg etting one. Nothing wrong with cast iron, I've been running one for 3 years-I think there cheaper to make. Oh and make sure to bench bleed the MC or you'll never get all the air out on the car.

[cordes]

Right on. I should be all set then. I will replace the MC tomorrow and report back. If I can't get this going I don't know what the deal is. I have read a couple reports of seals around the piston letting in air before, and I did have that LF caliper pin back out recently so that could have messed it up, but I think that is going to be a stretch.

Thanks again for your help everyone.

[turbovanman²]

Right on. I should be all set then. I will replace the MC tomorrow and report back. If I can't get this going I don't know what the deal is. I have read a couple reports of seals around the piston letting in air before, and I did have that LF caliper pin back out recently so that could have messed it up, but I think that is going to be a stretch.

Thanks again for your help everyone.

I had a reman caliper that let air in, took me forever to bleed and couldn't figure out why I couldn't bleed the right front. I got frustrated and came back in the morning, it had leaked some fluid out overnight so that sealed its fate that I got a bad one. Replaced it, no problems,

[cordes]

I had a reman caliper that let air in, took me forever to bleed and couldn't figure out why I couldn't bleed the right front. I got frustrated and came back in the morning, it had leaked some fluid out overnight so that sealed its fate that I got a bad one. Replaced it, no problems,

Interesting. I will have to check that tomorrow. The left front seemed to keep letting out air over and over again for some time. Perhaps that is what is going on with mine too... We will see when I get this new MC in.

[cordes]

Well, I replaced the MC on the omni with one off of the 600, and I am right back to square one. I think I need to replace the caliper on the L/F as there was a grinding noise coming from the brakes up there when I backed out of the garage. With the omni down from a brake problem and the Neon doing the same thing I am about ready to brake down and cry (pun intended).

We are going to snag a $25/day rental and run around to some parts stores to get this sorted out. Anymore tips or experience with similar interesting problems would still be appreciated, as this has been a real doozie.

[cordes]

OK, the Omni has pretty much been sitting since I last updated this thread. I am going to try and replace the front caliper and pads since they look rough after further inspection. I got some of the speed bleeders with the check valve in them since Joy will be out of town until Tuesday. I also have a new caravan MC to install if the new caliper doesn't do the trick.

I will update this thread when I get back in. Hopefully it will be with good news.

[cordes]

OK, I just got back in from outside, and I have the Omni braking now. Unfortunately for me the parts store gave me a regular MC, so the car sure doesn't stop like it should when I mash the brake. It is now apparent that the MC in the omni went, and the MC from the 600 that I swapped into the car was bad also. When it is time to get the 600 rolling again I will just swap the MCs. Fun, fun.

Thanks so much to everyone for all of their help with this problem. It really through me for a loop when both the MCs were bad.

[turbovanman²]

OK, I just got back in from outside, and I have the Omni braking now. Unfortunately for me the parts store gave me a regular MC, so the car sure doesn't stop like it should when I mash the brake. It is now apparent that the MC in the omni went, and the MC from the 600 that I swapped into the car was bad also. When it is time to get the 600 rolling again I will just swap the MCs. Fun, fun.

Thanks so much to everyone for all of their help with this problem. It really through me for a loop when both the MCs were bad.

Thats why you should never, ever mess with M/C's, just bite the bullet and buy a new one.

Should have ordered the M/C for a Minivan, that way, your guaranteed the 24mm, just like I mentioned in post 12,

[cordes]

Thats why you should never, ever mess with M/C's, just bite the bullet and buy a new one.

Should have ordered the M/C for a Minivan, that way, your guaranteed the 24mm, just like I mentioned in post 12,

I did. I got a MC for an 89' caravan. The guy asked me if it had the 14 or 15" wheels. I said 14" because I thought that is what the turbo minis came with.