Front brakes dragging

did you push the pistons completely back in when you changed the front brake pads?

Carl

First, you need to get the proportioner valve reset. It's the metal block between the master cylinder and the lines out to the wheels. I'm not sure, but I think the 88/89 had a pin you push in but some report having to pull the pin out. Whichever way it goes, blosk it open (or have someone hod it open) and crack the bleed ports on the wheels one at a time. That may let it center. If not, it can be fun getting that !@#$% proportioner valve re-centered - you have to crack a port on one end only while applying SLIGHT pressure. Of course, every time I've tried it I either get too much pressure and.or got the wrong way first...

Replace the fr> did you push the pistons completely back in when you changed the front brake > pads?

On my TJ I had that problem, front brakes dragging I could smell them burning after a while (right after a brake job). Turns out I put one brake caliper bolt in crooked, so the pad wasn't straight against the rotor on the left side. I had to drill out the bolt hole and put a helicoil in it to fix it all. No problems since.

Troy

-- First, you need to get the proportioner valve reset.

I've read about this, but I don't understand how... When I look at my proportioner/combination valve, on the end facing toward the front of the car there is a rubber cap that I pull off revealing a hole. I can insert a hanger or a paper clip into it but there seems to be nothing to push or pull. Perhaps I'm looking in the wrong place? Maybe it's frozen?

If I take off the sensor I can see something in there but can't make out what it is, and there's no fluid that comes out of the sensor hole.

Leave the sensor out, and bleed the brakes properly. If you have a blown wheel cylinder, caliper, or a leaking brake line, the proportioning valve will shut off the brakes at that end of the Jeep and turn on the light. After properly bleeding the brakes, the sensor will center and reset itself. If fluid DOES leak out of the sensor hole, the valve is bad.

If you would like more help, I'd be glad to, just email me direct at:

brysonct AT triad DOT rr DOT com

Spdloader

I was able to 'bleed' the proportioner valve. I lessened the bolt at the end (with the hole in it) and took out the guts, cleaned and reinstalled. Then I left the nut only partially screwed in and had wifey pump the brakes to get the air out and then I tightened the bolt up.

To my Joy, the brake light is now off! Unfortunately the brake still drags. I jacked each front wheel up and found that really only the right side is dragging and the left feels about what I would expect with new brakes... I'm beginning to suspect a bad caliper/piston.

Using a C clamp I can press the caliper open just a little more and the rotor will spin reasonably well, but by the time I replace the MC cover and put the wheel back on its dragging heavily again.

One last thought: could the new brakes be just a little too thick? With the tire on I loosened the caliper bolts slightly and the drag was alleviated. (Its a thought anyway)

Bear in mind the proportioning valve is actuated by outside sources, it didn't switch itself, an external brake problem caused it. You'll have to fix whatever caused it to happen in the first place, or it'll happen again.

By installing new pads, you moved the pistons back into the bore of the caliper, and if they're old and corroded, they'll stick like you describe. Sounds like time for new calipers.

Spdloader

First thing I'd look at is the flex hose to the sticking caliper. They can come apart inside and hold pressure on the caliper. Surprised this thread went this long with nobody suggesting that, but the real clue is that only one side is sticking.

-- Old Crow '82 FLTC-P "Miss Pearl" '74 XLH chopper(somebody else's baby now) BS#133, SENS, TOMKAT, MAMBM, DOF#51, DH#2 "There's only 1 RE"

We discussed that too in a private email.

Spdloader

I would be suspecting the flex hose to that wheel has collapsed internally. This can hold the caliper 'on'.

Mike

That doesn't do the rest of us shit.....

If someone wants help, what use is taking folks guesses to private email?

That just causes a lot of repeats guesses and wasted time.

I 'guess' he must have it fixed by now too?

Mike

Is everybody on a hair trigger in this newsgroup?

Turning the other cheek, I'll say this:

I invited him to contact me via private email because some folks are more comfortable that way.

It wasn't my intent to torque anyone off, sorry if I did.

Spdloader

Sorry to be snappy, but I have been involved in a few fixes that happened partly via private emails and they all took way too long to get resolved with way too many repeated guesses by folks and bad advise given out because only half the story was public....

That 'really' defeats the purpose of the newsgroup.

So I'll ask again nicely.

Did the gent get it fixed because it was a failed brake line?

Mike

Spdloader wrote:

Privately, I advised the OP it could be either the caliper or a brake line, then I reposted the same advice to the group, so there'd be a record of it for anyone else who needed it. Somehow, the text regarding the hose didn't paste.

That's my fault for poor editing.

Since brake hoses degrade slowly, and not usually immediately, I suspect the caliper. The caliper stuck in the bore the moment he pushed it back with a C clamp to facilitate the new pads. Evidence suggests the caliper, but I would never rule out the hose. Neither one of those problems will make the proportioning valve switch over though, so I suspect another problem as well, or something else was done the OP hasn't told us yet.

Nothing further has been communicated. Everyone should be up to speed now,

...and your new knick name is "Hair-trigger Mike".

Where I come from in the military, everyone gets a knick name, but you have to earn it.

lol

Spdloader

Well, I do have my moments, LOL.

I was just a bit frustrated this morning wading through 4 days of mostly crap for posts, then figure ah, one to answer only to find out nope, been done on the quiet....

His brake failure light is/was on for a reason. It means it sees a pressure difference between the front and rear brakes. I have never heard of directly bleeding a modern prop valve. If they can't be bled at the wheels by holding the pin or if they are the 'new' ones with no pin, then if they fail, they are dead. I doubt his has failed.

Mike

Spdloader wrote:

Agreed, his prop valve is fine. We should find out more soon, if he posts his results.

Spdloader

I sent him, directly, some relevant pages from the service manual in PDF format. Should I have typed them all out and posted the information here? How would I have handled the diagrams?

I told him I, as a non-mechanic, suspected the caliper but that more seasoned heads would offer more expert advise.

I also suggested obtaining a build sheet which is something I would suggest to anyone who wanted to know what components were installed at the factory.

Billy Ray,

It would be useful to the thread if all the relevant info was at least referred to. Posting the manual is overkill but everyone knowing the fact that he has the data would save a lot of trying to explain some specifics to him.

When strange crap stats happening, we all could benefit by the process of trying to figure it out all together rather than ten different things being posted and acted on unknown to everyone else. It then can get extremely confusing, especially for the poor OP.

Mike

billy ray wrote: