Sticking Rear Brakes on 1986 Jetta GLI

My wife has a 1986 Jetta GLI with rear disc brakes. I replaced the rear calipers a couple of years ago, the parking brake cables last winter, and I just installed new brake pads.

Everything works fine till the car sits overnight. Then the rear brakes "stick" making a terrible howling noise and making it difficult to pull away in the morning. Once we drive down the road a few hundred feet or so, the pads loosen up, and everything works great again. But just getting up our steep gravel driveway with sticking brakes is difficult.

I've experienced problems like this in the past, but it was during freezing weather with damaged parking brake cables. Our cables are like new, and the weather is well above freezing.

I've adjusted the parking brake a couple of times, but it has no effect on the sticking problem.

I don't see any kind of "spreader spring" to push the pads apart when they are released, on the car, or in the Bentley manual.

The brakes were sticking before I changed the pads too, but it was more pronounced in reverse than going forward. Now it's about the same either direction.

Any ideas what could be causing our sticking brake problem, and what I can do to solve it?

Thanks,

Anthony

Reply to
HerHusband
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only out of ny experiences with different cars, take everything apart, clean the pad's, in germany VW is using some 'copper' grease to grease the pads (where they slide back). what makes really the difference I found out. Otherwise, try to get a new set of brake pads (from a different manufacturer) and try new ones, I found out that each manufacturer will meet the specifications of the new pads a little different, some are on the 'high' end some are on the 'low' end of the original specs. maybe new pads will slide better and dont get hang up.

please keep me posted. THX Sebastian

Reply to
Sebastian

Reply to
none2u

Sebastian,

That's all I can think to do as well... Thanks for the input.

We've been on vacation this week, so we've only driven the car once or twice since I installed the pads. If it's still acting up next weekend, I'll dismantle, lube, and reassemble everything.

It doesn't seem like a problem with manufacturing tolerances. We're on our third set of pads (all different manufacturers), and every one of them has stuck like these do.

Thanks,

Anthony

Reply to
HerHusband

come on now this is a no brainer, take the rotor dust dish off ..look at the spring configuration...for broken springs etc. be sure to look at a diagram of the spring set up its tricky...get springs at any auto house many are universal...replace the pads and be sure to check and inspect the emergency cable for breaks...they are a bitch to repair if the cable snaps...at worse you have no emergency brake...so caution is advised on un level surfaces if you have a stick shift...welcome to jetta hell!

Reply to
jonyguitar

If only it were that easy... :)

There's no indication the rear brakes EVER had any kind of spreader spring for the pads, and the diagrams in my Bentley manual don't show any springs either.

I just installed new pads a few days ago, and the parking cables are only a year old and working well.

As I said, the brakes (and parking brake) work great. The problem is getting the brakes not to stick first thing in the morning.

Anthony

Reply to
HerHusband

Sebastian,

Last night I pulled the brakes apart again. Scraped away any rust or dirt, verified the pads could slide freely back and forth without binding, cleaned everything well, and put a light coat of grease on anything that moved. Then I very carefully put everything back together, making sure nothing was binding up anywhere.

We checked and double checked the brake and parking brake operation. Everything seemed to work perfectly, so I drove the car 20 feet out of the garage, and parked it till morning.

This morning my wife got in to drive away, and the darn brakes were sticking again!!! Arghh.... :)

I'm at a loss. I don't know what else I can do to prevent the rear brakes from sticking like that.

Any other thoughts?

Thanks,

Anthony

Reply to
HerHusband

Reply to
none2u

I mean pads. My wife's 1986 Jetta GLI has disc brakes at all four wheels.

I replaced the brake proportioning valve six years ago. I replaced both rear calipers three years ago. I replaced the master cylinder two years ago. I replaced the parking brake cables last year. I just installed the new brake pads last week.

The rear brakes have exhibited the "sticking" problem through all of these repairs, though it seems worse with the new brake pads.

No, I put a "light" coat of grease on the BACK of the pad where it contacts the caliper piston, and a very light coat along the edges where the pads are retained in the caliper.

I also pulled out the caliper guide pins, cleaned off all the old grease, and coated them with new grease.

No, the brakes work perfectly. Apply the brakes (pedal, or parking brake) and the wheel won't budge. Release the brakes, and the wheel spins freely. No noises or resistance of any kind.

Of course, once it sits overnight, the rear brakes stick and drag for a bit till you drive down the road a ways. Then everything works perfectly again for the rest of the day.

I don't think it's a hydraulic issue, as the brakes work perfectly while driving. The sticking ONLY occurs first thing in the morning after the car has sat overnight.

I'm still planning to jack the car up one of these nights and let it sit overnight. I'll release the parking brake and just make absolutely sure that mechanism isn't binding somehow when it gets cold. But, considering how well it works during the day, I have my doubts.

The only remaining item would be the pads rusting to the brake rotor itself as the car sits overnight. I don't know of anything that can be done to prevent that and not reduce the braking efficiency.

Anthony

Reply to
HerHusband

Reply to
none2u

I tried leaving the parking brake off this last weekend. Didn't make a difference. The brakes still made dragging noises first thing in the morning.

In fact, I actually noticed the same dragging noises later in the day after we stopped at a store for a few hours. That's the first time I've heard it other than first thing in the morning. But, the one common denominator is that the car has to sit for a while.

We basically have a hill everywhere we go. Our driveway, work, and most places we visit. A parking brake is basically a necessity for us, and ours generally works very well.

That's on my list of things to try. Just haven't had the time.

All were replaced for other reasons, not because of the dragging sound.

Let's just say it has been doing it long enough that I don't remember how long it has been doing it. :)

Anthony

Reply to
HerHusband

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