1999 Jetta spongy brakes after replacement

It isnt too unusual for new brakes to feel a little weak at first, just after pads have been replaced and rotors either machined or replaced. Usually they "wear in" after a short time and feel normal. BUT: If he replaced the pads, he had to force the pistons back into the caliper. In my opinion, it is sloppy and unprofessional to put everything back together and NOT bleed the system. It is precautionary, and helps remove the possibly contaminated brake fluid from the system. Some say that pushing the piston back into the caliper without opening the system can push crud back into the master cylinder and precipitate early failure. I am not for sure about this, but wouldnt discount it. (I dont do it)

I dont think the problem you are seeing is from contaminated fluid, but bleeding, to me, is a given. (Maybe others dont agree,and that is certainly their privilege)

If your back brakes are not working, you will lose a percentage of your total braking power. Again, I cant believe this mechanic noticed the a problem with the back brakes, and gave it only a superficial tweak.

Loafing back brakes will put undesirable load on the front rotors, and can cause them to fail early.

Was this a dealership, or a franchise like Just Brakes? In short, I dont care for the attitude of the mechanic or shop that did this.

I have a feeling that you don't really know the meaning of "force". Do you have to push the pedal harder or does the pedal just travel farther than it used to? If the rear pistons were stuck and now are free and working properly that would explain a lot. It would explain why the front brakes wore out and needed work. It would explain why the pedal now moves farther. Were you offered the option of having the brakes bled and brake fluid changed for an additional charge? How about the rear brakes did you have the option of doing them also?

-jim

The mechanic has since suggested replacing the calipers - how likely do you think that these are the problem?

This was an independent dealer who specializes in European cars. He did a great job replacing my timing belt, but that is the only other service I've had him do.

Well, I definitely have to push the pedal further in, but I also have to apply more force to the pedal to get it to stop at the rate I am used to. In other words, if I push on the brakes in the way I am normally used to, the car takes a lot longer to come to a complete stop.

The rear pistons have *not* been stuck before. There had been no sign that the calipers had a problem before I took the car into the shop. In fact, the brakes seemed fine before getting the front pads replaced. The calipers only seemed to be stuck when the mechanic took the car into the shop. In this case, he said they were stuck in the "closed" position.

I was under the impression the front brake pad replacement was normal wear-and-tear. (The car has 97000 miles)

No option for either was given to me. After he 'unstuck' the calipers, the dealer offered to replace those - but at $800 I wasn't too keen on him replacing them if they weren't really malfunctioning.

I dont know about the Jetta rear disc system, but some of those four wheel disc systems have, or had, mechanical links to the pistons so that the parking brake will have positive displacement. These can double as adjusters. (Since the link is mechanical, the typical caliper function may not be what you have come to expect) GM had some like this, and they were terrible about the parking brake 'adjusters' freezing. It was not a matter of the pistons freezing in the calipers.

When this happened on the older systems, the parking brake would work, but the frozen adjuster would hold the pads away from the disc or rotor. Bad news.

Again, Jetta may not be plagued with this.

When that happened, the rear brakes did not adjust, and all the load was on the front.

I would assume, or hope, VW does not use a similar system, but dont know for sure. That is why I made a statement about the mechanic not checking the function of the rear brakes.

You got a front pad and rotor job. You didnt get a brake job, IMO. And even so, I would have expected the mechanic to bleed the system.

Your life depends on your brakes. Take it whereever you want, but you really want to be sure they are working correctly.

OK. I would not go back. You need to find somebody you can trust to look at your brakes and find out what's wrong. It would be a good idea to have the brakes bled and new fluid all the way around even if you do nothing else.

-jim

I agree with you, Jim. Something about this mechanic and his attitude doesnt seem to track.

Look, Saxman... If you are in the USA, go to the AAA site, and find their list of approved mechanics. Use this list as a shortlist to find a decent mechanic. You do not have to be a member to avail yourself of this list.

But, overall, AAA isnt a bad deal.

"saxman" wrote in message news: snipped-for-privacy@v33g2000cwv.googlegroups.com...

Hi,Saxton, the following is to educate yourself a bit about your car--NOT to repair your brake system. It'll allow you to talk intelligently to & maybe deal better with a good mechanic. First ensure fluid level is proper. If low, get car on a lift or slide under it & check for leaks. Apply emerg. brake fully, and attempt to drive FORWARD. It should hold & not allow car to move. Release & then find a slight hill/slope & see if car will roll downhill without power from the engine, without emerg. or regular brake applied, & unhindered by any stuck brakes. Assuming it rolls freely, you've now found the calipers are moving in (You said, "Parking brake still stops the car," & now emerg. brake holds car from pulling off when engaged fully.) AND out ( it free-wheels down the hill ). If this test is passed, the rear brakes are working WHEN actuated by emerg. brake mechanism. Now with car on a level surface (parking lot?), idling in neutral, & wheels chocked, engage emerg. brake positively, release, engage, rel....15-20 times, quite rapidly, and w/o brakes applied. Idea is to "pump" & move rear brakes in and out to try and adjust them a little tighter--we're assuming they are to be adjusted this way, a somewhat reasonable assumption. If we are correct, you should now have more pedal, and not have to push it as far in to get stopping action. Another caveat: If your car calls for metallic pads, materials on cheaper, non-metallic pads may require more force to stop than proper, quality pads ; they may be a tad noisier, w/a scrubbing sound that's esp. noticeable on the 1st few stops in AM when they are cold. One last bit of info: a general rule WE mechanics often use is to "adjust up the rear brakes" when a customer complains of lo pedal, & front pads & rear pads/linings are known to be good. Why? Because fronts are not adjustable! Hopefully some of this will help you make good decisions about getting your brakes in good working order--it may be the cheapest insurance you ever buy. And please believe me when I say there ARE some good, trustworthy, & conscientious mechanics out there. Best regards, sdlomi2

Thanks for all the helpful suggestions!

Is there any way to check if the rear brakes are engaging when *not* using the emergency brake cable?

Also, is it possible for a mechanic to really 'adjust' the rear brakes (as in, move the pads closer to the rotor if they are farther away). If so, that might be something to try.

And I know that there are some good mechanics out there, I just wish I had some way to know right off the bat! It's so hard for me to have to take everything a mechanic says with a grain of salt - I *want* to trust them - I've just gotten burned quite a few times.

If the elements of the braking system are working as they should, then there is no adjustment needed on the disc system.

"saxman" wrote in news: snipped-for-privacy@l53g2000cwa.googlegroups.com:

Chock front wheels. Jack up the rear end.

Spin each rear wheel. They should spin easily by hand and continue spinning briefly when you stop pushing. There will be a bit of a scuffing or hissing noise.

Does each wheel spin the same? Do they both continue to spin the same amount when you stop pushing on the tire?

If there is a significant difference between wheels, one caliper's piston is sticking. If both are draggy, then the parking brake may be overadjusted.

This assumes, of course, that all cables, calipers, pads, links and pins are as free as they should be.

All disc brakes are self-adjusting. You've only got a thousandth of an inch or so clearance at all times.

Don't know how VW does their rear calipers, but for Honda products there is no adjustment, EXCEPT for the initial parking brake adjustment. With Honda calipers, the caliper's parking brake lever must be fully home against its post, and the piston be all the way out to the rotor, before final adjustment of the parking brake cable.

With a Honda rear caliper, there is no need to dial the piston out after turning it in all the way. Each pedal press moves the piston out a quarter- inch, so any slack is taken up very rapidly.

They are self adjusting if the adjusters work. They dont, always.

The GM ones, and some others I had seen had mechanical adjustment built as a part of the parking brake system. It was not hydraulically operated. It worked on a jackscrew type mechanism inside the caliper.

In a perfect world, these WOULD self adjust. But when people didnt use their parking brakes religiously, and when the adjuster mechanism became seized, then the rear brakes could no longer self adjust. The pads were close enough to the disc, usually, so that the parking brake cable could pull them to or near the disc surface. But, if the adjusters were frozen, when the parking brake was released, the pads would move back away from the disc.

Eventually they would get to the point that even the parking brake wouldnt work.

At that point, you would have to release the ratchet mechanism and free it with some antiseize. You sometimes HAD TO adjust those brakes manually at that time, because the spacing between pad and disc was too great to allow the adjusters to work.

If you ever saw one of them work, it is easy to understand. It is not so easy to explain otherwise.

The old GM ones were a PITA. I havent seen much problem with the newer all wheel disc designs.

wrote in news:1drwh.6928$ snipped-for-privacy@newssvr11.news.prodigy.net:

Honda ones do, too.

With Honda calipers, each time you step on the brake and squeeze the pads against the rotor, you turn an internal screw. The piston backs off the screw as the pads wear. The screw is what the parking brake cam pushes on as it shoves the piston forwards to apply the parking brake. The screw doesn't turn when you apply the parking brake, only when you step on the brake pedal.

The upshot of the above paragraph is that you can ignore the parking brake entirely and the piston will still remain properly adjusted.

The GM design sounds stupid, frankly. Like those old drum brakes that would only adjust if you were braking while moving in reverse.

And as I said, I don't know how VW does their rear calipers.For all I know, they're just like the GM ones you describe.