[Frank3]

I've been snooping around this forum a few days now , and have found a lot of useful info.
But I haven't found anything about the way my rear brakes are acting . When I first got the car , the pedal was high and the car stopped very flat .
While I was waiting for the car to be delivered , I met a guy who asked me about the brakes and the pedal travel on my car , as his had lost some stopping power and the pedal travel had increased . His car was 2 months old .
I also had the same thing happen . The workshop manual said to pump the pedal 3 times then pull the e-brake handle 3 times the repeat . Which I did , and it only helped for a day or so . I asked the dealer , and was told they had never had any complaints , and I should pull the wheels off and check things out . 5000 miles and this is the response at 2 different dealers .
I still haven't done it and have 29k on it , and the e-brake thing isn't working any more .
I had the same problem with a '84 z-28 , but the adjustment was made differently , and GM finally came up with a stiffer spring and piston to fix .
Any body have any suggestions or ideas ?

 

[Fluid]

My guess - air in the brake lines. As the brakes heat up, the air bubble moves and the brake travel changes. Does pumping the brakes twice give any firmer feel?

The rear brakes are clamped by the piston and the e-brake. The e-brake is just a cable that you pull, and it manually clamps the rear brake calipers. The reason why you pump the brakes and then pull the e-brake is because it presses the brake pads to the rotor and also stretches out any slack in the cable. Unless you changed the pads or rotors, there should be no reason to adjust the e0-brake. Look around the FAQ and there should be an article on adjusting the e-brake. If not, just pull the center console and there are some cables and nuts underneath it.

The order for bleeding the brakes is left front, right front, left rear, right rear. Try that first.

Also, you may see references to a regulator, in your car, it's all electronic, the mechanical regulator is only on mk3 and mk4 models without ABS (not sold in the US).

 

[Frank3]

The e-brake cable appears to be correctly adjusted , and air in the system is not the issue . The rear brakes back off ! And as far as the pedal pumping , one pump ( press the pedal , then once again ) stops firmly . The adjuster inside of the piston in the rear caliper , does not stay adjusted . The rear pads back off the rotor too much .
You may have the same thing happening and not realize it . Other people I've asked about their Jettas hadn't noticed , but the next time I saw them they confirmed the same thing with theirs .

 

[chittychittybangbang]

I don't think the adjuster inside the caliper is serviceable. When you go to press the rear caliper pistons back, you hav to turn then while pushing back. It's possible that this is damaged.

It's possible that this is a master brake cylinder wear issue, there's no stains around the inside of the firewall near the brake pedal or on the outside?

It's unlikely that the brake line is collapsing...maybe it's twisted?

 

[Frank3]

This has been an issue since the car was 2 months old , I don't believe that wear is an issue . And there are no leaks .
The reason you have to turn the piston as you press it in is that it has a ratchet / screw mechanism that keeps the piston from retracting back to far . there is also a spring behind the piston to help push the piston out . In other words , it keeps the pads in contact with the rotors . And this is what the problem I'm having is . The pads are moving too far away from the rotor . Not a big problem , just enough to be annoying . and change the bias .
GM put this type of caliper on Caddys , but after having the same problem they changed to the divorced E-brake . And Chevy / Pontiac picked them up for F-body and Fiero . They eventually did a recall , only the manual cars .
Anyway , I just wanted to know if anybody else noticed this or had heard of this whit VW . Or maybe even a cure .

 

[Adamgolf]

I think the opposite, I think the pedal engagement is higher than most cars. These cars use something called electronic brake distribution. There is no manual bias regulator, I think, it's done through the ABS or something, when you brake light it biases the rear brakes, when you brake heavier it changes the feel. I don't know why brake feel would be effected by the e-brake?

 

[chittychittybangbang]

I haven't taken the VW caliper apart but I don't think there's a spring inside the rear brake caliper. I think the ratcheting mechanism is just done by the parking brake, which is why you pump the brake and parking brake 3 times. Looking at the parts lists or the rear brakes, I see no spring behind the caliper piston.

A potential help - always use the parking brake, it'll help ratchet the piston forward.

 

[Frank3]

I do always use the E brake . And if there isn't a spring , it will be the first one I've seen with out it in a self adjuster .

And since no one posting yet has noticed this , my next question of if the larger brakes have the same thing , is mute .

Why change brakes ?
18" BBS RCs.......kind of dwarf the stockers .

 

[Vent5]

You could try asking on the vortex. The 2.0L and I think some other models use the same rear brakes and brake modes are more popular there. Yeah, large wheels make the brakes look small but I don't think most people are limited rear brake, it's normally the tires and front brakes.

Your issue doesn't sound like the master cylinder since pumping does nothing. I think there's a spring on the outside of the caliper near the e brake? Also, maybe some fluid boiled off and there's an air bubble is in the ABS module? If you used the vagcom to pump the ABS while bleeding the system, it could make a difference.