after alot of hard breaking once, my right rear caliper started sticking and when i would let it roll in neurtral you would feel it breaking and the car would not roll as far. i tried pushing it form a stop in neutral and it required alot fo extra force and when i got back from that fast drive with lots of breaking it smelled like burned clutch from that break.

i left it hoping it would be fine in the morning(maybe a temperature thing) but no it was still fucked

so i took the calipers apart and put them back together and it worked fine after that!

to me it sounds like that caliper is not working right and replacing it might make it move smoothly liek the rest, but wait to see what other members think!

 

Well, I had removed it and reinstalled it once this weekend, the condition likely existed before the new pads, and exists after the new pads. Plus, I've greased the caliper bolts and applied a light grease where the pads and caliper ride on the carrier, after a thorough wire brushing.

Given that the piston was hard to move back into its bore, I suspect it's the piston. I could rebuild it myself, but the price of a rebuilt caliper isn't exhorbitant.

 

I am getting a strange smell from my RF wheel after my commute home much like a burning plastic type smell and I am wondering if something is going on there with the brakes too....any idea? Should I wait another 2000 km until my regular maintenance service or take it in now? I do not notice any noise or any other braking problems.....almost smell like a burning electrical wire but it is definately coming from the wheel well.

TIA

 

I am getting a strange smell from my RF wheel after my commute home much like a burning plastic type smell and I am wondering if something is going on there with the brakes too....any idea? Should I wait another 2000 km until my regular maintenance service or take it in now? I do not notice any noise or any other braking problems.....almost smell like a burning electrical wire but it is definately coming from the wheel well.

TIA

mine smelled very similar to a clutch burning up, not plastic like. it was from the wheel and the rim was noticablly hotter than the other rims.

i relieved the problem by take the caliper and rotor off and putting it back toghether and it worked fine

jack the front of your car up put it in neutral and see if you feel a difference in the front right and front left rotating, if you notice the front right is harder to turn its probably touching the rotor

if you have a standard you will know right away if its breaking by letting it roll in neutral alittle and if you feel resistance you didnt feel before its sticking!

 

Ok, now I'm stumped here.I've replaced the passenger side caliper, as it seemed obvious enough to me that the caliper on that side was stiff. Or so I thought....
No luck. That corner still gets hot (rotor temp closest to the hub hit 205 degrees, and pad temp was 180, vs 140 on the other side on my drive home from work today.)
That side is making a little bit of a noise as the corner gets hot- sort of a quiet rythmic thrumming from that corner when that corner heats up.
So... the fluid is replaced, the caliper (and caliper carrier) have been replaced and are sufficiently greased. Not sure what to make of all this.

The car doesn't pull in any particular direction- tracks laser-beam straight. So... something fishy is definetely going on.

 

Bumping this up- maybe one of you VW techs out there have any hints.

 

You replaced the caliper and the carrier - what about the bushings? The rubber bushings are crap and can cause 'caliper dragging' symptoms. Tyrolsport bronze bushings would be a good replacement:

Tyrolsport Brake Caliper Bushing Install & Review
New braking product that you guys might be interested in....

 

You replaced the caliper and the carrier - what about the bushings? The rubber bushings are crap and can cause 'caliper dragging' symptoms. Tyrolsport bronze bushings would be a good replacement:

Tyrolsport Brake Caliper Bushing Install & Review
New braking product that you guys might be interested in....

The bushings on the replacement caliper are new and very well greased, and the rebuilt caliper came with a new carrier. It floats well, no signs of binding The only thing I reused were the brand new pads and the outer anti-rattle spring. The old pads on that side had worn prematurely, so I don't think it's a pad problem.

Is it possible that a bad bearing could be causing this problem? That thrumming sound is making me think bearing, though the steering knuckle doesn't seem to be particularly hot. I don't notice any slop in the wheel, though.

 

Hmmm... You have a nasty-sounding issue one there...

When you did your pads, did you check the rotors for runout? If that sucker was really warped, I suppose that could cause strange issues.

Even if you have a bad bearing, I can't see how the heat would migrate to that degree from the bearing to the brake pads.

Maybe your ABS controller is acting funny, braking that wheel when it shouldn't? (You don't need to touch the brake pedal to activate ABS... that is how ASR works) Grasping at staws here...

SirWired

 

Today I drove the car to work with a minimal amount of braking- did most of my slowing down with downshifting/coasting and at slow enough speeds, some e-brake.

Brake temperatures were elevated on the bad corner, but well below the temps I've been seeing. (140 deg vs 100deg) Also, the thrumming wasn't happening.

Here's a theory:

When I apply the brakes, the caliper on that side is somehow slower to fully release. It doesn't drag enough to slow the car down noticeably, but it drags enough to rub the pad on the rotor and create extra friction. With more braking, there's more of this "extra friction" because of the slow release. If the hose is damaged internally and acting as a check valve, its possible that the problem gets worse as the brake heats up, as the fluid will thermally expand and create extra pressure that can't relieve itself by traveling back to the master.

The rotors are brand new, and the problem was occuring with the old rotors too. So I'm ruling those out. Also, there's no appreciable pedal pulsing, so the rotor isn't warped. The caliper is a new rebuild, and the bushings are new and well greased- good float on the caliper in testing. I'm also ruling out the bearing fow now, as the hub carrier is not as hot as the rest of the brake. It may, however, shorten the bearing life on that corner. The ABS controller has no codes stored, though at some point I may drive it with a vag-com hooked up and record some data.

What I may do is raise the corner, press hard on the brake, and see how freely the wheel turns after release. This will tell me if pressure is being released when the pedal is lifted.

 

V6 or 1.8T?

If 1.8T, isn't the turbo right there near that wheel housing? I remember that after a hot autocross run in my 1.8T I could feel hot air coming off the RF when checking my tire wear and pressures. I noticed that this wasn't the case on the LF. That might contribute some to the heat differential.

 

It's V6.

That wheel is also slightly dustier, makes noise when hot, and my fuel economy has declined about 10%. The old pair of pads on that side wore excessively, also.

 

ctobio, Did you ever resolve this problem????

They did my cam adjuster covers as they were leaking but I still seem to have the burning smell! I am at a loss. I have to take it in for the 64000km service in a few weeks so I will have them look at it again. I think I'll also get a temp reading of my disks like you did....

 

You replaced the caliper and the carrier - what about the bushings? The rubber bushings are crap and can cause 'caliper dragging' symptoms. Tyrolsport bronze bushings would be a good replacement:

Tyrolsport Brake Caliper Bushing Install & Review
New braking product that you guys might be interested in....

Don't do this in if you live in a place like the Northeast which has rough winters. The Tyrolsport bushings need regular manitenance as the salt and sand from the winter is very hard on them. I learned the hard way.

 

Don't do this in if you live in a place like the Northeast which has rough winters. The Tyrolsport bushings need regular manitenance as the salt and sand from the winter is very hard on them. I learned the hard way.

So there is no boot?

 

Weird issue. I think it is still a piston related issue. How did the piston on the new caliper retract? Was it as easy as the piston on the working side? Perhaps the piston on the new caliper is a little stiff.

I just redid my rear brakes (rotor/pad/fluid) and after a couple of days the driver rear caliper started to drag and cause the temp differential that you are seeing. I must have pushed some crap back with the piston when I retracted it.

 

Victory!

I think.

Did I really start having this problem 2 years ago without a fix?

Anyway, 30,000 miles after replacing the caliper and pads, the pad on the affected corner finally wore out, so I decided to change it, bleed my hydraulics, and change the hose. Here's what I observed:

When I bled that corner (before replacing the hose) today, it took 45 minutes to get 300ml of fluid out that corner, where the other corners took 5-7 minutes for the same. Sounds like a clog of some sort.

I replaced the hose, and then re-bled that corner. This time, it took about the same amount of time to bleed out that corner as the rest.

After some braking to bed-in the pads, the temperature differential at the corners is inline with expectations- within a few degrees of each other. I'm pretty sure once the pads are fully broken in, I should be seeing everything back to normal, and clean wheels at last with the PBR Deluxes I installed all-around.

I'll probably dissect that hose and see what was wrong with it.

 

Thanks for the follow up! Nice work. This will be helpful to many i'm sure.

 

I hate to admit it, but I've been having the same issue on my car for at least the last six months. It's gotten to the point where the rotor is definitely warped and I'm getting a similar sound that I was beginning to think was the wheel bearing. I will inspect the hose carefully when I change everything out. Thank you for sharing ctobio!

 

The test is to see how quickly that corner bleeds out, I'd say. If it takes longer than the other corners, there's a restriction somewhere in the hose.

 

Dragging Caliper Ditto

I'll throw my hat in here and bump this thread for advice.

I've had the same issue with my front left and to a lesser extent the right rear. After perusing this fine forum and thinking I was a clever Passatworld reader, I first lubed up my sliders, then changed the caliper (inlcuding bracket and sliders) and then changed the hose. Just as ctobio has.
No difference, the issue is still there.
I don't know if this is important or not, but each time after completing one of these fixes, the post-op test drive appears to be fine. I go to bed happy that I figured it out.
But then its after driving to work the next morning (15 minutes, mixed highway and stoplights), that I notice that front caliper is hot hot hot. Its like the caliper gripped the rotor overnight and then drags the next morning. ?

I used an IR temp gauge as well- rotor temps after 15 minute drive are:
FL: 400
FR: 150
RR: 200
RL 150

So if its not my caliper or hose... what's next? Master cylinder? Vacuum assist pump? ABS?
I'm not getting any CEL with this issue- is there anything i can look at with VAG-COM?

Is there a way to disconnect the the vacuum assist pump perhaps, and see if the caliper is still dragging? (I would have to be Mr Strongfoot on the brake pedal, yes) This might indicate the problem is hydraulic?

Thanks for any advice.

Car is an 02 wagon 1.8T FWD.

 

The fact that the issue is on diagonal corners (FL, RR) tells me that one of the circuits of your master cylinder is experiencing a problem.

The master cylinder consists of two independent hydraulic circuits. What is possibly happening is that one of the pistons in the master cylinder is slow to retract. It is also possible that one of the braided lines coming out of the master cylinder has failed internally.

Check out this page for the theory of how the dual-circuit master cylinder works:

http://auto.howstuffworks.com/master-brake1.htm

The vacuum booster will not be the problem.

Have you done the bleed test?

 

x2.

on fwd vehicles, diagonal wheels are on the same circuits.

on rwd vehicles, they use rear on one circuit and front on the other

on awd, i believe they may follow the rwd method, but varies per manufacturer.

btw, does anyone know if that company rusty posted about above is still in business?
it's worth it to check out.

 

Thanks for the reply.
Makes sense- i didn't know about the diagonal connection.

I did a bleed comparison on both front wheels. I used the Motive power bleeder set at 15 psi, and compared the flow rates at the bleed valve. I didn't see a noticable difference. Do you think this indicates the lines are not constricted... confirming the master cylinder as the culprit? The front left brake appears to come from the secondary chamber, if that makes any difference.
There are no flexible brake lines on the front other than the hose at the wheel, and they all look clean and solid, at least from the outside. With the FL hose replaced, i'm thinking i can rule out that issue.
I also have ABS, which is new to me, so I'm not sure if an ABS unit can fail this way. There's no pulsing or anything- the caliper just won't let go.

So... master cylinder... any tricks at replacing this one? I did one on my jetta years ago, but i don't think it was very fun. This one is decidedly less corroded (not at all) than my old jetta, so perhaps it is not so difficult?
thanks-

 

vacuum boost code

The plot thickens- I was close to ordering a new master cylinder, but have been taking my time to make sure that's it.
I have no check engine light in the car, but decided to run a scan anyway, just for fun. lo and behold,

2 Faults Found:
17887 - Brake Boost Vacuum System: Mechanical Failure
P1479 - 008 - Implausible Signal
16502 - Shareware Version. To Decode all DTCs
P0118 - 002 - Please Register/Activate

looks like P0118 is called "Engine Coolant Temp.Circ High Input", which doesn't seem like it has anything to do with the brakes.

First, i don't understand why this code is lurking in my car without a proper CEL telling me its there. But beyond that, I am now suspicious of brake booster. Anybody know of a means to test this pump?
I will look over the vacuum lines for leaks, but would a leak be causing the calipers to drag?

Or is it the other way around, the master cylinder is actually at fault, and the pump is throwing a code because the MC isn't cooperating?
thanks for any comments-

 

The plot thickens- I was close to ordering a new master cylinder, but have been taking my time to make sure that's it.
I have no check engine light in the car, but decided to run a scan anyway, just for fun. lo and behold,

2 Faults Found:
17887 - Brake Boost Vacuum System: Mechanical Failure
P1479 - 008 - Implausible Signal
16502 - Shareware Version. To Decode all DTCs
P0118 - 002 - Please Register/Activate

looks like P0118 is called "Engine Coolant Temp.Circ High Input", which doesn't seem like it has anything to do with the brakes.

First, i don't understand why this code is lurking in my car without a proper CEL telling me its there. But beyond that, I am now suspicious of brake booster. Anybody know of a means to test this pump?
I will look over the vacuum lines for leaks, but would a leak be causing the calipers to drag?

Or is it the other way around, the master cylinder is actually at fault, and the pump is throwing a code because the MC isn't cooperating?
thanks for any comments-

what you have is a vacuum leak. i got the same code when i accidentally had wires backwards on my v6.

pull the thick hose off of the brake booster, and with the car running, stick your thumb over it. if it sucks your finger pretty well, and you have no brake booster activity (it's a hard pedal most of the time, and brakes seem weak) then you have a bad brake booster.
your master cylinder is not at fault, the MC is the silver thing bolted on to the big black tin in the engine bay, behind the firewall.

if you are replacing the brake booster, you can leave the master cylinder hooked to the hoses, and remove the brake booster without bleeding or removing any fluid.