Knock/Pop When I Brake - Page 4

Got Bearings? · April 4th, 2012, 11:25

Quote:

Originally Posted by Jettascuba

but can the caliper really move to and fro with the pads on? Yes, I know it moves slightly when applying brakes, but most of the time it is fairly tight, kept as such by the piston. Also can't see how it can make a clunk.

When bushings wear out, any bushings, what happens?

Airstream · April 4th, 2012, 19:48

Hey I would love it, if it was just that. Thanks for the diagram and description. I too am a little skeptical, but I am an amateur at best.

Would the torque on the bolts have any significance on the floating of the caliper? Could that at least be a test? Just trying to think of a way not to throw money at a mystery problem...

DPM · April 4th, 2012, 23:53

Strip and inspect. See if the pads can rotate loosely along with the disc- which would imply wrong pads or failed anti-rattle hardware. Then remove the pads and re-mount the caliper. It should slide smoothly in-and-out but should have no looseness in other directions. Torque on the pins isn't critical, tho.

Airstream · April 9th, 2012, 09:46

The brakes may be it, but since I have already dissassembled those once I want to revisit BlownBusa's suggestion/experience. I am now suspecting the trans mount. I just went out and grabbed the vacuum pump and the engine was easily moved back and forth. But there should be some play in it correct?
Here is a video of me trying to move it by hand from the vacuum pump (yes someone else is holding camera):

http://www.youtube.com/watch?feature...&v=1fMzP_iZ-Bc

I don't know when this mount was replaced if ever. The dogbone looked VW original. The squeaky noise you hear I often hear when costing in to a stop. In all honesty the clunk seems too big for brakes and like the engine/trans is moving forward. The clunk is proportional to stopping force. So quick stop = louder clunk. But again, I can only get one clunk per stopping event. Pumping the brakes never gets repeated clunks.

Open to critiques, don't want to wast another 60 bucks.

Airstream · April 11th, 2012, 07:32

Anybody else have an opinion?

Shawnz · April 11th, 2012, 20:26

This thread has talked me into replacing both mounts on my car to eliminate this same symptom on my car. I like that replacing the mounts will not be terribly expensive either.

Jettascuba · April 11th, 2012, 23:56

Quote:

Originally Posted by Airstream

I don't know when this mount was replaced if ever. The dogbone looked VW original. The squeaky noise you hear I often hear when costing in to a stop. In all honesty the clunk seems too big for brakes and like the engine/trans is moving forward. The clunk is proportional to stopping force. So quick stop = louder clunk. But again, I can only get one clunk per stopping event. Pumping the brakes never gets repeated clunks.

Open to critiques, don't want to wast another 60 bucks.

Well, now that my TDI is running again, I am waiting in anticipation for you to solve your problem as I have the same issue... LCA bushings had been replaced a while ago, dogbone is 10 years and 360 000km old though... and I simply cannot find the problem.

Airstream · April 20th, 2012, 07:47

Well I am probably going to take a break from chasing this down for a while. I am throwing money at a phantom problem. A number of days ago I took off the front bumper cover and saw that in fact like JettaScuba suggested that from radiator was out of the low mounts, just hanging there. Fortunately it was fairly easy to put the radiator back in the mounts and it is now much more secure. However that didn't fix anything.

So I went ahead and purchased a new tranny mount and installed that the other day. After a few trips I still have a clunk. It is better after doing the mount but it is still there. The main difference is I do not hear it as much anymore, so its not every braking event. This is probably due to either two things 1. forward momentum of the car has stiffened up so less force to clunk whatever it is. 2. It was the tranny mount and I didn't align it correctly on the install. I think #1 because I worked pretty hard to get it aligned but it may not have been perfect.

I am getting rather frustrated at the noise, it doesn't seem to affect anything, but the noise is taunting me. My next move before I leave the country in a few weeks will be to get slider pins and bushings. Easy and cheap thing to try. After that it can only be the brakes or the LCA bushings. (The later I have checked repeatedly) This is assuming all of the suspension work and parts installed by me are not doing it....maybe assuming alot.

constantine1.8t · June 19th, 2012, 08:27

Any updates with this? I fear I'm having the same issue, and when my lads/rotors have un-even wear the knocking is a lot more noticeable.

I've replaced the calipers and hardware so i know that's not the issue, as well as dog bone and upper strut bearings.

to note, when i hang a left at low or medium speed i get a creaking from the driver side. sounds like a strut bearing but those are only 10k old.

03CharcoalJettaTDI · June 19th, 2012, 19:22

I posted earlier in the thread with the same noise and I have noticed as well that I am also getting what I consider extreme tire wear on the very inisde of my tires.

At the begininng fo July I am replacing the LCA, shocks, struts and ball joints. We are hoping that this is the problem of the noise and will stop it and fix my tire wear. I will keep checking back in with you guys and let you know what happens.

constantine1.8t · June 25th, 2012, 08:46

keep us posted!

dcwilson · June 25th, 2012, 09:48

I have this same clunking sound since I bought my car over a year ago. It only happens when the brakes are cold though. Colder weather makes the clunk louder and louder. It comes from the from right wheel from what I can tell. Mainly happens when I back out of my driveway and hit the brakes. On a cool day, after 2-4 times braking the clunk goes away until the car sits over night and get cold again. Currently in the hot summer weather, there is no clunk. It's still a complete mystery to me..

constantine1.8t · June 25th, 2012, 12:07

that sounds like a loose/worn sway bar actually, check your bushings. had this happen to one of my Jetta's

I'm getting a creaking when turning the wheel left and the noise originates from the drivers side wheel. the sound is particularly dominant when turning at slow to no speed. (steering rack is new) and to note the steering is well influenced by the road.

Airstream · July 4th, 2012, 08:28

Sorry I have been out of the country for about two months. I have gotten home and the knock is still there. My next plan is to do the LCA bushings. My brother got in the car and thats the first thing he said it was. When I protested that they pass a visual examination he talked about how they can just lossen up over time without the bushing actually really ripping. Made sense. I also get a shudder when hitting the brakes which can the the LCA bushings from my understanding.

So thats my next move in about a month or so...

03CharcoalJettaTDI · July 10th, 2012, 18:06

Airstream listen up, this might help you, hoppefully.

As stated earlier in the thread I felt that I was hearing the exact same pop/knock noise as you and was also experiencing some inner tire wear, that I feel started alittle before I started to hear the noise. I talked to Paramdeick and he was almost positive that chaning out the shocks/struts, LCA's and ball joints would fix the problem. Well thats what he did this weekend and I have not noticed the noise since and I cant even begin to describe how much better a 140,000 mile car runs with all of this recently replaced. So if you have not checked/replaced some of these that might be where you want to start. I hope this helps you out.