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  #16  
Old 09-15-2001, 06:58 PM
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note: my two messages constitute one message. I don't know how, but the first one got cut off. Thanks

Alex

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1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
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  #17  
Old 09-24-2001, 01:08 PM
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The holes in the brake pads are bigger than the guide pins. There are supposed to be retainer springs under the guide pins that help hold the pads in place.

You may be having a normal noise. I get a certain amount of brake clunk on my '82 300D that I've just learned to ignore.

I doubt if you could bolt the calipers to the hubs improperly except for the possibility that they are not tight.

In my recent brake job, I found that the new replacement ATE pads swept a larger rotor area than the old pads, resulting in a longer wear-in period while the new pads scraped down rust. The next time the pads wear out I'm going to replace the rotors, pads and try a caliper rebuild kit.

Ken
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  #18  
Old 09-24-2001, 02:20 PM
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Lightbulb clunk??

You never indicated if you have the clunk on only one side or both!? You say that you just replaced the wheel bearings, brake disks and pads, and that you didnt have the noise prior to this. then the noise must be (usually is) related to work just done (as previous reply said).

I have done a lot of brake work on my 85 300D and I have never had brake pads clunk...even though there must be enough play between caliper and pads to slide the pads in. Also, I have put back old rusty retainer pins, and have not had a problem. So I dont think it is the pads, unless there is a LOT of play between caliper and pads. I would check this just the same.

Cant be the calipers shifting, as your previous posts indicate.

When you did the disks...you must have torqued the bolts properly...very tightly attaching the disk to the hub..so it is probably not the disks.

Wheel bearings....I think this may be related to your problem (not likely, but may be)...the nut holding the wheel onto the spindle may be a little loose...It is unlikely that this is the case as you would probably hear rattling over bumps in road...nevertheless, I have had the situation where, after installing wheel bearings, you tighten down on the wheel retainer nut to the point where it is appropriately tight, only to find that the bearings would then find their "proper seat", requiring a little more tightening of the retainer nut. What I would do is jack up front end and re-tighten the retaining nuts while spinning/wobbling the wheel. Tighten snugly, then back off 1/4 to 1/2 turn, then do final check to make sure there is no play when wobbling the wheel, and make sure the nut is loose enough to allow wheel to freely rotate.

Unlikely to be the strut rod bushings as there was no noise before you did the work.

The last, and perhaps most likely, possibility (and I know from first hand experience with "funny noises just after doing repairs") is that you may have left a screwdriver or wrench socket in the engine compartment...most likely rolled down in front of the wheel hump.

good luck!!

Mark
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  #19  
Old 09-24-2001, 02:41 PM
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one more thing...about strut rod bushings

If the strut rod (brake rod) bushings are bad, they are very easy to replace yourself, BUT you absolutely need spring compressor.....not the cheapo types that attach to the exterior of the spring...but the special tool that fits down through the hole at the top of the spring from inside of the engine compartment, and you slide a plate into the side of the spring catching the end of the retainer. Rent one from Performance(IPD) for $80....this turns the impossible job into a very simple one. If you dont have the correct tool, do not fool with this main spring!!! it is a potential killer!!

On a 300D the strut rod bushing is located on the lower control arm, under the steel plate that is attached to the lower control arm and holds the bottom of the main coil spring. (The strut rod is the rod that extends from this point back toward the rear of the car, attaching to the strut rod mounts at the foot wells.

To replace, jack up car, compress spring, remove plate that holds spring (three 13mm bolts). Remove main bolt that extends through the lower control arm, holding the strut rod. then swing the wheel/lower control arm forward, disassemble, and replace bushing...very easy self explanatory. One possible hitch....when I did mine the bolt on one of the mounts practically fell out, and on the other, I needed a propane torch, rust penetrant and more than 100 smacks with a hammer to remove...even after removing the nut and I could barely turn the bolt with a wrench, I still needed to beat it 50 more times to get it out!!!! The non threaded portion of this bolt is sized to fit very tightly into the hole in the lower control arm.

Good luck
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  #20  
Old 09-24-2001, 06:18 PM
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Wow, thanks so much for all the detailed info. The clunking happens on both sides, both on the first "brake" in reverse, and the first "brake" going forwards. The one going in reverse is slightly more "violent" (although it's not really really that loud) than the one going forwards which sounds like more of a gentle shifting. I have to take a closer look at the pads in the caliper housing but everything seemed to be ok (by visual inspection).

I suppose it could be the bearings/hubs that are not seated correctly. I don't really get noticeable rattling while driving and the brakes don't shudder (as they would if the rotor wobbled), but I guess it can't hurt to readjust the hub spindle nut (or whatever that's called).

Oh, and as for the missing tool theory, all of my tools are present and accounted for so unfortunetely it's not that.

Thanks for the ideas, I'll look into them as soon as I get my Landcruiser out of the garage.

Alex
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2012 VW Sportwagen TDI Manual
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  #21  
Old 09-24-2001, 09:24 PM
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Alex:

I've been reading this thread with great interest as I have a very similar problem with my Volvo 740 turbodiesel -- a distint thump when the brakes are applied. Mine is only when going forward, though, and my strut rod (also called a track rod!) bushings are new. The other end of the track rod also has a bushing, and these can go bad, too, allowing the end of the rod to slide between two positions -- a thump when it moves back, where it stays, then a thump when you pull hard enough by braking going backward to pull it back the other way.

The control arm bushing on the inner end could be bad, too -- check the rubber for deterioration. You might not be able to move it by hand.

If the wheel bearings were loose enough to make a thump, the car would wander. I don't think it is possible to have a rotor loose enough to thump that wouldn't wobble like crazy, but that is easy to check. If you can shake it with the pads retracted, it's loose.

One other thing to check, although it isn't obvious, is sway bar bushings, both where it attaches to the control arm (up top on yours, I think) and the body mount bushings. Usually makes a rattling thump when one wheel hits a bump, but could be moving only when braking, too, I suppose. Big pain in the ass on you car, easy on mine (I think).

let us know when you find out what this is!

Peter

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