Brake Problem & Floor Mats

["Al Powell" <APOWELL@agcom.tamu.edu>]

 From: Debu Purohit <purohit@haas.berkeley.edu>

> I'm running into a bizarre brake problem on my 1992 100S.
> The brakes groan very loudly when I step on them (sounds like
> a large truck is coming through).  However, this
> happens only when I'm reversing at slow speeds such as backing out 
> of my driveway or into a parking space.  I haven't been able to replicate
> the sound when I'm going forward.

BTSTDTGTS.  (Been There Seen That Done That Got The Shirt)

> The mechanic says that my rear pads and rotors have to be replaced.
> That part I knew.  However, he adds that there are lots of
> iron filings around the ABS sensor which are causing the
> ABS to kick in.  His rationale for the sound occurring only in reverse is that
> the metal filings have all lined up in one direction, because most
> of the driving occurs in that direction.
> Does this make sense? 

NO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!  He wants to get in your 
pocket and it sounds like he doesn't know this car.

>  (I have never felt
> the brake pedal pulse when I'm reversing at less than 5 mph.
> Although, I have to admit that I've never tried reversing at
> higher speeds.)  Anyway, the mechanic recommends changing the rotors
> and pads and cleaning out  the sensors to attempt to solve the problem. 
> Any thoughts (especially because he wants to charge $500)?

YES.  If the pads are not worn out, I bet YOU can fix this for about $3!!  
My 1990 200 was doing the same thing.  What's happening is that your 
worn pads are vibrating on the rotors when you back up and apply the 
brakes lightly.  All you need to do is pull the bottom bolt from the 
rear calipers, rotate them upward (leaving the pads in place) and 
lubricate the back of the brake pads with hi-temp grease designed 
specifically for disc brake pad applications.  Re-assemble, coat the 
bolt you removed lightly with medium grade Loctite, re-insert and 
torque to specs.  Total time per side: about 20 minutes.

I've heard more than one do this, usually when the pads are at least 
50% worn and the lube has had long enough to melt and run out.  In 
the short run (for the rest of the pads' life) a good layer of lube 
will dampen the vibration and eliminate the sound problem.

If the pads are truly worn out, you'll have to replace them and the 
rotors - but DO NOT pay $500!  You can buy the parts for this 
from Blaufergnugen for about $150, and the rest is labor.  The only 
difficult part of the job is turning the brake pistons back into the 
calipers, and I made a tool out of a large socket (Cost = $70 for the 
bench grinder I'd wanted but finally had an excuse to buy, hee, hee).
(Lessee....$150 = @4.71 qewsas, right Dave?)

Any competent mechanic can do this job for the parts cost plus NOT 
more than 2 hours labor.  With the correct brake tool to turn in the 
piston, it might be done in less than one hour!!

> From: feb@febsun.cmhnet.org

> A few times over the last six months or so, I've had my gas pedal
> get stuck beneath my driver's side floormat.
> It takes a really good tromp on the gas pedal to make it stick,
> and then when I lift my foot, the pedal is stuck down and doesn't lift.
> When this happens I experience *unintended acceleration*!

OK - you can make your own hooks to hold the mats in place.  Take a 
coat hanger and cut two 4" sections, then bend them into "S" hooks 
which actually look like a "Z". 

Take one side (hook) of the Z hook and stick it thru the carpet on the floor 
- use the other hook of the Z to snag the floor mat and hold it back 
from the pedal.  Many mats have loops of fabric on their back to hold 
these hooks...you could sew on some made of nylon fabric or even some 
nylon cord.  Position the mat where you want it - about 2" further 
away from the pedal.   Problem solved.

Al Powell                           Voice:  409/845-2807
Ag Communications                   Fax:    409/862-1202
107 Reed McDonald Bldg.             Email:  a-powell1@tamu.edu 
College Station, TX  77843-2112
W3 page - http://agcomwww.tamu.edu/agcom/satellit/rpe/alpage.htm
         "Illegitimati Non Carborundum" - Heinlein