91 Accord - Brake Problem

I seem to be having trouble with my brakes. I think that the power booster
pushrod is pressing against the master cylinder and causing the brakes to
drag ever so slightly. At high speeds, the rotors heat up, causing the
steering wheel to shake. After a short while, you then begin to smell the
brake pads and you can feel the heat off the rotors. Is there a special
procedure to adjust the booster pushrod? I can't seem to get it to change
its position in relation to the booster. I've had the booster off the car
and moved the adjuster nut on the back of the booster, which I thought would
change the relation of the pushrod, but it has not made any difference.
When the master cylinder is attached to the booster, there should be
clearance between the pushrod and master cylinder piston (1/32 in.) I'm
going crazy with this problem.....any help is appreciated. Joe

 

That seems to be the procedure Haynes describes (although they call for
measurement of the depth of the master cylinder piston mating surface
compared to the measurement of the pushrod from the surface, and specify 0
to 0.016 inches). Are you able to tell if the adjustment does anything at
all?

Mike

 

Thanks for the reply. As I tried to make the adjustment, I used a straight
edge and a 6 in. scale to measure the end of the pushrod from the face of
the booster. After adjusting the rod, I saw no change in the position of
the pushrod. I am really stumped. Since I left the locking star nut loose,
I guess I will try moving the rod to one extreme and then the other.
Moving the position of the rod is suppose to change the position of the
pushrod. Maybe by trial and error I will figure it out. Thanks again. Joe

 

How do you know this? A mis-adjusted pushrod generally makes the brakes
stick on a little more each time you step on the pedal, until the car is
immobile.

Your caliper pistons are likely sticking on account of gum and rust on the
piston, causing the pads to drag on the rotor. Pull the brakes apart and
check.

Your slide pins and pads are probably sticking as well.

http://www.tegger.com/hondafaq/Brakes.html#troubleshooting
http://www.tegger.com/hondafaq/rustybrakes/brakes1.html

 

Joe.
It is possible that you are "barking up the wrong tree".
Every time that I had the symptoms that you describe, (over heated
rotors, steering wheel shake at highway speed, smell of burnt rubber)
it turned out to be defective/binding calipers, they were binding
because rust would build-up on the caliper in the area just behind the
dust boot.
My fix was to either rebuild/clean the calipers -if rebuild kits were
available, or replace them with rebuilt units.
HTH
JerryR

 

The calipers are rebuilt....both sides. I replaced the flexible brake
lines, thinking that they may have been collapsed. Still the same problem.
If I put the car in neutral, it should roll freely, but it doesn't. I need
to make an adjustment to the pushrod, but I'm not sure how. Thank you, Joe

 

It does seem like the problem gets worse, the longer you drive the car. I
thought that it was because the longer the car was drive, the more heat was
generated by the brake pressure against the rotors. The calipers are
rebuilt....one only a few days old. The slide pins are clean and well
lubricated. I need to determine how to adjust the pushrod......which I
believe to be the problem. The master cylinder is a rebuilt too. Thanks
for the reply, Joe

 

For the Civic/Integra:

Back the pushrod in until the brakes do not lock on. Adjustment is done at
the "star" locknut against the booster, NOT the locknut against the clevis
that attaches to the pedal!

Accord may be the same.

 

I had a similar problem on my 91 Accord DX. It turned out to be the
brake pads binding on the calipers as the pad backing rusted a little.
I took the pads off and hit the edges that slide on the caliper with
emery paper. It did the trick! But then less than a year later the
problem returned. I took them off again and used a file to remove the
rust and just a little metal so it wont happen anytime soon. It's
been over a year now and it hasn't happened again.

If you have had this problem for any length of time or it has been
very bad ("begin to smell the brake pads") the rotors may be heat
damaged.

 

---------------------------

MANY years ago I had a Volvo 122S that did exactly what you're
describing. The vacuum assist was activating, and the front disks would
get HOT! Tried to pass on the highway and suddenly started to go
SLooowwwer. Got out and made the mistake of touching the disk. I heard
it before I felt it. Sizzle. It was - 40 at the time, but it was
troublesome all that winter. Finally adjusted the rod inside and fixed it.

The Volvo had an excuse (it was a #%$&! Volvo)

'Curly'