Brake lock-up

Thanks in advance as this has been a multi-month frustration point.

Issue:
Brakes will hold and not release regularly.

History:
About 3 months ago the car lost nearly all braking power - I went
through various checks and figured it was the brake booster. So I
replaced the brake booster. All was well for about a week when it
started - the brakes would engage and hold. I would have to power the
car to get to places. Went in and adjusted the brake push rod
connection so it would be higher.

This worked reasonably well for a while but it would still happen from
time to time and it became very frequent. Follow on problems was that
breaking would produce a significant shudder. So this weekend I
replaced the rotors and pads.

Car is on jacks in garage but when I put my foot on the brakes they
lock and hold. No way to move the wheels. Turn off the motor and after
a while they loosen a bit. Not alot as the new pads have the usual new
pad lack of clearance.

Your suggestions most appreciated.

Thanks,

-Robert

 

But did you adjust it CORRECTLY?

Brake pedal /height/ is not the same as pushrod /clearance/.

See here:
http://www.tegger.com/hondafaq/mastercylinderreplace/howworks.html

 

I suspect that I did NOT do it correctly and a quick glance at your
site looks very very promising as your explanation makes perfect sense
- with the cooling of the fluid (pressure = heat) it does seem to
release slightly.

I have been trying to play with the star nut as you advise but will
reread and re-cdouble my efforts. What I found was that the connection
to the pedal was in the way.

Again thanks and will report back how this turns out.

-Robert

 

Hi Tegger and Netizens,

First I want to thank you as your very useful URL got the job done:

There was one discrepancy however that I will pass on here - the
adjusting nut was in fact the key rather than the pushrod. The
explanation on the web pages emphasizes that you should not allow the
adjusting nut to turn.

I had the advantage in having my old booster out of the car already
and I played with it first and what I discoverd was that turning the
adjusting nut clockwise (close) resulted in the pushrod working its
way out. I also tried holding the adjusting nut in place (as
recommended in the link aboe) and turning the pushrod counterclockwise
(open) and it also brought the pushrod out. Turning the adjusting nut
counterclockwise brought the pushrod in.

So I loosened everything and turned the adjusting nut as it was worlds
easier. For some reason turning the pushroad was very difficult and to
be frank I did not have the time nor inclination to go the lengths you
did to create special tools. The pedal height incerased which was
fine and my lock up problem has ceased.

So bottom line is the issue appears to be fixed and your pages got me
to that state.

Thanks!

-Robert

 

I like good news. Thanks for the update.

Until you're /ready/ to turn it, that is.

The only way to adjust the pushrod freeplay is to turn the pushrod and
the Adjusting Nut, but if you allow those two to turn before you're
/ready/ to turn them, you will make it more difficult to effect the
corrections you desire.

In other words, allowing the pushrod and Adjusting Nut to turn before
their time, and allowing them to turn in an unrecorded manner,
effectively makes you shoot at a moving target.

The entire page depends upon the booster remaining in place /on/ the
car. If the booster is /off/ the car, the required technique is rather
different, as you have demonstrated.

The page I wrote was intended to help people overcome the limitations
imposed by the booster remaining /on/ the car. ON-car pushrod
adjustments are what the vast majority of owners will face.

And you didn't need to. Those special tools are meant to deal with the
very cramped room under the dashboard. Since your booster was off the
car, you would have had loads of room in which to frolic.

You're very welcome.

Even though the page didn't deal directly with your specific situation,
it still appears to have given you the kernel of information you needed
to solve your specific situation, which is the whole point of the entire
HondaFAQ site.

 

Again thanks - just a note for clarity. Certainly don't want to be
perceived as chippy just clear...

I had to adjust the pushrod / adjusting nut from underneath the dash
as your page depicted.

My good fortune was that the old booster was still around and I was
able to experiment on it prior to working on the new booster (the one
that needed adjustment and was in place within the car).

It was after experimenting on the old that I found that moving the
adjustment nut would do all I needed. Having discovered that I applied
that to the booster in place. The retrospective was that the
replacement booster I got had very similar instructions with it (but
they were badly written and caused me to doubt the message).

Again my sincere thanks,

-Robert

 

Rotating the adjustment nut changes the pedal height. Rotating the pushrod
ONLY and not allowing the adjustment nut to turn leaves the pedal height the
same.

Pedal height adjustment is a separate operation from freeplay. You have mixed
the two operations together.

As I say on the Website:
"The pedal height adjusting nut (opposite its locknut) is welded to the back
of the clevis, which is pinned to the pedal arm. If you use the 17mm wrench
to keep the Adjusting Nut from rotating while you turn the pushrod with a
pair of pliers, the distance between the pedal height nut and the Adjusting
Nut will not change, so the pedal height will be unchanged even as the free
play changes. The locknuts themselves will not alter any clearances."