Brakes need to be pumped

Hi,

I've got a 1977 Civic with brake problems. I burnt out a wheel bearing, and
when the wheel wobbled it opened up the front brake calipers. You then had
to pump the brake pedal to narrow the pad to disc gap, and get brake
pressure again.

I put a kit through the master cylinder and replaced the wheel bearing. I
noticed when replacing the knuckle that the new wheel bearing seemed very
loose like the old bunky one, but once I tightened up the CV joint it all
seemed to firm up.

Now the brakes are worse than before. If I go around a turn or a bend, then
I lose brake pressure, and the pedal goes to the floor. I'm not losing
fluid, though. I get brake pressure back after a few pumps of the pedal.

Any suggestions anyone?

Murray R. Van Luyn.

 

My first instinct is that you should not have messed with the master
cylinder when you knew the problem involved probable damage to the wheel
caliper. Your symptom sounds like either a bad master cylinder or air in
the lines.

First check that the system is completely air free. Do a complete bleeding
according to the sequence in the shop manual. Then check that the suspect
wheel caliper in fact works correctly, or maybe just replace it to be safe.

If it still has problems after that, then the most likely suspect is that
the master cylinder did not survive the rebuild attempt and should be
replaced.

 

Hi E,

Yeah, the sequence was
1. replace master cylinder - replacement couldn't be primed, so was
discarded.
2. rebuild old master cylinder and refit - no change.
3. replace wheel bearing - problem much worse.
4. Bleed entire brake system per shop manual - no change. Pedal still
reaching floor after turns or curves.

I'm going to change the front right knuckle, bearing, disc and hub assembly.
I didn't like how loose the replacement with the new bearing was before the
CV was done up. It felt all sloppy like it was with the old bearing, but
feels quite solid now that it's fitted. I should have looked into the
sloppiness of the new bearing before I refitted the knuckle. It's quite
possible that I had the wrong bearing, and the blokes that pressed it in
couldn't give a rats.

If that doesn't fix it, then I'm stumped. It's definitely front disc
calipers openning up around corners and bends. You have to pump the brake
pedal to close the gap before you get a solid response.

How does that sound E. Am I going about it the right way this time?

Regards,
Murray R. Van Luyn.

 

Get somebody (else) to check the runout on that disk after its all done &
that should tell you definitively if there is any problem still at that
wheel. Probably a good idea to get a different set of eyes to go over it
all.

 

then you're chasing the wrong problem. #'s 1, 2 & 3 already told you that.

dude, you're wasting time, money and much more importantly, endangering
other road users doing what you're doing. you don't have a proper
diagnosis, so STOP fucking about.

sorry to be so blunt, but that's the truth. NEVER **** with an
automotive system you don't completely understand. especially not when
it involves the brakes.

1. right now, tow this vehicle to a pro and have them sort out your mess.

2. if you still want to **** with this vehicle in the future, sign up
for evening classes at your local community college and learn how to do
things properly while under "adult supervision".

3. learn something very important: DO NOT KEEP THROWING PARTS AT A
PROBLEM IF YOU DON'T HAVE A PROPER DIAGNOSIS!!!!

 

I'll do the knuckle, 'cause the cost is just time. I have a mildly worn
spare that will do, and it's all about losing pressure going around corners.
If that doesn't do it then it's time for a professional diagnosis I guess.

Yes, I acknowlege that brakes are a very dangerous thing if you don't get
them right. That's why I prefer do the work myself, rather than let some
grubby, time pressed ape stuff about with them.

Thanks very much for your invaluable advice E. I appreciate you letting me
bounce that one off you.

Regards,
Murray R. Van Luyn.

 

With the road wheel off the ground, supported under the lower control arm,
grab the top and bottom of the road wheel at 12:00 and 6:00 positions. Is
there play when you rock the wheel in and out?

Now have a helper step hard on the brake and hold it. Perform the same
rocking action. Is there play now?

If play disappears when the brake is pressed and held, the bearing is
loose. If the play is still present with brake held, something else is
loose.

 

Hi Tegger,

Thanks very much for the input on this one.

The curious part is that tightening up the CV joint makes an otherwise loose
(as buggery) bearing tighten up. I found no discernible play with the wheel
on the ground, or jacked up off the ground!

Anyway, I've replaced the knuckle, bearing, disc and hub, and I now have
full, unwavering, delicious brake pressure again. My wonderful 31 year old
Honda is once again a delightful pleasure to drive.

Thanks again for all the help and reminders guys. I really appreciate it.


Regards,
Murray R. Van Luyn.

 

next time, why not replace the whole car? saves all the tiresome effort
of spending money not figuring out the problem.