Important note on Brake Bleeding

[g.frost]

Hello All, getting ready to do my rear drums and searching through old threads for any tips...... This one is seldom mentioned but worth repeating::
(Oldblueaccord mentioned a couple times I found)


When bleeding brakes, never push the pedal down more than an inch or two.
Instead of pushing the pedal near or to the floor, just pump them repeatedly and only push down about as far as your normal pedal movement to stop the car.... WHY? (unless you plan on replacing the master cylinder....)

After many years of use, the master cylinder will have a bit of crud coating the inside where the piston has never traveled. When you pump the pedal lower to the floor, the seals will wipe through this crud and when you are done it will soon be time to replace or rebuild your master cylinder!

If your brake pedal sinks slowly to the floor when stopped and applying pressure (and there are no external leaks in the brake system) it's likely the master cylinder seals leaking back into the reservoir.

I have seen this problem caused by pumping the pedal far too many times on many different types of cars and by trained mechanics who should know better too. Save yourself the trouble and expense next time you bleed the
brakes.

OK, my contribution to the board today and thanks to everyone for all the great tips I have read here to keep my old cream puff beater on the road

[russiankid]

On this note, can't you just flush out the system and get all the crud out of there. I know when i changed my brake fluid i ran clean brake fluid on each side before i closed it off.

[g.frost]

Once the crud gets swiped up by the piston seals it has a way of sticking to the seals and is hard to get out of there without rebuilding. Sometimes the problem will show up right away, sometimes a week later or it will be intermittant for a few weeks. Sometimes there is no problem at all too. Anyway, flushing the brake fluid is always a good idea when doing the brakes. Just bleed the brakes with a pump or don't push that pedal too far down.... Well that's been my experience anyway. I've seen it happen on a number of different cars. "Just had the brakes done a couple weeks ago and now I need a new master cylinder? WTF?"

[russiankid]

I've been driving with this brake fluid for about 2 months now after i flushed it out by pushing new fluid in and old out. I pushed the pedal all the way to floor and i have no leaks(knock on wood).

[lostforawhile]

there shouldn't be crud in the master cyl. if you regularly flush out the old fluid. on another note,when you replace the master cyl,take off the resovoir cup of course,pop the screen cup out of the bottom, and wash the cup and screen with brake cleaner really really well.

[Jasonf860]

Buy a vacuum/pressure bleeder and forget that antiquated brake pumping BS. Besides, if your Master cylinder has crud in it, it's time to replace it anyway.

[g.frost]

After 20 years on the original master cylinder.... if it ain't broke....
I'm just doing the rear drums, shoes, and seals. The seals are so cheap and easy, it's a good idea to do them when doing the shoes. (Again, pushing the piston seal in over that old brake fluid "crud" can sometimes cause it to start leaking and make a mess of your new brake shoes.)

Only what needs fixed gets attention on this beater!

I'm in the mode of just keeping this thing (safely) on the road. 145K miles and last tank got 29.5 miles to the gallon around town.
This car has to be one of the cheapest cars to run!
Has been very low maintenance and paid off for 16 years, I owned it since new. No nice shiny wheels on this thing!

Anyway, I know of a 91 accord and 95 acura both had master cylinders replaced because of the above issue..... (shortly after the brake job.)
Working on older (and sometimes neglected ) cars these things become more of an issue. So pump the brakes to the floor at your own risk or get a bleed pump.