I spoke too soon, brakes still FUBAR

DAMMIT!

Ok, here we go. Took her out yesterday for a healthier test drive (previous drive was

Reply to
"Doc"
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Doc. Have you checked your steel lines for corrosion holes anywhere. It could be sucking more air in as the fluid goes by.

Reply to
sidewinder

Have you checked your steel lines for corrosion holes anywhere. It could

I believe this would be very unlikely to happen because these lines can have hundreds of PSI pressure on them.

I have thought about this one for some time. In the days of front and rear drums master cylinders had a residual pressure valve at the Master Cylinder outlet. This was to keep the wheel cylinder under a slight pressure to keep them from sucking air. I don't know how it could happen but could the brake lines to the Mstr Cyl been switched. Most Mstr Cyl have different threads for front and back but not all. I wonder if the fronts being locked up without pedal pressure is due to the residual valve that is/was intended for the rear drums and the rear drums are sucking air because of the lack of residual pressure? If that is not the case it must be the combination valve

Reply to
Dan Calhoun

Ohhhh Doc....

Man oh man I hope Mystique never gets to actin' this way with me!

I'll tell ya what to try, if for no other reason than to make you feel a bit better...

  • Throw more beer cans.
  • Drive a POS car. Park your truck where it can see you doing this and when it sees the piece of junk you're driving in, it should scare the truck into stopping on a dime.
  • Hit the brake parts with a really big hammer.
  • Don't take it too seriously...you'll probably end up solving it when you least expect to do so...and when you don't happen to be thinking about it either.

I can kinda see where you are coming from on this. I'm trying to solve a never ending brake leak on the rear brakes...my ol' GMC is being really uncooperative at the moment...I hope it's an easy fix...but the lines at least are believed to be good. Gotta get some more new tires too...and somebody has really cranked the wheel nuts on there too. What fun.

Let us know how it turns out when you finally beat those brakes into submission!

William

Reply to
William R. Walsh

I'm not sure if your bleeding with the pedal or using a suction tool like a MityVac. I think bleeding by operating the pedal is probably better in this situation. And not with the bleeder open and the hose imersed but by opening the bleeder and shutting it as the pedal is operated. I know this takes two people though, but it can dislodge stubborn air. b

Reply to
Battleax

This is probably not related but it comes to mind. A guy at work told me of such a problem that he had and it came after he had replaced his master cylinder. Anyway after a pile of hair pulling and another master cylinder it turns out that there are some O-Rings that need to be changed that weren't and they are either inside or underneath (wish I'da paid more attention). Anyway, he took the master sylinder off again and replaced the O-Rings and all is OK now.

I asked the obvious. Why would the O-Rings leak air and not brake fluid and he didn't have an answer.

Probably not related. Just a thought.

-- Regards Gordie

Reply to
The Nolalu Barn Owl

Do I remember you saying that combo valve was leaking at the nipple a while back? maybe air is sucking in through there getting to the rears...?

Reply to
Scott M

Im just catching up to your problem so I dont know all the details, BUT. Hows the truck running, does it sound like it has a Vacuum leak (Power brake booster could be shot). Or you could have some rust under the bleeder valve preventing an air tight seal, Look for rust on the face of the bleeder valve. How do the wheel cylinders look inside the drum, are they leaking? Is the master cylinder the type with the plastic resevoir? If so hows it look. You have an air leak somewhere, bleeding it out with multiple gallons of brake fluid is not going to help untill you find the leak and seal it. Good luck and dont throw a wrench thru the windshield (it wont do you any good but it will make you feel better)

Reply to
seeray

Reply to
seeray

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