Hello all,
Had a nice scare on the way to work today. I had an issue with this car when I first bought it and since changed the master cylinder. Bled the entire system, had a nice firm pedal and good braking after installing the new master cylinder. Today pedal to the floor again, and when this occurs my right front brake seems to be stuck against the rotor and burning the pads. This problem is scary to say the least. I am not losing fluid, and I can pump the pedal and get pressure to return to the system, where it will be fine again. Did I possibly get a bad master cylinder or is there something else I should be looking at?
Thanks...
Chuck Jaxel
Pine Hill NJ.
5 volvos and a Chevy...

Thanks for all the tips, looks like I need to go back and reexamine every thing in the brake system. I'll post back what I find. FWIW I believe the car had sat for some time before I purchased it, and yes it does have ABS. Fluid seem to flow ok through all bleeders, may just do a whole brake update with new calipers and rotors and hoses and start fresh, we'll see what the budget allows.
Thanks again.
Chuck Jaxel
Pine Hill NJ.
5 volvos and a Chevy...

I think '92 came with ABS, so you won't have the dual diagonal braking system. Probably a sticking caliper causing fluid boil. Pumping pedal may loosen caliper?
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1980 245 Canadian B21A with SU carb and M46 trans in Brampton, Ont.

When you bled the brakes did the fluid flow with pressure or dribble out? You should have a strong stream of fluid coming from all bleeders. If you are getting a dribble, suspect collapsed brake hoses.

Brake hoses should be changed prophylactically. As hoses age they tend to collapse in on themselves, like a diseased artery. You won't know it by looking at the outside of the hose. A collapsed hose can also cause your brakes to drag.

Loosing the pedal and getting it back again may be boiling fluid. If that rotor is discolored, it has reached a high enough temperature to boil the fluid. Did the car sit for a prolonged period? If so, you should replace all the hoses and put caliper kits on all four corners. If that rotor is discolored you should replace it too.
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Mr. Shannon DeWolfe -- (I've taken to using Mr. because my name tends to mislead folks on the WWW. I am a 51 year old fat man ;-) -- KD5QBL

If it is just at one wheel, I wouldn't suspect the master cylinder. I'd have close look at the caliper at that wheel-- can you push the pistons back easily on both sides, or does one side appear to be hung up? How about the pad wear-- does one side show wear and the other much less?

Another longer shot-- I've seen bad brake hoses that had pockets inside that ended up working like a one way valve, keeping the pressure on the pistons in that caliper and causing it to drag.

Good luck!

I guess my next question would be would 1 caliper piston trouble cause a total loss of brake pedal? I used new fluid from a sealed container, bench bled the master cylinder then each caliper. The really strange thing is that once this happens and you pump the brakes back up they are fine, no loss of pedal, no dragging brakes, even braking, good pedal pressure, as though nothing was ever wrong. This is too weird.
Thanks.
Chuck Jaxel.
Pulling wheels and calipers in Jersey.

another possibility is water in the brake fluid - it can heat up under use and vaporize and drive the caliper piston(s) out so you end up with smoking brake pads.
if you thoroughly bleed the brakes you'll have all new fluid in the lines, which is a good thing anyway, and you'll get rid of water if that's the problem.