Anthrax Mike

Alright my car experienced some brake fade, to the extent that I drove through a red light because the pedal was to the floor. This happened only after about a half hour of continous driving. I had no idea how old my brake fluid is so maybe it just overheated and boiled.

So I completely purge out the old brackish fluid for some clear stuff. I then drove it around for about an hour when the same deal happened. It fell to the floor, pump it a few times and it was ok, but it would happen again and again if it was continued to be driven.

I check the front wheels when I get back, the left front is hot but the right front is scorching hot. When I jacked up the front end the left side spins freely but the right is of course frozen. I brake down the right side assuming my caliper is hanging up, but its not the slides are fine and the piston compresses easily. And once compressed, the hub turns. I put it back in place step on the brake, and the hub again doesn't turn.

So basically its staying hydraulically applied. I followed the lines to see if it was pinched anywhere and its not. Has anybody had a proportioning valve do this to them? Because the right side is the only line which runs through the valve, other than the rear brakes. The left side is a straight shot from the master, so it seems a possiblity, both front brakes share the same cup in the master correct?

I wanted some feed back before I throw money at the problem, it doesn't seem like the caliper because it moves freely. All that returns that caliper piston is the boot correct?

Thanks to all who take the time to read this.

There are some simular topics when I searched but nothing that matched.

purple82

It sounds like it's just your master cylinder seals, but I'm not sure why you'd have different temperatures between your front wheels. I'd try the master cylinder first though, the fact that you can pump it and get pressure is a sure sign.

Anthrax Mike

I guess my thought was, why is it only once it gets hot. It should happen far more frequently I'd think if it was a master problem. I think the that by pumping it I'm merely compressing the air from the boiled fluid.

Its kinda bizarre that the master would keep the left side fully applied, but not the left. Unless someone can explain that one to me.

OnlyOnThurs

Don't ask....REPLACE IT before you don't have any pedal at all!!!!!

trochoid

iTrader: (6)

Left front wheel has a seperate line off the master, the right front goes to the proportioning valve for the rear brakes.

neektar

iTrader: (2)

if the front calipers are both different temperatures, not slightly but completely I would first replace the master cylider to make sure the brakes work then go to an open area with about 30ft of clear space, puch it then stop. if the car sways to the l;eft or right the opposite caliper is frozen and needs to be replaced/rebuilt.

but from what ur saying it seems like the right one is almost 100% frozen.

Kentetsu

Master cylinder...

1revnrex

Ive got the same prob right now man, pedal looses pressure - have to pump the brakes. Its the master cylinder. Just replace it.

Anthrax Mike

All righty. I know I'm flogging a dead horse, but I wanted to give a resolution to this thread. I resolved my problem and wanted to post it so in the future if anyone else has a simular situation.

The problem was a bad caliper. No the caliper was not frozen, as the piston moved easily as were the slides. It for whatever reason lost its ability to return after being applied. I found this by cracking the line in different places to see if by doing so allowed the pressure to be released at the caliper.

I started at the master, open a line slightly to allow fluid to bleed out, attempted to move the wheel, closed it and then moved on to the next fitting in the line. I made it all the way down to the caliper bleeder and the wheel would still not spin. Abracadabra. Brake caliper replaced. Its fixed.

Been driving it for two days with no incident. The caliper releases the brakes and the excessive heat I felt from the right front is gone.

So if you have a brake that is staying applied all the time. But the piston is not frozen and moves easily, and relieving pressure at the caliper, replace the caliper. For the fluid will boil, you will not stop, and you will die!!!!!!!!