Enabling Rear Breaks

[ruzztec]

I had a line tear at the rear diff. i Bent a new one but notice i cant bleed the system.....theirs no fluid going to the rear breaks. Just the front. I heard and presume that the shut off system somewhere at the master cylinder tripped the system and stopped sending fluid back there...or am i nuts and have a pinched line?

 

[firepop5]

I never heard of a shutoff at the MC. Maybe the calipers or wheel cylinders are frozen. If they are frozen, it could cause the line burst. Loosen the fitting at the caliper/wheel cylinder and have a helper step on the brake pedal. If fluid comes out, they are probably frozen. If no fluid comes out, your blockage is further up the line.

 

[Carguy3J]

I think you are thinking of the proportioning valve, metering valve and/or combination valve. There is a little piston in there that can get stuck off-center when one of the brake hydraulic circuits (front or rear) loses pressure. This does act as a sort-of safety feature to ensure that you still get as much braking as possible from the remaining circuit. Sometimes you can get them recentered. Sometimes your need to replace it. I think there is some more detailed info somewhere on the forum. Try searching. If not, ask a mechanic about it.
I've heard of this, and I get how it happens, but I've never experienced, and I don't think I can really offer any more help in that regard, but I think the prop valve is going to be where you should look, assuming you don't have any more leaks, and you're definitley not getting any fluid to the rear brakes.

 

[Carguy3J]

I never heard of a shutoff at the MC. Maybe the calipers or wheel cylinders are frozen. If they are frozen, it could cause the line burst. Loosen the fitting at the caliper/wheel cylinder and have a helper step on the brake pedal. If fluid comes out, they are probably frozen. If no fluid comes out, your blockage is further up the line.

He said that he can't bleed them. Even if the calipers were frozen solid to the rotors, you'd still get plenty of fluid coming out of an open bleeder screw. More, in fact, since a frozen caliper isn't going to allow the piston to move. Therefor, the fluid/pressure would have nowhere to go but out the bleeder.

Also, FYI, a 2nd gen Explorer isn't going to have wheel cylinders. Those are for actuating drum brakes only. All 2nd gen Ex's have 4wheel disc.

EDIT: OOPS! I just noticed that the original posters signature says he has a '92 Explorer. In that case he would have drum rear, with the wheel cylinders. To the O.P., if this is the vehicle you are working on, you posted it in the wrong section of the forum. The 1st gen's (1991-1994) have their very own sections. You might get better help. with more specific info from people in there, familiar with your body style/year

 

[ruzztec]

this explorer in a 99 XLT. I have two. The ripped line would leak and leak then stopped one day...i was going thought about 1 large container of b-fluid a day. I found the busted line and replaced but never saw fluid come out.

 

[Cobraguy]

You were driving a car that was using a quart of brake fluid a day????

 

[ruzztec]

had no choice...had to get to work...was mainly using (P)break to stop and gears to slow down. Finally got a chance to sort out the prob...caliper line on front driverside was ripped and the tear in the steel lines in the rear. replaced front caliper line and rear line but was never able to bleed the rear

 

[BrianDye]

You were driving a car that was using a quart of brake fluid a day????

 

[bluestream1]

had no choice...had to get to work...was mainly using (P)break to stop and gears to slow down. Finally got a chance to sort out the prob...caliper line on front driverside was ripped and the tear in the steel lines in the rear. replaced front caliper line and rear line but was never able to bleed the rear

you're a braver man than I...

 

[Cobraguy]

you're a braver man than I...

That isn't even close to the description I have of him. My God.

 

[ruzztec]

lol i drove it for about a week like that...had 2 close calls..(P) break needs to be tightend now!

 

[ruzztec]

Ok update...both rear calipers get fluid but neither are doing any breaking...is it possible that both failed at the same time?