|09-22-2002 08:09 PM|
|NAIRB||I finally figured this deal out. I ended up replacing the rear calipers, but I couldn't get them to "pump up" after I put them in. The brake light was on, and would flicker if I stabbed the brake pedal hard, so I replaced the proportioning valve with a high quality used unit, and that cured my fluid flow problem. I bled this baby until I was blue in the face, but the pedal would always be soft, and the rear calipers would retract after I let off the pedal. Once I had the calipers relatively full of brake fluid and free from air, I had to remove the emergency brake levers and tighten the nut up until the brake pads were loaded against the rotors, then I reinstalled the levers, so that the emergency brake levers kept the brakes loaded and VOILA!!!!!! I had a tight pedal, sometimes the obvious eludes us, doesn't it? I messed around with this car on and off for four days, and my customer was mad as a wet hen, but alls well that ends well.|
|09-18-2002 01:23 AM|
Did you replace the rear flexible brake hose?
You might also want to remove the inlet line at the valve and see if flow is available there. If it is, it is a bad valve.
From Master Power Brakes Website;
A tripped combination valve.
If you lose half your braking system and the combination shuttle valve cuts off half the system this can give you a hard pedal. This type of combination valve can be tripped during the bleeding process. To center the valve open a bleeder screw on the half of the system that still has pressure. Depress the brake pedal and tighten the bleeder screw. This should center the valve.
|09-18-2002 12:06 AM|
|4 Jaw Chuck||Are you holding down the brake pedal when you are bleeding?|
|09-17-2002 09:59 PM|
Brakes on Toro
This is an ongoing problem for me. I am working on an 83 Olds Toronado. The rear brakes were not working well, and the emergency brake didn't work at all. This car has rear disc brakes with the emergency brake lever built into the caliper. This car has had the master cylinder replaced, and the rear calipers, but now I can't get any decent fluid pressure to the rear brakes. I've deducted that the proportioning valve is stuck. I've used suction to pull fluid to the calipers, and manually bled the brakes until I'm blue in the face. The master cylinder was bench bled properly and even returned and replaced with another unit, but the same problem persists, I get a dribble of fluid to the back, but not any good hydraulic pressure. Any ideas? Is this the proportioning valve giving me fits, I almost think it has to be, but I suppose there could be another restriction somewhere, but I don't think so.