Originally Posted by trifivefan
- My car has a power front disc/rear drum setup using a 7in dual diaphram and remote filled master cylinder that sits beneath the floor.
- The combination valve is for disc/drum applications and has a metering valve and proportioning valve in one unit. I have a 10 lb residual to the rear and 2 lb to the front. The remote filled master is 15/16 in bore size. Any help would be greatly appreciated.
Originally Posted by trifivefan 09-30-2006 11:23 PM
I have a master below the floorboard on my 40 ford 327 with disc front and drum rears.
- I had adequate braking before my car sat for about 5 weeks while getting upholstered. When I got the car back I noticed I had hardly any brakes. I was told that since I did not install a 2lb residual to the front brakes the fluid drained back to the master.
- I installed the 2 lb around 6-8 inches from the master and bled the brakes---all four of them, several times. I still have no brake pedal and now when I step on the brake hard to stop, the pedal sticks to the floor and I have to literally lift it with my foot.
- I ensured the master never lacked brake fluid during the bleeding, I don't have any leaks in any of the brake lines. The only thing I did different was add the 2lb residual and close off one of the ports from the combination valve.
- Before, I used both ports on the valve to run a line to the left and right front wheel. This time, I come off the combo valve with one line into a brake tee and tee off to each front wheel. Therefore, I plugged off one of the front wheel ports on the combo valve. The remote filled master has a 15/16 in. bore.
(sounds like a two-peckered toad in mating system
) makes a good suggestion-failed M/C. But what confuses me is the pedal sticking.
I am assuming the booster/master cylinder/combination valve was a complete kit (with adequate instructions to install it properly, or is this a combination of take-off parts?
You said origionally you had adequate
brakes? Either you have good brakes or don't. You said origionally, the metering valve portion of the combination valve had two outlets and you only used one with the installation of the 2 lb residual valve. Did everything start at this point?
You do have the front calipers installed on the correct side and the bleeders pointed straight up to eliminate the air in the front circuit entirely?
I would start by bench bleeding the M/C again (this can be done on the car) and if necessary pivot the caliper so that the, bleeder valve is pointing directly upwards to allow all air to be expelled from the front circuit. Ascertain correct pushrod adjustment and brake pedal linkage operation (and ratio) (no binding) to see if that is contributing to the pedal sticking to the floor. You may also want to remove the booter assist (vacuum signal) to see if the hydraulics are working properly (test only-no drive)
Who supplied the proprtioning valve and is it's bias set to your chassis weight?
Both illustrations show under-floor mounting;