chickenminer
Well-Known Member
I have a '93 A35 with a brake issue that is driving me nuts! Have had brake issues every since I got this truck, low brake pressure light would go on/off. Finally a couple weeks ago I lost brakes altogether. No pressure at all. Pulled the brake pump and it looked wore out inside. So I got a new OEM brake pump that cost me 2K. Put the new pump on and all was good. Pressure light went out and had good brakes. Used the truck for two days and started having the brake light come on again !
Put a pressure gauge on the test port on the unloading valve and I can only get a max of 1000 psi. Ran through the whole brake bleeding procedure again and still no higher than 1000 psi.
So then I tried to adjust the pressure according to the book and no matter how much I turn the set screw on the adjustment the pressure never raises or lowers!
Could it be a bad unloading valve? How could I test this? I can't believe it's the pump as it is brand new. I also changed the filter when I installed the new pump.
What am I missing ?
Put a pressure gauge on the test port on the unloading valve and I can only get a max of 1000 psi. Ran through the whole brake bleeding procedure again and still no higher than 1000 psi.
So then I tried to adjust the pressure according to the book and no matter how much I turn the set screw on the adjustment the pressure never raises or lowers!
Could it be a bad unloading valve? How could I test this? I can't believe it's the pump as it is brand new. I also changed the filter when I installed the new pump.
What am I missing ?