Brake Warning Light (not Brake Lights or Lining warning)
Posted: Sat Feb 18, 2006 6:21 am
The brake warning light popped on today on my '87 635 and stays on.
Now, the brake fluid level is fine and when I unplug the leads to the brake fluid level switch the light stays on. So I unplug the two switches on the regulator and sure enough the light goes out when I unplug the switch on the side of the reg. (all with eng. running).
So, here is the question:
What does the switch on the side of the regulator measure/indicate?....
(The parts cat. lists this as a 20 bar or 292 psi switch)
Anyone have a flow diagram or system description of the regulator?
I've pumped the brake pedal and discharged the accumulator and the fluid level rises to the top and disappears when the engine is started. So the accumulator seems good.
The website realoem.com calls the side switch an "oil pressure switch" and the top switch the "brake pressure differential switch".
While the component locating section of the 1985 BMW 635Csi Electronic Troubleshooting Manual Online, calls the side switch a "brake accumulator pressure switch" and the top switch the "hydraulic pressure switch"
and the Bentley manual just calls them both "hydraulic pressure switchs"
Now, the brake fluid level is fine and when I unplug the leads to the brake fluid level switch the light stays on. So I unplug the two switches on the regulator and sure enough the light goes out when I unplug the switch on the side of the reg. (all with eng. running).
So, here is the question:
What does the switch on the side of the regulator measure/indicate?....
(The parts cat. lists this as a 20 bar or 292 psi switch)
Anyone have a flow diagram or system description of the regulator?
I've pumped the brake pedal and discharged the accumulator and the fluid level rises to the top and disappears when the engine is started. So the accumulator seems good.
The website realoem.com calls the side switch an "oil pressure switch" and the top switch the "brake pressure differential switch".
While the component locating section of the 1985 BMW 635Csi Electronic Troubleshooting Manual Online, calls the side switch a "brake accumulator pressure switch" and the top switch the "hydraulic pressure switch"
and the Bentley manual just calls them both "hydraulic pressure switchs"