Does anyone have a spare master cylinder cap for an 87 that they do not need? One of the things that I do to all of my race cars is get a spare cap for the master cylinder, drill a hole in it, and adapt a male quick disconnect air compressor fitting in it, then put a big vaccumn cap over it. That way, when you want to bleed brakes or change fluid, you just fill the resevoir, turn the air compressor pressure down to 10psi (dont forget to do this and leave it at the same 120psi you had to take the wheels off or it will immediately explode - my friend did this not once but twice), put the female quick disconnect fitting from the air hose on the master cylidner, pressurize the master cylinder with 10psi, crack the bleed screw, and watch the fluid flow. You will never need two people to bleed brakes again.
MASTER CYLINDER CAP NEEDED - BRAKE BLEED TIP TOO
A much better solution is to purchase a Motive (or equal) pressure bleeder. It does everything your modified cap does (without needing compressed air) and allows for flushing of the brake system w/o a risk of running the reservoir dry.
Thanks for the idea, but I have a Motive power bleeder. I do not like it. First things first, it is horribly messy to use. Second, I am starting to use expensive brake fluid, and the Motive unit leaves quite a bit in the bottom. I never run the resevoir dry, I keep a pretty close watch on it.
A mess when using a Motive bleeder sounds to me like you aren’t ending the flush/bleed job correctly. Once the flush or bleed is complete, turn the bleeder upside down and bleed enough fluid from the left front wheel to clear fluid from the tube and lower the level in the reservoir to the MAX mark. Then release the pressure by cracking the bleeder cap before removing the fitting from the reservoir.
My Motive only leaves about a half ounce of fluid in the reservoir. Perhaps the pickup tube in yours is a bit short.
Now here is a question. I just got done reading up a bunch on bleeding, whether or not you need to activate the ABS pump, etc. If you put the car on jackstands, start it and leave it running, and put a pressure bleeder on the master cylinder, does it bleed the fluid out of the ABS pump and system or not?
Also, if you just bleed the brakes with the power bleeder but without the car running, does it bleed the fluid out of the ABS pump and system or not?
Whether the engine is running or not has no affect on bleeding the brakes. Unless activated by the ABS module the ABS pump is in the same state with the engine on or off.
Brake fluid flows through the ABS pump, so that part does get flushed/bled. But there is internal volume in the ABS pump that is only exposed to a flush/bleed when the valves in the ABS are open during ABS activation. On later cars the ABS pump can be placed in bleed mode via a DIS or GT-1 diag system. But other than taking the car out to a wet parking lot and engaging the ABS I know of no way to do that on an E30.