Brake work, bleeding question

[jooset]

Quick refresher. I'm installing my adjustable proportioning valve in the rear brake line. As a matter of course, drained all the fluid out of the rear brake reservoir and uncovered the port (front reservoir). When I put it all back together, I need to get the air out of the PM first which I can do by putting fluid in the reservoir closing it up, having a friend depress and hold the brake, cracking the rear brake fitting at the PM letting the air (and some fluid) escape. Do that a couple of times for good measure. Then bleed the four wheels like normal.

Sound right?

Thanks in advance,
Matt

 

[gofstbuick]

Actually if there is no fluid in the PM reservoir, leave it that way and bleed the brake system first (with the ignition off). You can leave the reservoir uncovered and bleed the brake system mormally. The reason fluid goes everywhere is because the bladder of the PM system is pushing through the return port of the PM reservoir. After you finish bleeding the brakes, add fluid to the PM reservoir. Turn the key on and the PM motor should run for no more than 20 seconds. If it does, turn the ignition off and bleed the PM. This is accomplished by loosening the feed hose (attached to the metal pipe) at the master cylinder, until fluid flows. DO NOT COMPLETELY REMOVE HOSE, PM SYSTEM EXCEEDS 700PSI!!!!!!!. I CANNOT STRESS THIS ENOUGH!!!!!! Then add some fluid and key on engine off. PM motor should not run for more than 20 seconds. Additionally, the front port of the PM reservoir is the suction port. That port should always be covered with brake fluid. If the port becomes uncovered, add just enough fluid to cover the port.

 

[jooset]

Thanks - clarification

Thanks for the reply! Now that I'm back from a week on travel...I get to try this again. I did not drain the fluid out of the passenger side of the reservoir (this time). The only port totally uncovered was the front port on the driver side (rear brakes). I don't know how you'd bleed the brakes without brake fluid in the reservoir to feed the lines (which now contain a bunch of air). So I was talking specifically about the front port on the drivers side being uncovered prior to my refilling and bleeding. Don't know if this makes a difference on your comment. Thanks for your time.

Matt

 

[gofstbuick]

If the front reservoir is empty, then you'll probably need to bench bleed the m/c. NAPA sells a bench bleed kit. You'll need to empty the power assist side of the m/c reservoir (largest reservoir), remove the front brake line and install the bench bleed hose and fitting on to the m/c. Fill the front reservoir with fluid and pump pedal until there are no bubbles. Remove fitting and hose, and gravity bleed the rear brakes or use an approved brake bleeding method for the rear brakes. Then fill the power assist side and use the procedure I outlined in the previous post.