COmbination Valve tool

[edpdx50]

My dash BRAKE lamp has been stuck on for a year or so. I finally am getting around to fixing the problem. (It's not a daily driver ). So because the job is very tedious with the valve and all the delicate brass lines stuck behind the hood hinge, I don't want to have to remove the rebuilt combination valve anymore than necessary. I made a piston centering tool from the old Brake light switch- it keeps the piston in center of valve while bleeding- I'm told.

I started to bleed the rear passenger side with a vacuum bleeder. I got very little fluid. To see if it was a bad wheel cylinder, I tried the driver rear... same deal- no fluid. I am hearing a leak that seems to come from the booster behind the master cylinder. The brake pedal is still strong. Is the MC the culprit, or is the booster failed and it has to be replaced.The booster looks stock, so a new one is probably in order, but is a failed booster the reason the rears are not yielding fluid?

I'm only asking because I have never used the Combination Bleeder tool before. Any trick to use it properly? I just installed it and started bleeding as usual. Could I be doing something wrong with the tool- somehow blo9cking the rear lines?

 

[tony-muscle]

I may be wrong but in your situation if you open a front bleeder and stump on the brakes may recenter the valve. You dont have much to lose if it doesnt work.

I never used the tool you are talking about.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[Bill73Ragtop]

I've never had great luck with using hand vacuum pump to bleed brakes. It did okay with getting the flow started, but never really pulled a lot of the air out of the lines.

I used it to get the process started on all four wheels and then used a helper to hit the brake pedal for strong flow that carried any bubbles out.

The centering tool (bolt) I've used has a tapered point which holds the piston centered in the bore. I'm not sure how an old switch works since the plunger is spring loaded and is designed to complete the circuit, not hold the piston centered.

 

[Don C]

Unless you centralized the pressure differential valve in the proportioning valve before you installed the tool, the tool will hold the valve off-center, and keep it from returning to center. It will not center the valve.

You can get these speed bleeders to do the job by yourself, by pumping the brakes.

http://speedbleeder.com/