Resetting the prop valve on a new sysytem

[my new 72]

Just what the heading says. I am replacing the whole brake system except for the prop valve because it is only a year old and still works, but I noticed when I took it off, the valve was not centered, meaning that there was no fluid being pumped to the rear lines. When I put everything back together, how do I reset the prop valve and bleed the brakes properly? Thanks for all the help in advance.

[aesj2]

The 72 service manual says to push in the pin in the end of the valve. This is the open position and the pin can be held in with tool J-23709 or a small C-clamp.
Hope this helps.

[aesj2]

Forgot to add the "reset" procedure. To reset apply heavy pedal force. The force of the hydraulic pressure will re-center the switch.

[my new 72]

This is not working for me. I tried and tried to do it this way, but no luck. This is killing me. I decided to go ahead and bleed the fronts so I can at least drive it to a shop if I don't get any answers here. I am stumped. HELP! I would rather not pay anyone to bleed the brakes for me.

[Irnoti]

Hey,

I have centered many of these valves. HERE'S HOW:With valve off center as you say, and it is blocking the rear outlet, then open the front bleeders (on the front brakes) make sure the master cylinder is filled, sit in the sit as though you are driving and stomp as hard and fast on the brake pedal as you can (Prop. Valve must be installed). it will make a mess but it will center the valve again. NOTE: You could put rubber lines on the bleeders and set them in a small can to try and catch the fluid that is forced out. ALSO: Make sure you are in fact getting fluid out of the front bleeders before attempting, if not, clean them out first. You should have a light on the dash labeled 'brake' and if it's working correctlyand hooked up, it should be lite when you key on, indicating the prop. valve is off center. And after you center the valve by using the method above, the light will be off, hence, key on during the procedure and you will have visually confirmation that the valve has re-centered. If that doesn't work I have a few other tricks you can use. Email me. Sksjp@aol.com. Good Luck

[my new 72]

Thanks for the suggestions guys. It'll have to wait untill Saturday, but I'll get back on it then.

[my new 72]

Got em bled, but the valve is still not completely centered. The fluid just barely comes out of the rear bleeders though. What can I do to center the valve the rest of the way?

[Irnoti]

Did you make sure the bleeders were clear? This is important. If you still have wiring lead connection on the valve you can also check it for continuity through the valve, if it's still not centered there will be continuity through the switch to the body of the valve, if I remember correctly.

[my new 72]

The bleeders are very clear, they shoot out fluid about five feet when I bleed them. Plus all the lines are new and so are the calipers and wheel cylinders.

[my new 72]

I should add that I have never had any problems with the brakes on any other vehicle before, it's just this damn prop valve that is killing me.

[Irnoti]

Sorry,

Are the rear bleeders clear, obviously the fronts are clear, you didn't mention that they were 'barely drippling fluid', as you did on the rears. So, now what condition is the fluid motion for the rear, does it just barely come out or does it shoot out five feet?

[69sixpackbee]

Put an adjustable one on it and be done with it!

[my new 72]

I got them working. My brother and I bled them again today on our lunch break. We used a c-clamp to hold the pin in and bled the rears. When we held the pin in to bleed the rears it shout out all the way to the other side of the pumpkin, so the rears are good, and the fronts were already bled, so we left them alone. When we took off the c-clamp and buttoned it all back up everything was good. It even locked all four of em up, and with 18x8.5 wheels and 255/55/18 rubber that is saying alot. Thanks for the help guys, I am indebted.

[69sixpackbee]

Congrats, man!