Bleeding prop valve, how the hell does it happen???

[sixty4bigwindow]

Ok, system is all hooked up and sealed. But now trying to bleed it has been a nightmare. I have the cpp prop valve connected to a dual reservoir MC from a 73 c10. Is there a special way to bleed since it has a prop valve?? I tried to bleed with a vacuum bleeder and with a buddy pumping the pedal.. nothing. Ive seen a prop valve bleeder tool online, is tht what i need to bleed the system properly??
Thank you in advance!

[The Rocknrod]

Originally Posted by sixty4bigwindow

... Ive seen a prop valve bleeder tool online, is tht what i need to bleed the system properly??
Thank you in advance!

Yes, that's why they make it.

[64shortbox]

I'm not sure about a CCP proportioning valve but on a GM one - yes you need the special tool to keep the combination valve centered. On a factory GM proportioning valve - remove the Brake switch from the middle of the valve - if you look inside you should see a small grove in the shuttle valve - reach in with a small screwdriver and center the grove in the switch opening. Install the holding tool - bleed the brakes like you normally would - after you finish bleeding remove the tool and reinstall the Brake switch.

I went with all factory 73 C10 stuff because I'm a Cheap SOB, even reusing all the hard brake lines and proportioning valve - I did have to make my own mounting bracket for the proportioning valve though. I then STOLE the idea to use a modified 73 brake pedal and suspended throttle pedal. Are these trucks ever done?

I hope the attached pictures help.

[sixty4bigwindow]

Yes thank you both for the input. Ordered the bleeder, guess I'll have to wait for the road test until the part gets here. Thank you guys for the help, this community rocks because of your help!!

[jocko]

The master cylinder itself must still be bled - the POL distro block lock doesn't accomplish this. The way to bleed a master cylinder is to have it off the truck, run lines from the outlets that loop back into the reservoir, and gently pump the rear piston in and out about an inch until all the bubbles are gone in the reservoir - then reinstall the mc.

Having said all that, the mc "should" have come with bleeding instructions for the mc itself (some factory replacements recommend bleeding with the ports plugged, not looped back into the reservoirs - I've done this way too, and it worked and was less messy) - but who knows what you get with CPP. Even if the MC is good - it takes a good long time to get the rest of the system bled - bottom line: don't give up with the buddy method, takes some time.

You might also google gravity bleed on this site, some folks swear by it (I'm not one of them, but I haven't tried it yet). The only thing pressure or vacuum bleeders ever got me was covered in brake fluid (especially the pressure type - yech, ha). I'm quite certain it was user error, but once you're covered in brake fluid and it's all over the engine compartment you just painted because the sealing mc cap that came with the kit didn't hold, well, at that point it just doesn't matter who screwed the pooch, you're the one that's all wet.

[The Rocknrod]

Originally Posted by jocko

... The only thing pressure or vacuum bleeders ever got me was covered in brake fluid (especially the pressure type - yech, ha). I'm quite certain it was user error, but once you're covered in brake fluid and it's all over the engine compartment you just painted because the sealing mc cap that came with the kit didn't hold, well, at that point it just doesn't matter who screwed the pooch, you're the one that's all wet.

Now I don't feel so pregnant.

[rustbucket66]

Sounds to me like you need to bench bleed the master cylinder if you haven't already. Follow the instructions that "Jocko" posted, then bleed each wheel like you have been doing. You can bleed for days and not get it if the m/c isn't bench bled to get all the bubbles out.

[sixty4bigwindow]

Sorry took so long to reply fellas. Flying to AZ to say goodbye to 96 year old Grandma who is fading... but next week the POL will be here and I will try and bleed with that. Everything else I've read sounds like that is the way to go. My buddy and I tried the regular bleeding and it was a no go at all. I did do the "bench bleed" on the MC. It was on the truck, and just took my bleeder pump and put the hose to each of the fittings and pumped it out. Thats how i got to the point that i knew it was the combo or prop valve not bleeding properly. Ill be sure and rebleed the MC when i go to finish it. Thanks again for all the input, and next time i will refrain from fornicating with the k9 😂😂😂

[andyh1956]

Does anybody (GM maybe?) sell a kit to re-seal these valves? As an important part as it is I'm sure this valve gets overlooked for PM.