Proportioning Valve and Bleeding

[Raoul Ross]

Another issue on this 85 C10 Suburban cropped up while replacing the fuel pump (the original problem). While replacing the fuel pump the proportioning valve started weeping, all by itself. You know how it goes, bring a neglected vehicle in to work on one problem and another pops-up.

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Found a replacement valve (not easy anymore) but I have one question about bleeding the system after replacement... is there a tool to keep the internal valve from moving while bleeding or should I just use a pressure bleeder on the M/C and open the wheel bleeders? It's been a while since I've done one.

 

[jh86]

I used the tool that threads into switch location

 

[Raoul Ross]

I've kinda looked around for that tool but not finding it... what's it called? Gotta P/N or manufacturer?

 

[Ken B]

Proportioning valve bleeder tool. Amazon 7 bucks

 

[jh86]

This is the one I bought

https://a.co/d/8EupJ1X

 

[ali_c20]

You could gravity bleed the brakes. No pumping and tool required.

 

[Raoul Ross]

Ordered the 'Tool' at Amazon, Thanx guys!

I will try pressure bleeding first and then do the pedal pumping thing if I'm not satisfied.

 

[Toad455]

I just bought the same tool and a new PV_4 valve. I've never used this tool before so I'm interested how it works out for you, I still have to install new lines, master, etc on a new build so it'll be a while before I get to it.

 

[Raoul Ross]

Replaced that proportioning valve and bought a fancy vacuum bleeder, which worked quite well except for one thing. As it pulls the fluid from the wheel cyl/caliper, it also pulls air from around the bleeder threads so you never know if you've got all the air out. I just went by the color of the fluid as the original fluid looked exactly that, the original 1985 brake fluid!

I did buy a locking tool for the P-Valve. It was a pretty red anodized unit... I'm a sucker for anything anodized red, lol.

I still wasn't sure though if all the air was out so I resorted to doing the pedal-pumping method. Every bleeder had a small initial burp of air. It must get sucked in from the vacuum as I closed it off. Otherwise the vacuum bleeder werkt quite well! Not much room to swing a wrench though, took me an hour to get the old one out!

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[Goldie Driver]

Save your old valve. My PV2 lasted around 2 years and started leaking. I noticed no difference between the new and the old and the old one is back on the truck. With no leaks !