Part No for Brake Combination Valve - The 1947 - Present Chevrolet & GMC Truck Message Board Network

pickupman · 04-07-2021, 09:09 AM

Inline tube

**HO455** · 04-07-2021, 11:20 AM

Before changing the valve check the pressure between the valve and the master cylinder. It is far more likely that one of the rubber items in the brake system has failed, compared to a failure of a part with no rubber components. The rubber items will degrade over time or can physically react to different kinds of brake fluid.
The cups in the master cylinder and the hoses would be my number one items to check.
And if pressure tests of the master cylinder check out only then I would remove the valve to clean and verify the spool inside was stuck before buying another one.

**Grumpy old man** · 04-07-2021, 11:36 AM

I just ordered these parts for my neighbors 71 , He tried bleeding his brakes without the tool and lost his front brakes .

https://www.youtube.com/watch?v=xrjENVu1Bxk start video at 2:40

https://www.summitracing.com/parts/clp-pv-2

https://www.summitracing.com/parts/clp-pv-tool

Bbarbeau · 04-07-2021, 11:39 AM

Thanks for the replies everyone.

Do you think the reason they aren't at NAPA because they don't fail often?

I did try to center it manually but it appeared to already be centered. The dash light isn't on but that's because I discovered that the wire is totally disconnected (sigh). When I checked the valve with a meter it doesn't seem like the valve is triggered because there isn't continuity.

Interesting thought about the other components, thanks for the suggestion. Master cylinders are fairly cheap - I'll check flow and if it's suspect, replace it then. Will have a look at the hoses this afternoon. Probably a good idea to just replace those since it's new to me.

04-07-2021, 09:09 AM	#1
pickupman Registered User Join Date: Dec 2000 Location: Greeneville, TN Posts: 3,095	Re: Part No for Brake Combination Valve Inline tube __________________ atheystruck@comcast.net 67 1/2 ton 4wd custom cab 72 1/2 ton 4wd super cheyenne 71 1/2 BB super cheyenne shortbed

04-07-2021, 11:20 AM	#2
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 11,216	Re: Part No for Brake Combination Valve Before changing the valve check the pressure between the valve and the master cylinder. It is far more likely that one of the rubber items in the brake system has failed, compared to a failure of a part with no rubber components. The rubber items will degrade over time or can physically react to different kinds of brake fluid. The cups in the master cylinder and the hoses would be my number one items to check. And if pressure tests of the master cylinder check out only then I would remove the valve to clean and verify the spool inside was stuck before buying another one. __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377

04-07-2021, 11:36 AM	#3
Grumpy old man Senior Member Join Date: Dec 2013 Location: Gods country East,Tn Posts: 8,545	Re: Part No for Brake Combination Valve I just ordered these parts for my neighbors 71 , He tried bleeding his brakes without the tool and lost his front brakes . https://www.youtube.com/watch?v=xrjENVu1Bxk start video at 2:40 https://www.summitracing.com/parts/clp-pv-2 https://www.summitracing.com/parts/clp-pv-tool Attached Images __________________ 1967 Factory short bed - Old school '71 - 350 / 4bolt / 487 heads / Edelbrock C3BX Muncie M-22 4 speed / Hurst Comp plus Factory 12 bolt posi 3.73 / 255-70-15 Smoothed firewall / Factory cowl induction Power disc brakes / power steering / 3.5-5" drop Last edited by Grumpy old man; 04-07-2021 at 11:54 AM.

04-07-2021, 11:39 AM	#4
Bbarbeau Registered User Join Date: Oct 2020 Location: Kingston, ON Posts: 67	Re: Part No for Brake Combination Valve Thanks for the replies everyone. Do you think the reason they aren't at NAPA because they don't fail often? I did try to center it manually but it appeared to already be centered. The dash light isn't on but that's because I discovered that the wire is totally disconnected (sigh). When I checked the valve with a meter it doesn't seem like the valve is triggered because there isn't continuity. Interesting thought about the other components, thanks for the suggestion. Master cylinders are fairly cheap - I'll check flow and if it's suspect, replace it then. Will have a look at the hoses this afternoon. Probably a good idea to just replace those since it's new to me.



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