Problem with master cylinder and proportioning valve - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Ackattack · 06-17-2009, 12:24 AM

I tried to hook up my proportioning valve tonight to my master cylinder and it doesn't fit correctly.

The proportioning valve is a disk-disk unit from CPP

I believe the master cylinder is from a 72 3/4 ton (front disk, power brakes).

Do I need to get a 1/2 ton master cylinder? The part number is in the one picture.

JimKshortstep4x4 · 06-17-2009, 07:35 AM

Your MC is from a 3/4 ton truck so the rear reservoir would be plumbed to the front brakes and the front reservoir would be plumbed to the rear brakes.

A 1/2 ton MC is plumbed just opposite so it should fix your problem.

Jim

mbgmike · 06-17-2009, 06:53 PM

Why is your valve and braket upside down?

Ackattack · 06-17-2009, 08:51 PM

Quote:

Originally Posted by mbgmike

Why is your valve and braket upside down?

that's the only way it would hook up......see answer above

I got a new MC, I assume it will hook up correctly

chas350 · 06-17-2009, 09:35 PM

Quote:

Originally Posted by mbgmike

Why is your valve and braket upside down?

What he said x2

Ackattack · 06-18-2009, 01:39 PM

I got a new 1/2 ton MC and all is good, thanks guys!

06-17-2009, 12:24 AM	#1
Ackattack Senior Member Join Date: Aug 2002 Location: Valley Center KS Posts: 3,525	Problem with master cylinder and proportioning valve I tried to hook up my proportioning valve tonight to my master cylinder and it doesn't fit correctly. The proportioning valve is a disk-disk unit from CPP I believe the master cylinder is from a 72 3/4 ton (front disk, power brakes). Do I need to get a 1/2 ton master cylinder? The part number is in the one picture. __________________ Project Bruiser: 68 Pro-Touring C-10 5.3L / 4L60E Project Ironhide: 97 GMC Crew Cab 4x4 Cummins SOLD: '69 GMC 1/2T SWB TBI'd: Project No Buck Assembly Manual Index Sign up Thread!!! Factory Service Manual Index

06-17-2009, 07:35 AM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: Problem with master cylinder and proportioning valve Your MC is from a 3/4 ton truck so the rear reservoir would be plumbed to the front brakes and the front reservoir would be plumbed to the rear brakes. A 1/2 ton MC is plumbed just opposite so it should fix your problem. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

06-17-2009, 06:53 PM	#3
mbgmike Registered User Join Date: Aug 2005 Location: Pasadena,Tx /Pto Pta DR Posts: 5,415	Re: Problem with master cylinder and proportioning valve Why is your valve and braket upside down?

06-18-2009, 01:39 PM	#6
Ackattack Senior Member Join Date: Aug 2002 Location: Valley Center KS Posts: 3,525	Re: Problem with master cylinder and proportioning valve I got a new 1/2 ton MC and all is good, thanks guys! __________________ Project Bruiser: 68 Pro-Touring C-10 5.3L / 4L60E Project Ironhide: 97 GMC Crew Cab 4x4 Cummins SOLD: '69 GMC 1/2T SWB TBI'd: Project No Buck Assembly Manual Index Sign up Thread!!! Factory Service Manual Index



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