'79 Suburban brake proportioning valve - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jimfulco · 02-09-2009, 12:22 AM

'79 Suburban, half-ton, 2WD, gas engine, 260K miles. My proportioning valve seems to be leaking from some kind of opening underneath a hexagonal fitting on the far right side, which feeds the rear brakes. There was a tiny (~1/4" diameter) star-washer looking thing and a rubber thing in the hole. I can't imagine a tiny rubber doodad holding back hydraulic brake pressure for 30 years, but it just recently started puking fluid all over the place. Any idea what this opening is supposed to be for?

**N2TRUX** · 02-09-2009, 11:45 AM

Anyone?

menace121978 · 02-09-2009, 06:52 PM

pics would help buddy... i replaced mine a few years back. was leaking from rear brake lines/proportion valve also. just kept getting worse and worse till i had to fill up the rear resevoir every week.

jimfulco · 02-17-2009, 09:13 AM

It's leaking from under the black rubber thing on the fitting on the right side of the pic. Nobody in town has the valve, not even the Chevy dealer. I need to know what the purpose of the black thing is so I can decide whether or not I can plug it with something and get the truck back on the road.

02-09-2009, 12:22 AM	#1
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	'79 Suburban brake proportioning valve '79 Suburban, half-ton, 2WD, gas engine, 260K miles. My proportioning valve seems to be leaking from some kind of opening underneath a hexagonal fitting on the far right side, which feeds the rear brakes. There was a tiny (~1/4" diameter) star-washer looking thing and a rubber thing in the hole. I can't imagine a tiny rubber doodad holding back hydraulic brake pressure for 30 years, but it just recently started puking fluid all over the place. Any idea what this opening is supposed to be for?

02-09-2009, 11:45 AM	#2
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	Re: '79 Suburban brake proportioning valve Anyone? __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

02-09-2009, 06:52 PM	#3
menace121978 Registered User Join Date: Jan 2009 Location: orangevale, ca Posts: 3,626	Re: '79 Suburban brake proportioning valve pics would help buddy... i replaced mine a few years back. was leaking from rear brake lines/proportion valve also. just kept getting worse and worse till i had to fill up the rear resevoir every week. __________________ "Dennis the Menace" 1978 Silverado (2wd, 1/2 ton, short bed)complete nut & bolt frame off restomod LQ9/4L80E MY LS SWAP/FRAME OFF BUILD BOOK 2006 TBSS way too much to list

02-17-2009, 09:13 AM	#4
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	Re: '79 Suburban brake proportioning valve It's leaking from under the black rubber thing on the fitting on the right side of the pic. Nobody in town has the valve, not even the Chevy dealer. I need to know what the purpose of the black thing is so I can decide whether or not I can plug it with something and get the truck back on the road.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.