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79loserbluebu
04-01-2015, 06:41 PM
Hey guys, need help figuring out which would be the best path to take for my car. It's a 79' Malibu, and I'll be using LS1 front and rear brakes. Plan on using a S10 master cylinder from a 98+ truck as its the look that I want under the hood and it has the same specs as the gbody master cylinder. I am also running the factory brake booster.

Basically all I'm having difficulty with besides the swap is how to plumb the brake system the best way. For now everything is sitting factory, but I'm undecided which way to go as far as proportioning valves. I would like to keep the top looking the way it does and not have a valve mounted next to the master. So I'm thinking maybe modify the factory valve and run an adjustable at the rear line? Or do I purchase a disc/disc unit from the various vendors and then add the valve to the rear?


Also, how much do I remove from the factory valve? I have seen posts with people taking plungers and springs out and I have seen the CPP instructions that say disassemble and remove the small rubber piece?

79loserbluebu
04-01-2015, 08:55 PM
Sorry guys, I think I am overthinking this way too much. I've looked up a valve that I had laying around my garage and it is listed as disc/drum, but used in popular disc/disc kits. So I undid the plug on the rear of the valve to dissect it, and it looks like this picture except not taken apart. So should I just put this valve in, and if needed add an adjustable down the road?

110918

andrewb70
04-02-2015, 06:53 AM
Sorry guys, I think I am overthinking this way too much. I've looked up a valve that I had laying around my garage and it is listed as disc/drum, but used in popular disc/disc kits. So I undid the plug on the rear of the valve to dissect it, and it looks like this picture except not taken apart. So should I just put this valve in, and if needed add an adjustable down the road?

110918

Is that a prop valve built in or just the plunger for the brake warning switch?

Andrew

rrelco
04-02-2015, 07:35 AM
get a wilwood adjustable prop vale and be done with it...most of us here run those

79loserbluebu
04-02-2015, 05:47 PM
Its just the plunger and that piece isn't supposed to come out like it did in the picture.

I bought the wilwood combination valve with the adjustable for the rear but don't want to have to redo my lines for that. Unlike the older cars the gbodies have a frame mounted prop valve and the lines aren't even close to the wilwood

Today I just bought a cheap summit unit I guess I'm going to run the valve like the picture above and plumb in this adjustable one and see what happens

Apogee
04-09-2015, 03:19 PM
...Today I just bought a cheap summit unit I guess I'm going to run the valve like the picture above and plumb in this adjustable one and see what happens

The combination valves based on the 1971-1977 GM units are available in either disc/drum or disc/disc variations. Both units have fixed proportioning valves in the rear circuit, so if that's what you're going to run, then do not run another proportioning valve. You never want two proportioning valves in any given brake circuit, as the results can be no bueno and unpredictable.

Tobin
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