Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Anyone tell me what engine & tranny this is?
View Single Post
  #89 (permalink)  
Old 10-31-2012, 08:36 AM
cobalt327's Avatar
cobalt327 cobalt327 is offline
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 598 Times in 547 Posts
Quote:
Originally Posted by PRHeloPilot View Post
Are you kidding me? No need to apologize for anything. I'm so grateful for everyone's help here it's not even funny !!

I looked up the Raybestos MC #39052 and JC Whitney has it for the 1980 Corvette. They also have the Cardone for the same car and it's the same part# as the one I previously found for the '79 Corvette so I'm in luck because O'Reilly's website says they have it in stock in all of their stores around here. It must be a popular MC.

Found the PV-4 here. Haven't found it anywhere local but I'll keep searching

74-96 Chevy/GMC Workhorse "P" 1 Ton JF9 Type Van Front Disc/ Rear Disc Proportioning Valve at Carolina Classic Trucks


.
Because the stock type combo valves are not adjustable, finding a combo valve w/the right front-to-rear brake bias to match what your truck needs might not be so easy.

So what you might want to consider doing is disabling the combo valve's proportioning function then adding an adjustable proportioning valve.

The reason for disabling the combo valve's prop. valve is because if you just add an adjustable proportioning valve to the existing combo valve, you would in effect be adding a prop valve to a prop valve.

That means you would not be able to increase the rear brake pressure beyond where the combo valve is set to. You would only be able to take more pressure away from the rear brakes.

Fortunately on most GM combo valves, you can disable the combo valve's prop valve by unscrewing the fitting from the combo valve that has the rear brake line coming from it, then remove the (rubber or spring loaded metal) valve inside the body, then reattach the fitting.

Then you would add an adjustable prop valve.
Reply With Quote