The under frame disk/disk booster i have should have a built in proportioning valve BUT i'm not so sure . Even if it has one built in would it hurt to add a adjustabe one ? If so what brand should i get ?

 

Is your brake system completed now? Can you drive the truck? If so, the test would be to hit the brakes and see if the disc brakes on the front are working before the rears. Try it in an open parking lot because if the booster doesn't have the proportioning valve, the rear end will start to slide to one side because the rear brakes are not working. An adjustable proportioning valve is needed. Speedway sells them. They sell quality products so I would trust them. Summit sells them as well as many other suppliers. Just don't buy an off brand. The valve on booster ( if there is one ) is preset so adding another one will change the pressure ratio. Hope that helps.

 

I am using an adjustable proportioning valve from Summit. It is made by Stainless Steel Brake Co. I have front disc and rear drum brakes. I works very well and I am satisfied with it

 

Thanks guys !!! I have new everything on my truck but i can't power brake it cause it just won't hold it back and with 4 wheel disk you would think it would .So something ain't right. I have good brakes but they could be better.

 

Sorry for being stupid but what does "I can't power brake it because it won't hold it back" mean ? Should be same pressure to all corners if it's all discs. Maybe I'm wrong,(not the first time)but the whole idea of a proportioning valve is to balance difference in pressure needed for a drums in the rear and discs up front. I can't see what purpose a proportioning valve would have in a four disc set up. It should stop on a dime with four discs.

 

LOL power braking is you keep the front brakes locked while you break the rear ones loose for some really great smoking burnouts!