Originally Posted by countrygent

I have always had problems with not the best braking on my 93 350. My buddy who used to work in Dodge parts at the time said they had sold a number of the pro-valves. I replaced the master,booster, front stuff and rear stuff. Being old school and finding out as you did, not available on the pro-valve or ABS unit. NOTE: that is one thing you did not mention. When bleeding, you need to bleed the ABS unit before the rear shoes. ANYWAY, I gutted the ABS, took off the pro-valve and installed a manual proportioning valve from SPEEDWAY AUTOMOTIVE. Being a disc/drum system they say to install a 10psi residual valve in the line going to the rear and a 2psi for the front discs, also from Speedway. This is stuff rodders use on there vehicles. Got a good improvement and I can get under the hood and adjust how much braking I want up front. PURPLE THINGY-Man. Pro-valve, BLUE THINGY-2psi residual valve. 10psi valve mounted in the rear. THIS IS OF MY OWN DOING AND NOT TO BE GOSPEL. Take it or leave it. I would say if you went the bone yard route, places like Barely Used Auto parts, could tell you the interchange of the part. I would guess that a 250 and a 350 might be different because of the weight of the vehicle. Maybe not.

Originally Posted by Jacob Phillips

Anyone know where that vacuum line off the booster that goes out of the picture actually goes to? I know the main one Joe's to the vacuum pump another to the module under the master break cylinder but where does that one that leads to the fender connect to

Originally Posted by pigeonman

Yes at times the pedal seems firm . But a lot of the time it feels like the master cylinder is bypassing and the pedal sinks away . Or a spongy feel like air trapped in a line . I've bled with a partner and with a pressure bleeder , got good stream of fluid at all wheels . Have followed the procedure to a T and bench bled master on bench and cracked fittings all the way down the system to bleed until I get to the bleeders . And yes I bled the RWAL first . I never get any air out either after the initial bleed out . I dont know if booster will hold vacuum for a complete hour , but has good vacuum and new check valve came with the booster . It seems to be working good .

In all my years wrenching I've never seen a bad proportioning valve to be honest and it seems like it would just effect bias to front and rear wheels NOT make pedal spongy ....... but theres not much left to try . Has anyone here had a bad one ..... what were the symptoms ?

I did check pushrod clearance at M/C to booster too . Even added some clearance to be sure piston is returning all the way . And I push in that pin on back of the proportioning valve too when I bleed .

Appreciate all comments , I figure with all you Dodge truck owners someone has been through this before and I'm at the right place .

Things like this make you hate being a mechanic

Thanks again !

Bob