Ok, got my engine runnig better and cooler, but i have poor brakes, this isn't a vacuum problem, I had a 94 caprice master cylinder and combination valve from a disc brake car, reason is i have a 9 inch rear with currie explorer disc brakes, and future plans to use the caprice spindles with iroc 12 inch front rotors, my factory combination valve was too close to the headers, so i rerouted those lines and went with the caprice setup, On the first drive i couldn't lock up the brakes on gravel, but when bench bleeding the mc it pushed in easy, got a different one from parts store, that one leaked before i could even put it in car, put the mc that came with the regal in the car, me and the brother in law have been working on getting the air out of the system, the back brakes bleed like normal, pump em up and when you crack the rear fitting the pedal goes down and shoots out air, and now only fluid. The fronts are giving me a headache, we pump them up, and when the fitting is cracked we only get a 1/2 to 1 inch of pedal travel, and it does not shoot air and fluid out, bent up some new lines and tried it with out the combination valve installed, that didn't help, we also removed the mc and bench bled it, that didn't help, pumped brakes up and cracked different flare fittings to look for air bubbles, that didn't help, no matter what we do we can't get decent pressure to the fronts, is this a mc problem? its not new but it worked fine when i bought the car with the v6. I know this is long but if anybody has an idea? The car has only been driven 2 times but it goes really good, I just want to get this fixed and put insurance on it and drive it. I do have a wilwood adjustable prop valve in the rear line, but for now it is set up to not restrict any fluid, we did try it with the valve turned out to reduce rear pressure, but that did not help the front problem. Jon
Hi! When you made new lines are they the same size as original? Does the "new " proportioning valve plumb in the same as the original? I noticed with mine the system has a sort of safety built in that if you blow a line you will always have a front and rear brake that works. I'm no expert or anything but if the only thing different is the caprice p-valve maybe thats the problem? I have a 93 caprice ( wife's car) and it has anti-lock brakes maybe the p-valve will only work with a anti-lock system? In mysetup I used a p-valve from a 80 trans-am with rear disc brakes it bolted in just like the original. And so far no problems? Mind you I've only driven it a few times before the shifter kept sticking in 2nd( new shifter on order) It did stop a lot better than the stock tiny brakes!!! A tip when you get the caprice spindles if you get the right year they came with 4.75 bolt pattern pre-90 Also check out the post on tubular a-arms it will help! Hope that helps? Brad
Hey, the lines I made were 1/4 in the front and 3/16 for the rear, same as original, the new valve is located under the mc, it has a bracket that uses the two bolts for the mc to the vacuum booster, I thought the proportioning valve was my problem, but when we removed it and tried to run the lines direct to the brakes the fronts would not bleed right, its been a headache, I have the caprice parts from a 94, and the rotors are so scratched and rusty that i was planning to buy the iroc ones next year when i could afford the new upper a-arms, i know it means doing all this twice but i figured i would be able to drive it for this summer with the stockers in the front. I could look into using the 80 trans-am piece, but am not sure it will help me after we ran lines without the prop valve in place, thoughts?? Thanks Jon
I'm pretty sure the front lines are 3/16 not 1/4? Its 1/4 from the p-valve to the rear splitter then 3/16 again. and 1/4 from master to p-valve. If thats not a typo that could be your problem! As far as the uppers go did you check out www.ubmachine.com I ordered them Itwas $130 if I remember right ( for the pair) You will need 7 1/2 long not 8 like stock is. Thats what I did worked great! I work as a tech inspector at a local Nascar sanctioned track and we have been using them for years at more speed, heat, and contact than you will see ( hopefully!) on the street. You can order what you want! "Tony" is the guy I dealt with there. Brad
I ordered some parts today, new mc from napa, and new 80 trans-am prop valve from local chevy dealer, hope they are here by next weekend, I will check on those lines tomorrow, if they are backwards then i am gonna be mad at myself, i'm working nights this week and don't always get alot of car time then, Maybe it will be driveable next week, On those upper control arms, are they the same as the global west or hotchkiss replacements, i think they get around $550 for those, if they work I will be calling UB next year, that is a heck of a price drop. Jon
Make sure the p-valve is from a rear disc brake TA! That was an option rear disc brakes I mean. The UB Machine a-arms I like better #1 price #2 I can use what ever ball joint I want #3 I can order the lenght I want. and #4 with headers you will need all the clearance you can get, and I believe the UB Machine a-arms are smaller at the bushing ends! But you can't beat the price! Really when the ball joint get worn I will probablly through out the whole assembly and get new ones! On the master stock have a 1/4 and a 3/16 line on it. I have 2- 86 regals on the stock one the big line goes to the front and the smaller one goes on the back, but on my 455 regal I used a master from the same 81 trans am( as well as the p-valve) and its the opposite? big to the back and smaller one to the front? Now you got me thinking? The brakes worked Ok though? I bought a used one (p-valve) off e-bay as the Gm dealler can't get one so I had to go to AC-Delco and it was over $200! The master was only $60 or so from my local jobber. The only problem I have is the master reservoir is on quite an angle but it still works and I havd to very slightly hammer the hood bracing as the resorvoir handle was slightly touching! I used my sons plastercine to check clearances. Just shut the hood and measure the squish! Hope that helps! Brad
Brad, thanks again, you have been helpful, I took some photos of the engine compartment before i started to do any work on the car, they show the 1/4 line in the front, I told the parts guy I needed the valve for a 4 wheel disc car, it was less than $200, but not much, hope it gets here soon, if all else fails i can talk with local mech, i think he has a monte ss, he would probably let me look at it to see where the lines go, i have a 79 regal that I have robbed a few parts off, that one has the cast iron master and small resivor on top, can't remember for sure but i think that had the 1/4 line in the back port, those ub a-arms sound really good, i will call them when i am ready to do the swap, thanks Jon
