The Stovebolt Site Forums The Shop Area Engine Shop 2# and 10# residual valve

Hey guys, just installed my disk/drum system on my '48 1/2t chevy. Now I'm trying to install the res. valves the 2# went on just great because the line is 3/16 , but the back line is 1/4" and the res. valve (10#red)does notexcept
thatline only 3/16" all of the books I have (CCP,wilwood) say for front disk use a 2#valve with 3/16" line and the rear drums use a 10#valve with 1/4 brakeline.? Im at a stand still. Also if I use a Adj. Proprtion valve do I also use a stock Pro. valve with my dual m/c, or one or the other. Thanx for all your help. I have looked into the old forums but no answer.

Brakes can be complicated and your proportioning valve question could be real hard to answer without a lot more information.

My suggestion would be to use an adjustable valve and know you're going to spend some time getting it set up right.

As for the tubing size, I don't know what book you are reading but those I've read say it makes almost no difference. I'd go with 3/16" line in this case because its easier to buy more line at the local parts house than get a different size residual valve from a mail order vender.

Another possible solution is to buy an adapter, but that adds some more joint that might cause problems later.

Hy bowtiesr4me, I'm afraid I have questions also. First was the master for a disc/disc system or a disc/drum system? If it's for a disc/drum system it should already have a residual pressure valve built in to the rear system. As for the proportioning valve, you could use a stock one, or if you have to have something new you could just put a pressure reducing valve in the rear system, hope that helps.

I bought the dual m/c in a disk brake kit from CCP and the m/c is a 77 corvette, but also I was reading in an old magazine and it said that GM went to all 3/16" brake line later on to save money. Thanx for all your help!!!!!!11 keep up the good work

Wouldn't that be a disk/disk master? You are doing disk and drum aren't you?

If its disk on both ends you want two 2# residuals, and won't need the 10# at all.

I've used the CPP front disc conversion with corvette disc/drum master, 2 & 10 pound residual valves and a Wilwood adjustable prop valve on several vehicles. Never ran into a 1/4" rear line. The little adaptors for the residual valves are only for 3/16th lines.

The Wilwood adjustable prop valve goes behind the 10 pound residual valve in the rear circuit. (Master cylinder to residual valve, then adj prop valve.)DO NOT use your stock prop. valve with the adjustable valve. Normally, 2 turns from fully closed on the adjustable prop. valve is a good place to start tuning your rear brake bias. There is some good info at the following sites:

http://www.ecihotrodbrakes.com
http://www.mpbrakes.com
http://classicperform.com

Be careful with the little threaded adaptors for the residual valves....they are not just something you can pick up locally. You may have to run some new 3/16 line to the rear. Hope this helps.

Dave

Hey Dave (Fla54Chevy3100)Thanx for the help! It answered all of my questions. Thank's to you other fellows also.I do have to run 3/16 line because my '48 had 1/4" but thats all gone now!
Thank You Again, Mike

Hope this can help other folks doing this kind of work ,sometimes you just cannot find the answer in books or manuals.It's great to have folks like the STOVEBOLT GANG to help out !