The Stovebolt Site Forums The Shop Area General Truck Talk UPDATE: 1958 Chevy Drum to Disc conversion.

I would put them in if it was my project.

They're cheap enough I would too. ...and am.

So are these put at each wheel? How would you proceed?

Deve: Search the internet to at least get some education on residual valves or these posts will last forever. It's mostly been explained by the other kind posters here on this thread. Like myself, on 17/01/14 12:14 PM. Two weeks ago. 10 lbs and 2 lbs as Alvin said, they are brass or aluminum looking fittings screwed right to the prop valve if you wish. One handles both fronts and the other handles both rears on a disc/drum setup.

I don't want to take the long way around this issue. I just want to know what others doing this same upgrade are using. One for the front and one for the back? One for each corner? Part numbers for each? Stating these facts will help the next guy too, not just me. There is no room near the prop valve, so I am hoping they are inline and can be used in a more convenient location. I just want to know what works. Thanks!

Deve, when I did my brakes on the 52panel I knew I'd most likely end up with disc on the front. I went ahead and put the 10lb residual in line about mid way the chassis rail. I will put the 2 lb on when I do the disc.

Whether its OK the way I did it I can only attest to how mine works as it is right now. On two occasions I've already had to "stand on the brakes". I mean I had to get on them. WHOA, the panel stood on its nose. I was not ready for that. I run a 7" booster with dual master cylinder. Did that help?...probably. Did the 10 lb residual valve help?...probably. One thing for sure the panel has darn good brakes on it.

....would the current set up hold up coming down Saluda Grade
(big steep grade near by in the mountains) while riding the brakes? I doubt it but not many will...even disc if you ride them enough.
For now I'm happy. If things continue to run good I may NOT put disc on it....its not a hot rod like my 37 but the 37 has disc.

From Family Feud, (The beaten to death episode): Survey says! "Chevy and the rest of the manufacturers used residual valves in the drum brake lines from forever. In the early years they were in the master cylinder outlet port. Then with the advent of front disc/rear drum they moved the residual valve to the combination valve" (proportioning valve). Provided everybody knows if their kit has built in residual valves or not and we are talking Disc/Drum.... Line from one master cylinder reservoir goes into the designated prop inlet, the other line from other res goes into designated prop inlet. The prop has three outlets, one for the rear brakes and two for the front. If the prop outlet for the rear is facing rear, you can put residual right there (10 lb) and on to the rear "T". Choose the best of the two available front outlet locations on the prop (2 lb) and then to the front "T". or if you are a contrarian, you can put the residuals inline before the "T"s. Don't forget, you can use 90 deg or 45 deg ells out of the prop to facilitate clearance. You can run a separate line out of each prop outlet to each front wheel but that would be silly now wouldn't it.

CPP website sounds like y'all get a residual valve included for rear.
INSTALLATION NOTES:

• On Disc front, Drum rear combinations with a single master cylinder, be sure to remove the residual check valve, or purchase a master cylinder without a check valve. You must then install an in-line residual check valve in the line to the rear drum brakes. The valve should be installed on the brake side of the proportioning valve as shown in the diagram.
• When using a dual master cylinder with Disc front, Drum rear combinations you won't need to remove the residual check valve as it only applies pressure to the rear brake line. On dual master cylinders, the large reservoir side is for the disc brakes, and the small reservoir side is for the drum brakes.
• Do not use a residual pressure valve with 4 wheel Disc brake systems. The residual pressure will cause the calipers to drag.
• An adjustable Proportioning valve allows you to balance the pressure between the front and rear brakes for smooth safe stops. This is a must for disc/drum combinations, as disc brakes require considerably more pressure to operate than drum brakes. Without a properly adjusted proportioning valve, the drum brakes will lock up before the discs do which can result in handling problems. Proportioning valves are also useful on 4-wheel disc or 4-wheel drum brake systems, giving you the ability to compensate for tire size differences, weight distribution, etc.
• Make sure that the bleeder valves on the calipers and the power booster point up when installed. Air cannot be fully bled from the system unless the valves are installed in the up position.
• If you do not intend to use a power booster, we recommend that you use a dual master cylinder.

And while you are wondering about your vendor's kit, here is a good read from....again, CPP's website.
http://www.classicperform.com/Instructions/PDF/CPPbrakeguide.pdf

So really its okay to put these inline valves anywhere before the front calipers and anywhere before the rear drums? Anyone who orders these, let me know what you ordered.

Most of the instructions I write, I include part numbers. It removes a lot of ambiguity and concern which makes it more possible for the new guy.

I am sure using the right residual valves cant HURT the system?

Put the residual valves as close to the master cylinder as possible.

Having the right residual valves will help your pedal feel and braking performance. They're different than a proportioning valve though, different purposes.

I love a disc brake conversion.
dual master only. dont fart around with your OEM single-not safe.

on my 52 I did a master only home made setup (back in the 90's) and used a master from Nova(new) that had 1" bore.
used a combination valve from a 76 camaro(same weight and same balance ratio)
5 lug disc conversion on straight axle

loved it and it worked flawlessly.
--

on my 52 panel i did a master from 70's chevy truck and booster from 71 ford 3/4t 4x4 which is a 7" dual diapfram booster.
too much boost.
dont do it.-will slam you through windshield. =)
also did the camaro combo valve. not enough juice going to rear brakes-should have found combo from maybe a suburban or wagoneer or something like that with more 50/50 ratio.
never a stopping issue though. EVER! I can out-stop any car i have ever driven.(camaro front clip)

combination valves required on any conversion.
combo valves have proportioning valve which decides how much power goes front or rear and the ratio.
they also have residual check valves which are required for all systems.
discs like about 2# pressure and drums have harder springs and like about 10#.
if you only use proportioning valve(ratio) your pedal will sink low and/or double pump to stop to overcome the springs which have pulled shoes away from drums.

i like to buy from rockauto.com or napa for master/booster so that i have OEM type part number for replacement. CPP is GREAT company but I dont want to have to reply on them for master replace when I need one.
I goto pick/pull for combo valve.
dig around in a NON-ABS car like 1981 and earlier.
just take those dikes and kink/snap brake lines leading to valve which may be mounted by booster or down by frame rail.
I stick with chevy and if a truck any nova/camaro/skylark... will work.

This is my first one, and thanks to everyone here, I am learning a great deal. Barts research on CPP should help anyone trying to do this. Moral of the story there is, go to the websites, don't just rely on what comes in the kit. NOTHING.. not even.. "for more information go to our website".

Many people my age have no idea how to navigate the internet, and some don't even have a computer. I have a printing customer that still uses his Apple 2E and wonders why I have to re-scan hard copy into our system. I, on the other hand build my own computers and consult on larger business networks being A+, Net+ and MSCE certified. And I HATE going to websites for information I feel I paid for dearly in purchasing their kits. It shows a lack of concern for the customer who may or may not be internet saavy. If they would have a little card in the kit.. on the card it says.. "hey dumass! If you cant figure this out, go to our website!" then I could at least laugh about it.

So, my questions are.. is there ANY difference physics-wise in where you put these residual valves (within reason) like on the frame rail near the rear, or near the front as opposed to near the prop valve? Since these are inline tubular units (I imagine but I haven't seen anyone post examples yet), or is there a good reason to keep them near the MC and prop valve? I will write a how-to on this and make it very clear so people like me don't have to wrestle with it.

Also, since from what I understand anyway, the purpose of the residual valve is to keep the fluid from flowing backwards causing a squishy pedal, my original question still stands, which, once again, is.. If I have a proportioning valve directly under the dual MC, the MC is 3 inches higher than the top of the calipers, the prop valve about 1 inch above, what is the impact of the prop valve in keeping this 'backfill' phenomenon from happening? From what I read in the CPP documentation, I still don't know.

my original question still stands, which, once again, is.. If I have a proportioning valve directly under the dual MC, the MC is 3 inches higher than the top of the calipers, the prop valve about 1 inch above, what is the impact of the prop valve in keeping this 'backfill' phenomenon from happening? From what I read in the CPP documentation, I still don't know.
This is the answer once again in a different way. Repeat, this is the answer to the above question. The answer to your question is as follows: Answer; Prop valve has no impact on the phenomenon, which is not a phenomenon, just gravity. Furthermore: It is advisable, but not mandatory, to put the residual valve (s) close to prop outlet. They are a one way check valve and up stream fluid (towards the wheel cylinders)is kept from flowing back because the valve is closed in that direction. I believe down stream (towards prop valve)is kept from flowing back do to the phenomenon of finger over end of a straw principle. The lines become charged/pressurised by pedal and all stays pressurised using these R-valves, thus not allowing the springs/rods/piston to "pull" back on the shoes as much as without them. The pads have no springs and therefore just relax after pedal is released and don't move very far away from rotor. All experts say you need one for the drums because of the pesky return springs and half of the experts say put one on the discs. Put them ANYWHERE before the "T".
If you do not like the internet or searching websites or using the web as a great resource, you will be at a great disadvantage in your hobby. But there will always be someone here that will look it up so they can learn. I don't know all this crap, I look it up, think about what I read on the net, what I read from the stovebolt and use what little I know and try to give a correct answer...albeit several times.

So, now that I am an expert, Alvin, can you see why its not best practice to put the residual valve on the frame rail? All of the fluid from the frame rail to the drums (or discs) is kept in place, but the fluid before the residual valve to the MC is subject to backflow. So to me this would not be a good thing at all because it could result in the squishy pedal you are trying to eliminate. Without Bart and the way he likes to humiliate his victims, where would we all be? Nonetheless, I get it now, so thanks? If I decide to install residuals, once I figure out which ones to get, I will put them as close to the MC as possible. To find an incline high enough to park my truck at the angle for this to matter, I would have to drive about 300 miles living in central Kansas and all.

If I were you I would not put any on your system. It will only be useful if you drive your truck.

The plan for this truck is to drive the crap out of it. I am even thinking of a few cross country missions. If its something I need, I need to put them in. I love a good trailer queen as much as anyone, but I just feel a truck is meant to be driven.

This thread has run it's course. A lot of it is duplicated here.