Power Brake Setups?

[tomfg]

Have drum brakes on the front and rear of my 64 Chevy 1/2 ton.
I want to purchase a power booster brake set up, but just as soon buy the disc / drum master cylinder/ booster setup, in case I decide to upgrade to front disc brakes.... if this setup will work on my all drum brake truck. I talked to the folks at Brothers.com, and they say their disc / drum booster will work. All I have to do is remove the proportional valve. Otherwise they say that the disc / drum setup has a bigger reservoir than their drum / drum booster setup.
Does anyone know if I'm going to have any problems, ie., stopping, if I use a disc / drum setup, on my drum / drum truck?
Thanks, Tom

[Seon]

What Brothers said sounds about right. The proportional valve is only used on front disc/rear drum set up. If you use it on a drum/drum, you won't need the prop. vlv. It'll work as a regular power drum/drum brakes.

[tomfg]

Thanks for your reply. Have since read the following on
http://www.mpbrakes.com/mpfaqmasters.htm
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A drum brake master will differ from a disc brake master in two ways. The amount of fluid that a drum brake master has to move is less than disc brake. Drum brake masters have 10 lb residual valves at the outlet to keep a residual pressure on the drums. If you use a drum brake master for disc brakes you would move an insufficient volume of fluid and the disc brakes would drag because of the residual valves.
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Not having this residual valve for my front drum brake while
using the disc / drum setup might be a snag...... not sure, but I see you can purchase "in-line" residual valves... would mind,
but would like to know if the whole thing is going to work if I spend the money. Any further input grateful. Thanks, Tom

[GSFMECH]

tomfg,

Check out 65streetcruisers 65 pics posted yesterday on the 67-72 message board. We scavenged that booster/master cylinder setup off a 71/72 truck. The booster will bolt up to 2 of the holes but you will have to drill out 2 more as the booster is attached with 4 bolts. If you go this route you will have to fine tune the rod length between the pedal and booster to get proper travel, if I remember right we cut the head off a fine thread bolt and made our own rod and kept trimming it until we got it right. We used the proportioning valve off a 72 truck also as we used disc brakes (off a 71). Heres the interesting twist. The single pot master cylinder for the drum brakes that you have now, will pysically bolt up to the 71-72 booster ( I have went the other way using a twin pot master cyld. bolted to the firewall w/ prop. valve f/ disc brakes). The only unknown is if the rod length on it would be right. It could be an option for you if you wanted to keep the drums for awhile longer and wanted to change to disc later. If it could be made to work you could run it as is ( with the booster) and later on replumb for the disc. setup. The change to disc brakes is not hard, I have done it several times with and without the booster. If you go 71-72 as the doner it is paracticaly a bolt in.

Mike

[cochran63]

on my 63 c-10 i used a brakebooster from a 76 corvette. it bolted up to my existing holes. I have 4 wheel disk brakes, so it may not work for your application. I will try to get some snap shots of it tomorow.

[cochran63]

Here is an older pic of my brakebooster setup. checkout the custom heater hose clamp.

[ShamrockCustoms]

you should be able to use a power booster for disc/drum on a drum/drum system. you only really need the residual valve if mounting the unit under the floor. should still use the proportioning valve (ie like a wilwood type) for the rear drums to keep from locking them up. if changing set-up, should go ahead and get the front discs same time as booster, less work overall to just do it all at once.

good luck!