Placement of residual pressure valves

[Dennis Detweiler]

I just installed a disc brake conversion on my 39. My single reservoir master is a year old, so going to pull the valve from it and use it. I want to install a 10lb valve for the rear brakes and 2lb for the front. I couldn't find a diagram for brake lines and valve placement for a single reservoir master on the internet. If I recall correctly, the line from my master runs to a block toward the rear, then lines back to the front brakes and rear. Anyone have a diagram for the conversion using the two valves?

Is the emergency brake (band around the driveshaft) efficient on these old cars? I never tried using it while the car was moving.

[Plymouthy Adams]

somewhere you have a T for your single reservoir master..place the two pound inline with the single feed before the line splits to each front caliper and the 10 lb inline to the rear prior to the T connector that is the rubber hose inlet at the axle.  do keep in mind that your brake light switch if hydraulic that it is not affected by the residual 10...should not be that sensitive but just be sure first...

[Adam H P15 D30]

Try it without the valves first.  I ended up not needing any after I pulled the internal one.

[Plymouthy Adams]

the use of the residual is very important, its purpose is to keep just a tad of pressure on the piston cups and to prevent all the fluid returning to the master, keeps fluid form leaking out of the cylinder when idle and even more important, air from leaking in.  IF your cylinder is one of a design that has spring style cup expanders, one could do without the residual valve.

Edited August 2, 2018 by Plymouthy Adams

[Dennis Detweiler]

Do the front discs actually need the valve? If I only use a 10lb behind the T going to the rear drums, will that be sufficient?

Scarebird just says, remove the valve from the single reservoir master.

[casper50]

I removed the valve from mine but I put all 4 discs in.  Works fine so far.