[runn141]

i recently sold the rear disc brake rearend from my truck so im now gonna be going back to drum brakes. i had put a 2lb. residual valve in the line for the rear disc. will i have to remove it now for drum brakes?

[LATECH]

Yeah, you will need to take it off and put the disc drum master cylinder back on and the proportioning valve. The proportioning valve (factory one) is for safety only.But it is a good idea to have it on. If one system ( Front or Rear )
Loses pressure ( springs a leak ) the valve inside shuttles to close off that part of the system,keeps air from purging back into the other system and keeps the system that is left functioning.
Aftermarket valves for disc to disc conversion are for regulating how much pressure goes to the rear set to keep from locking the wheels. Front wheel drive cars use a similar thing for the transverse braking system that they use. Manufacturers call it a hold off valve.
The aftermarket valves are nice because you can mix and match without to much regard to balancing sytem piston sizes...pad square inch etc.

[runn141]

i never changed anything to begin with. other than put the rearend with disc brakes in and then put the residual valve in the line.

[LATECH]

then you will be good to go. just remove the residual valve.