I am preparing to begin assembling my new disc brake conversion kit on my '68 and was wondering if I would benefit at all by running a 10 lb residual valve to the rear drums? The kit I got is from True Connections (12" rotor, 2" drop spindle, 11" booster, combination valve). What do you guys think???
Thx- Jason

The answer to this type of question always comes down to the master cylinder itself. Probably not likely with the True Connections kit. If you were using a Wilwood master cylinder then it would be needed.

Thomas

Thx Thomas!

I'm thinking 10lb valves are for rear discs, and the 2lb valves are for drums, if needed.

I think it is the 2 lb valve for disc, and the 10 lb valve for drum, I could be wrong though- It wouldn't be the first time!

If you want, I have a complete set of ECI rear disc brakes with parking brake assembly that bolts on to your car. They were used for under 500 miles. They come with parking cables, brake likes, calipers, brackets, pads & rotors.

I changed directiond and installed Corvette brakes all around. Personally, I do not like drum brakes...

I'll sell you the setup for half the price of new, plus actual shipping. If interested, email me directly.

Theo.

Yes 10lb residual pressure valves are for drum brakes, 2lb residual pressure valves are only required on disc brakes if the master cylinder is one of the floor mounted instead of firewall, so they aren't needed on chevelles. A lot of newer aftermarket Master Cylinders don't have the 10lb residual pressure valve build in, so you have to install one if you use drums in the rear.

"These masters do not have residual valves built in. The only time you'd need a residual valve is when the master is below the Calipers/Wheel cylinders which is near impossible on a Chevelle or El Camino
Thanks
Daniel

www.true-connections.com"

This is the reply I got from True Connections. What do you guys think?

"These masters do not have residual valves built in. The only time you'd need a residual valve is when the master is below the Calipers/Wheel cylinders which is near impossible on a Chevelle or El Camino
Thanks
Daniel

www.true-connections.com"

This is the reply I got from True Connections. What do you guys think?
I think he's right. It's my understanding that you only need the valves if the MC is mounted below the wheel cylinders/calipers. Such as in a street rod.

Jeff

http://www.mpbrakes.com/mpfaqvalving.htm
http://www.mpbrakes.com/typical.htm
What about the pic shown on these pages? Sorry for dragging this out!
Thx- Jason

oh well, thx anyways, I was just curious

Drums need some residual pressure to hold the cup seals against the cylinder walls so they wont be able to suck in air when you release the pedal, at least according to some old hydraulic brake manuals I have access to.