What Are Residual Valves ??

My '30 Model A has a coiled up tangle of steel (I think) brake lines running here and there under the car, connected to a frame mount master cylinder under the floor, and going back to a proportioning valve over the rear axle. One side goes to the drum brakes on the Camaro rear end, the other to the Chevette discs up front. While researching new components to neaten (and safety) this mess up, I read about 2# and 10# residual valves needed for under floor master cylinders. OK, what are they, and what do they do ?? The car seems to stop fine now, tho' I haven't really hit the brakes yet - I'm afraid to in this junkheap.

Up to my ears Lar.

Residual pressure valves hold the minimum pressure required on either the front or rear brakes by preventing flow back to the master cylinder. They are usually used where the master cylinder is located below the level of the wheel cylinders to prevent this flow back to the master cylinder in order to provide full brake fluid to the wheel cylinders/calipers. All drum brake (4 wheel)master cylinders usually have these built in. Stock disc/drum setups may use a combination valve to provide the residual pressure and proportioning.

OK, thanks, now how do I tell what I've got ??

Lar.

If they are Willwoods, 2lbs are blue and 10lbs are red.

These aren't Wilwoods, and no residual valves are visible. How do I tell if they're inside the proportioning valve or master cylinder ??

http://www.ecihotrodbrakes.com/brake_facts.html

this might help :cool:

That's a good'un. Thanks. It's going on my favorites page.

Lar.

eci and masterpower brakes both have good imfo on their web page. they explain what each component of brakes does. if you have to pump them they dont have rvalves.