Thread: Residual Pressure Valve

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Correct me if I'm wrong - you don't need it for firewall mount

Originally Posted by firebird77clone

Correct me if I'm wrong - you don't need it for firewall mount

As a general rule, but drum brakes might be helped by one. The return springs on drums can force the shoes back away from the drums. This can cause additional pumping to get the shoes out where they need to be. Doesn't always happen, but it can. Disc/drum master cylinders usually come with residual valves in the rear circuit under the brass seat in the rear fitting. Disc brakes don't have return springs so it's not an issue.

As to the OP question about double flares. Yes, never use single flares on brake lines, unless you're using the 37* AN fittings. The double flare is intended to reinforce the flare, the AN fitting uses a machined sleeve to do this.