Can this be done?

[Roger D.]

Maybe I'm crazy for asking but.....

On a '72 350/200 Auto coupe, can the brake lines going from the proportioning valve to the rear calipers along the chassis be replaced with the body still on the car and still be NCRS correct?

Has anyone ever successfully done this?

Thanks in advance.

Roger

[Patrick H.]

Re: Can this be done?

Yes and yes.
Be thankful it's not a 4-speed.

I've done an auto before and am about to do a 4 speed. At least with an auto you can partially remove the trans crossmember and it's a piece of cake. With a 4 speed, not so much.

Patrick

[Phil D.]

Re: Can this be done?

Patrick a follow-up question. I assume you did it using a pre-bent unit out of one of the Corvette catalogs and not a "from scratch" coil of tubing. And I think I read somewhere that even the pre-bent units are shipped somewhat coiled up, is that right?

Phil

[Kenny C.]

Re: Can this be done?

Not coiled but bent in half.

[Terry M.]

Re: Can this be done?

A minor technical (after all this IS a tech board) point: Your Corvette does NOT have a proportioning valve -- unless you or some other person added it.

Your Corvette does have a differential pressure/distribution block mounted on the frame just in front of the steering box.

[Roger D.]

Re: Can this be done?

Thanks for the replies. I guess the real hitch in the plan will be if I break off one of the brake line mounting bolts...after all I have no reservation in saying that they have been in there since original manufacture. There is surface corrosion and rust and drilling out a broken bolt would be near impossible...hmmm.

Terry, I looked on Bair's and Zip Corvette websites and they call it a proportioning valve. On Corvette Central, they called the same part a distribution block. I looked in the AIM manual and they give it GM P/N 3980797 and call it a Switch ASM. I'm good with calling it a distribution block too.

[Patrick H.]

Re: Can this be done?

Patrick a follow-up question. I assume you did it using a pre-bent unit out of one of the Corvette catalogs and not a "from scratch" coil of tubing. And I think I read somewhere that even the pre-bent units are shipped somewhat coiled up, is that right?

Phil

Yes, the sort-of-prebent units from the Corvette catalogs.
Far easier to install than a fuel line, though.

Patrick

[Terry M.]

Re: Can this be done?

I suppose differential pressure switch is the proper name, but it also serves as a distribution block. It is often incorrectly called a proportioning valve (in common conversation and on this site), but I would expect Bair's and Zip to know better.

[Kurt G.]

Re: Can this be done?

Been there, done it, got the t-shirt. When you do it, replace the clips also. I agree with everyone else, pre-bent is the way to go.