...my undying gratitude. =]

I cannot for the life of me, figure out what this thing is....
http://www.geocities.com/MotorCity/Show/1818/dunno.jpg

Its part of a complete set of disc brakes I got off a 72 Chevelle. But that was ten years ago.....and I have no clue if this...*thing*...goes with it. Cant seem to find it in the limited literature I have.

Help? Thanks!

I'm not sure of the correct terminology, but it was used to delay the front brake action until the rear made contact with the drums. Call it a proportioning valve, a delay valve, or whatever you want. It bolts to the same bolt as the one that the master cylinder bolts to, on the drivers side. The front line from the master cylinder goes to the valve, then the line goes to the distribution block on the frame below the master cylinder.

Looks like a proportioning valve to me. Used on disc brake cars starting in 67. Mounts off the bottom driver's side of the master cylinder.

Ah see, ah see......hmmmm......great info!
Now I just gotta figure out if I'm gonna use it, or scrap it...
Thanks!

This delay valve was not used after 70. 71 and 72 models had a different setup. They had a combination proportioning valve/distribution block mounted down on the inside of the frame. Someone must have swapped it in at some point.

Bob Murray

The correct term is metering valve. It held off the front brakes untill the back drum brakes could overcome the return springs and contact the drum. After 1970 it is part of the combination valve. Only some used a seperate propotioning valve that was mounted on the frame were the flexible brake line from the rearend connects to the steel line. So far I have only seen some 70 elcaminos with this valve.

I have seen that metering valve on a '71 Grand Prix disc brake set-up. From what I can tell, that metering valve was used with the stock drum brake proportioning valve. Without that metering valve, I don't think you can use the stock drum brake proportioning vavle on power disc brakes and have them function properly. I do think you can remove that metering valve and then just replace your proportioning valve with the disk brake proportioning valve.

Mike is correct in the application of this part. They were used on all 67-70 disk brake cars so that more of the brake lines would interchange between disk and nondisk cars. Brian if you decide to not use this part please let me know I wouldn't mind having it...

FIG

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MCC member #256