Mike H.

I'm plumbing the lines for a front disc set up and a line-lock in my '68 Cutlass. I plan on running the front brakes lines in this order:
Master Cylinder - Proportioning Valve - Line/Lock - Distribution Block - Caliper

My main concern is, will it be OK to use the stock distribution block.

Thanks for any help or suggestions.

Mike

oldcutlass

Like this?

http://www.hotrod.com/howto/49619_br.../photo_01.html

69442C

The original distribution block, assuming you are using the factory original or original replacement one for a 68 Cutlass/442, will be fine as it is just a distribution block. It serves no other purpose than to send the fluid to the calipers or wheel cylinders. For 68-70 A body cars, the distribution block was the same for 4 wheel drum or front disc/rear drum. If the car did get front disc brakes, a hold-off valve was installed up near the master cylinder to slightly delay the fluid going to the front calipers. You want to place the line lock on the line that supplies fluid for the front brakes and locate it between the hold off valve and the distribution block since that will give you the most space. It can go between the MC and the hold-off valve too but there's not a lot of brake line to work with between those 2 points.

Brian

ah64pilot

This will give you an idea.

FWIW, I put the lock between the MC and proportioning (combination valve on my car) so that when the line lock is engaged it turns on the "BRAKE" warning light in the fuel cluster. That kept me from having to mount an external warning light.

Mike H.

Guys,
I appreciate all the feedback. It all helped tremendously. Nice suggestion on the light detail.

Thanks, Mike

Run to Rund

The type of proportioning valve I used in the mid 1980s was the Mopar adjustable and was intended for the rear brakes, not the front. At the front I would then use master cylinder-line lock-distribution block-front wheels.

joe_padavano

Yup, since the differential pressure valve in the distribution block is now sensing a difference in pressure from the front to the back brakes. This is no problem so long as the valve spool doesn't get stuck in that position. That can sometimes happen if there's sludge in the distribution block (it's brass, so it doesn't rust). If the light does stay on, it means that the spool got stuck and you won't have working back brakes.

Note that this is potentially a bigger problem for 1971-up disc brake cars with the cast iron combination valve. That one DOES rust internally, increasing the potential for the spool getting stuck.