66 Dual Master

[tera155]

So I have drums all around -- but would like to convert to a dual master. I have read mixed reports about needing a proportioning valve on an all drum master. Any advice would be appreciated. tx, Thad Dupper

[Otto Skorzeny]

I don't think you'll need a separate proportioning valve. Use a mc and booster from a 1969 Toro. The same two parts were used on disc brake cars and drum brake cars.

Here's a thread on this site discussing the conversion. page 2 shows the finished conversion,

viewtopic.php?f=7&t=462&p=1857&hilit=master+cylinder+conversion#p1857

[Doc Hubler]

You do need the proportioning valve. Otherwise rear brakes will lock up when braking hard. The proportioning valve or balance valve delays the action of the rear brakes very briefly. Other than the proportioning valve, you'll need a distribution block up front (these also included a wiring signal to indicate front or rear brake failure, i.e., a leak with loss of brakes either the front or rear brakes. These were standard on all 1967 Toronados onward. THe balance valve changed slightly for 1967, but same basic function. Let me now if you need pictures.

[Doc Hubler]

Here is the picture off my 67. Master Cylinder is off/not in picture. But the lines are connected to the distribution block. The rear line goes through the brass proportioning or balance valve which is attached to the frame. You'll need these when you convert to Dual MC. ON the distribution block on the top center, is the electrical connection for the warning light on the dash (not currently connected to wire).

Brake lines Small.jpg (80.11 KiB) Viewed 7522 times

[Otto Skorzeny]

OK, is the proportioning valve the brass thing in the lower right? Does '66 have one? Can the same one be used with dual mc?

[Doc Hubler]

Otto,

Yes, balance (proportioning valve) is the brass block on the side of the frame that goes to rear brakes. The distribution block is mounted on top of the frame just below MC, and where all the lines connect and go out to the various wheels.

No, 66 was a single MC, and there was only a brass block distributing fluid to all the lines (mounted about where distribution block in picture is). There was no balance valve included either for 66. All those came in 67, after Olds got raked over the coals on the drum brakes (which is pretty much BS anyway as I know you agree). So these were the major changes to the basic braking system for 67, and of course they offered optional front disc brakes. You could take any 67-68 system and it will be essentially the same (part numbers may vary slightly). The 69 had a slightly different design to the balance valve. More modern in appearance I would say.