Posted by rickyracer (IP: 209.20.170.18) on February 27, 2000 at 02:19:11:
In Reply to: No you DON'T... posted by T.L. on February 26, 2000 at 21:52:01:
In case you went around working on cars in 73, they were just starting to really put disc brakes on cars. Mostly it was an option because they hadn't worked out all the bugs yet. On a 73 it is just a junction block, why do you think they went to a prop valve, after 74? because of the brake bias. If there isn't a problem with the bias then why would you even suggest a adjustable prop valve? They made the later blocks a different fitting so as not to get them mixed up. The power assist booster has nothing to do with the brake pressure. It's for pedal pressure. That's why on later cars the brake pedal rod has a different ratio for applying the brakes when you have a manual system.
Check your early Stang 2+2 front disc manual brakes. They used a different junction block on it to.
...you don't absolutely need to change it if it is manual...We've been through all this before on the MMB...On '74 disc brake models Ford used the SAME prop valve as the '70-'74 drum brake models. I converted to disc on my '73 and used the stock "junction block" (which is all it is) with NO problems. The proportioning valve helps reduce rear-wheel lockup on these vehicals. You only need it IF you experience a problem with that, in which case, an adjustable prop-valve would be even better. I admit that '74 calipers were different from '75-'77 but the original '73 "junction block" seems to work fine with my '75 calipers. I assume he's going with the power setup since he got everything from the granada in which case he must swap the valve because the power brakes will be much more "touchy"...
:
: : you need to change it, power or manual. It is pressure actuated and makes the bias in the disc system work properly.
:
: :
: : just brought disc brake setup off a Granada. Do I need to change the proportional valve too? The one off the Granada is different.