I recently did a rear disc conv. new everything except master cylinder and prop valve 100% bled out and it seems my rears hardly do anything I have read posts about locking up but mine feels as if the rear barely works, can the prop valve be bypassed for the rear? or is there another fix for this Thanks Frank
CK5
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Disc brake conv.
- Thread starter 85 blazer
- Start date
Muddytazz
1 ton status
You bypass the stock prop valve by putting in a manual prop valve /forums/images/graemlins/thumb.gif
When I did my conversion I didn't have to do ANY mods to make them work differently. My brakes have never locked up, but when you lock up brakes you're not really stopping either /forums/images/graemlins/dunno.gif My buddy Don had nothing but probs, biggest thing was bleeding them, we would work for hours and go through qts of brake fluid. Turned out the calipers were on upside down. /forums/images/graemlins/doah.gif The fluid would flow into the caliper and drain right out the bleeder screw. No air bubbles or anything, just good clear fluid. ended up the resovoir never even filled up. So make sure the bleeder screws are on top of the caliper. In the end we put the left caliper on the right side and the right caliper on the left side. Stops like a champ now! Good luck, I hope it's this simple for you.
Depending on what calipers you are using (caddy in particular) you've got to make sure they are adjusted enough so they are actually gripping the rotor.
Triaged
1/2 ton status
To get full pressure from the rear unbolt the rear part (where the line for the rear brakes attach!) of the combo valve and take the spring out and put it all back together as it came out. You will then have full pressure to the rear brakes...which might be too much.
I put ona master cyl from an 85 3/4 ton pickup helped with the pedal, but now i need 1 new caliper the right side wont release, did stop better however but still not like i expected, the calipers are mounted with the bleeders in the up pos. Thanks Frank
jwduke
1/2 ton status
I used a proportioning valve from a '81 Corvette, plus I made the rod between the brake pedal & the master cylinder adjustable, these 2 things cured my problems.
