Soft pedal on '62 Valiant V8 conversion

[MOPARoldtimer]

I'm using a dual-reservoir master cylinder; Kelsey-Hayes 4-piston discs on the front; 11" drums in the rear with a proportioning valve; and the brake lines are new. I'm not sure what pushrod I'm using, and I'm pretty sure I've got it bled well, but not completely sure. The pedal goes most of the way to the floor on the first stroke; then comes up to where it should be on the second stroke. Would anybody have any suggestions about what I should check? How can I check and set the pushrod-to-master clearance? Thanks.

 

[BillGrissom]

Do you have a vacuum booster? If not, how will you set the pushrod-to-MC distance? Using shims on the MC? I understand that manual and power pushrods are different lengths. Manual ones should have a groove on the end to hold a rubber bushing.

 

[grumpuscreature]

Sounds to me like there is way too much slack in the rear brakes. Do the drums slide off or do you have to work and wiggle them to get them off? Tighten them up to work and wiggle and see what it does for your pedal....

 

[moparmat2000]

Just bcause u are using a dual chamber master cylinder is not enough, it needs to be.a.dual for front disc brakes, otherwise the bore will be too small to push enough fluid. The KH calipers are 4 piston. Thats a lot of fluid to push compared to front drum wheel cylinders.

If you are using a drum/drum dual chamber master swap it for a disc/drum one, bleed the brakes, then check, also make sure linkage rod is correct length, and rear shoes are adjusted properly.

Just my .02
Matt