1964 front disc conv now only light pedal pressure

[vbudwick]

I see my shop guy already posted something on here but let’s see if we can get this figured out.
bought conversion kit on eBay. Came with booster, 1”dual master, brass proportioning valve, calipers, rotors, bearings etc.
I added a residual valve to rear drum line. have run new lines throughout. Bench bled master, power bled the lines. New wheel cylinders in rear.
now we can’t seem to get any more than a soft pedal. Tried to adjust pedal assembly but can’t seem to be able to push master pin enough. Booster vacuum was 11, is that enough? Bore size of master? Booster bad? Kit seemed to be all there, cant tell you a name brand, like I said eBay. Tried different master already, and yes bench bled It too.
suggestions on increasing brake pedal pressure and stop ability. At a loss here

 

[vbudwick]

Pics

 

[74 Harley]

Have you checked the adjustment on the rear brakes?

 

[vbudwick]

Have you checked the adjustment on the rear brakes?

adjusted until I get a rotation and wheel stops on its own. New cylinders as well

 

[Ward 57]

adjusted until I get a rotation and wheel stops on its own. New cylinders as well

Still air in the system or mis-plumbed.

 

[inspector]

I see my shop guy already posted something on here but let’s see if we can get this figured out.
bought conversion kit on eBay. Came with booster, 1”dual master, brass proportioning valve, calipers, rotors, bearings etc.
I added a residual valve to rear drum line. have run new lines throughout. Bench bled master, power bled the lines. New wheel cylinders in rear.
now we can’t seem to get any more than a soft pedal. Tried to adjust pedal assembly but can’t seem to be able to push master pin enough. Booster vacuum was 11, is that enough? Bore size of master? Booster bad? Kit seemed to be all there, cant tell you a name brand, like I said eBay. Tried different master already, and yes bench bled It too.
suggestions on increasing brake pedal pressure and stop ability. At a loss here

f you pump the brakes, can you build up any pressure?

 

[4VE]

The Master cyl stroke has to do with the geometry of the leverage of pedal force developed relative to the triangle of the pivot and clevis. Look up the Wilwood system and you may experience remorse for having purchased your ebay system. I am replacing my master and prop. valve with a Wilwood sys. It is in the trunk in boxes right now. I don't need to because my pedal is rock solid and all four wheels are in synch but the Wilwood system is way more charming. If you want the product number for spec. Drop me a line at gsklema at gmail.

 

[vbudwick]

f you pump the brakes, can you build up any pressure?

No.. we finally got some pressure, enough to slow the vehicle to a stop. Nothing I want to drive on, can't lock up brakes

 

[Ward 57]

No.. we finally got some pressure, enough to slow the vehicle to a stop. Nothing I want to drive on, can't lock up brakes

I may be a nay Sayer, But all these upgrades open a can of worms. My '57 is totally stock and just compensate for the engineering at the time. Stock was the best at the time. Want to put hydraulic brakes on a model A? go for it but don't expect issues on re-engineering the original set up.

 

[4VE]

Well if you are getting some pressure to the pads, take it on some loose gravel or wet grass and see if you can lock any one of the 4 up? It is possible that you have a bad casting. The casting could have an obstruction that can't be seen by the eye. Or, there may have been some obstruction in a line. Did you blow out the lines before installing them? If you pressure bled and vacuum bled out the air, there is an obstruction. Do the cheep stuff first. Replace the proportioning valve or the lines from the master to the block. My setup works like a charm. No booster needed. I set up the front/rear proportions based upon the lockup on gravel and it is sweet.