So on my 68 Newport I have front ssbc disk brakes and have my factory drums. I have a pro portioning valve for the rears and a disk brake master cylinder.

The brakes seem to be good going from 40 mph and trying to stop decently hard but going slow they seem to take forever to stop.

If I hold the brakes and hit the gas they will or stay locked in front or back. The car just begins to roll.

If I hammer the brakes hard at 40 or so they will not lock up at all. Just slows the car quick.....

I have made sure they are bled, checked the check valve and taken a look at the pads and rotors. All seems ok....... HELP!

Thanks guys.

 

MANUAL OR POWER DISC?

 

Power.

 

Sounds like the wrong master cylinder too me?

 

Sorry probably should have included that they worked good for the first couple years but this year on the road not so much.....

 

Flush brake fluid completely, all new!

 

bad master cylinder

 

I'll try this over the next few days.

If that doesn't change anything I'll look into a new master cylinder like no parted suggested.

Thanks guys.