Brake upgrade Problems

[56Alan]

Just got my rear cylinders stainless sleeved but........... fitted to the axle and I have the same problem, spongy low pedal. Clamp the rear flexy and I get a good firm pedal, adjust shoes so they lock on, firm pedal. Adjust shoes correctly, spongy low pedal. Using a Ford non power 15/16" dual master with Rusty Hope disc kit 2lb and 10lb residual valves and the standard 1/18" rear cylinders. I am thinking a miss match with the master and wheel cylinders? anyone have any ideas?

[ptwothree]

Might sound dumb but, I've done it.  Do you have a copper washer installed between the flex hose and rear junction?  Front calipers and hoses.  

[JerseyHarold]

Activating pins  (that fit into the wheel cylinder to activate the shoes) from some wheel cylinders have deeper slots for the brake shoe to fit into.  If you have mismatched or incorrect links the brake action will be erratic and you won't get a firm high pedal.

[56Alan]

My rear hose seals on the taper in the tee union not like the front banjo bolts. no evidence of any leaking fluid but a good point.

[56Alan]

Regarding the shoe pins, these are the shoes that came with the car and the pins are fixed to the shoe. I assume these are correct for the car?

Starting to think the MC may not be pushing enough fluid to the rear cylinders or is faulty?

[Dartgame]

My guess is piston bore. A 73 dart with disc brakes uses 15/16 bore rear wheel drum brake cylinders, and 15/16 bore master cyl.

[56Alan]

Dartgame, I think your on the right track, the Ford MC I used is for Mustang 2 and Falcons which use a 7/8" bore rear cylinder so looks like I have another modification to do!