i hate brakes

so i have a 55 dodge with twin leading shoes brakes in the front. i switched the original master cylinder to a dual master cylinder. now the piston are popping out of the wheel cylinders. the front lines are original and i'm still running the original proporationing block. the wheel cylinder are new and then i put in rebuilt kit after i popped the pistons.
if anybody has any advise for me, i would appreciate that.

thanks,
vadim

 

are the seals in the right way?

 

Do you have all the springs on? I made the mistake of leaving a spring off when taking my parking brake cable off, so the shoes moved out too far. Although I can't imagine how the pistons are popping out with the drum on.Thanks,Kurt

 

how much have the drums been cut ???? Are they beyond the limit??? Is the bore of the new master smaller causing more pressure deforming the drums to the point of wheel cylinders poping out ???

 

Did you adjust the shoes out for drag on the drums and are the bottom of the shoes sitting in the correct place ?

 

My old Plymouth had 10" brakes, my Dodge had 11"; I think my Chrysler has 12" drums. Most of the stuff inside looks the same - but I don't know if it is or not.

So the point is: are you sure you didn't get a 'mix-&-match' set of parts? Shoes, cylinders, and the little goofy rods that go between 'em.

And what the previous post said about oversize drums... that was the first thing popped into my head, but I think the linings would have to be gone from the shoes, and the drums would have to be so oversize that they'd literally be like tin foil. I took a set apart that were about .090-.120 oversize (limit .060 I think) and had paper thin linings left; hadn't popped cyl's.

Best o' luck.

-bill

 

Is the bore diamiter of the "old" master cylinder the same size as the bore of the "new" master? Maybe the new master is putting out more preasure then the old one could causing the brake fluid to be forced past the wheel cylinder rubber? Gene

 

were the drums on when the pistons popped out?

 

what about updateing the proportioning valve to a newer one to match the newer master cylinder ? Just an idea.

 

When the shoes are adjusted right, the pistons can't come out. The stroke is far shorter than the shoe to drum clearance.