How to reset brake shoes?

[steve2724]

I screwed up. I was bleeding my rear drum brakes on my 70 Dart. I took off the drum so I could get at bleeder and I pumped the brakes without drums on. Now I can't get the drum back on...How do I get the shoes to reset so I can get the drum back on?
Thanks

 

[Syleng1]

Crack the bleeder and smack the shoes back together. You did not harm anything- it will get a bit messy but worst case the pistons in the wheel cylinders popped out of the bore.

 

[Tooljunkie]

I think you pushed a wheel cylinder apart. It may require a new cylinder. Cant just pound it back together.

 

[Syleng1]

I think you pushed a wheel cylinder apart. It may require a new cylinder. Cant just pound it back together.

Have you ever had this happen? You don’t need a new cylinder unless the old one is junk. Sometimes the shoes over extend and the wheel cylinder is fine- pistons in bore- most times however the rubber piston cup under the seal pops out of the bore and you simply take the shoes apart, reinsert the parts and then reassemble the shoes. Normal stuff to me. Easy peazy-

 

[YY1]

Once I get everything back together, I like to bang the shoes back and forth with the heels of my hands to help things settle in and center.

Agree, look closely at the pistons and those cups.

You should be able to remove the rubber cups without exposing the system to air, unless the pistons are already past the end of the bore.

The MC likely has a retention valve to keep residual pressure on the rear. because of this, you likely can't just remove the MC cap and force the pistons back to where they need to be. Using the bleeder will probably be necessary, unless you remove one or both pistons and then re-bleed that corner.

 

[YY1]

I've seen those seal cups inside the bore, in back of the pistons get cocked from over extension as well.

That can cause you not to be able to get the pistons back in far enough.

Probably better to disassemble everything and put it back together and then re-bleed unless you can see an obvious problem on one side and feel safe that the other side is OK.

 

[cudamark]

The pistons in the wheel cylinder probably came out of the bore slightly and got cocked to one side. Otherwise the return springs should have brought the shoes back to their proper position. If you have no leaks, just push the pistons and seals back into the cylinder bore, make sure the dust boots are still where they should be, center the shoes, and slide the drums back on. If the cylinders are used and leaking fluid, I'd hone them and install a overhaul new kit.