72 Drum Brake Question

[Seraph]

Hey guys,
I have a 72 c-10 that i did a 6.5 diesel swap. The motor is running and everything is working great except the driver side rear drum. When I press on the brake pedal the shoes seem to unseat and will not release, so they sit there and drag on the hub. Does anyone have a clue why this is happening? I have inspected everything and it seems to be in good order. Also this has a hydro boost system on it. Thanks everyone!

[68gmsee]

Originally Posted by Seraph

Hey guys,
I have a 72 c-10 that i did a 6.5 diesel swap. The motor is running and everything is working great except the driver side rear drum. When I press on the brake pedal the shoes seem to unseat and will not release, so they sit there and drag on the hub. Does anyone have a clue why this is happening? I have inspected everything and it seems to be in good order. Also this has a hydro boost system on it. Thanks everyone!

Assumint that by "unseat" you mean that the shoes expand and than don't retract properly. First thing is to check all the mechanical springs and/or anything that may cause it to bind then replace the rear rubber brake hose. Should be on the passenger side axle shaft.

Happened to me about 15 yrs ago. The hose swells internally allowing fluid under pressure to expand the brake shoes but the spring tension is not enough to allow it to retract because of the restricted flow on the rubber hose.