[Nenuko12]

Hi everyone. I noticed when braking was finished the rear shoes (apparently both driver and passenger sides) on my 1970 coupé don’t retract and continue to engage the drum around 30s before finally retracting. I took drums off, all springs and wheel cylinders got replaced (did not replace any rear shoes since both are still in good shape) and brake system was bled. However rear brake’s issue still on.

Any idea what would be going on? Brake proportioning valve?
Thx

 

[Maxum96]

Around 30's? How do you know the shoes are still touching the drums?

 

[Nenuko12]

Around 30's? How do you know the shoes are still touching the drums?

I jacked up the car and after braking drums are locked up before spining again later (around 30s after). No issue with the original front disk brakes.

 

[Maxum96]

What do you mean when you say around 30's? Pull a brake drum off and take several pictures form different angles of your brake hardware so we can see if something is assembled incorrectly.

 

[Nenuko12]

What do you mean when you say around 30's? Pull a brake drum off and take several pictures form different angles of your brake hardware so we can see if something is assembled incorrectly.

Thank Maxum I'll do it. About what I m saying when I say around 30s is that after realeasing the brake pedal have to wait around 30 seconds to get the rear drum 100% unlocked.

 

[awhtx]

Is the rubber brake hose between the body and the axle 50 years old?

 

[CJM68GT390]

My guess: bad flexible line from the body to the axle housing. They can deteriorate internally (but look fine externally) and block the flow of fluid. How old is your line?

Edit: Damn, @awhtx beat me by mere seconds.

 

[Woodchuck]

Internally split rear flex hose, sticking master cylinder piston or junk plugging internal port, heavily grooved backing plate wear pads, stuck parking brake cables/levers, contamination of brake linings....