Need a Drum Brake Expert

[mopar Joe 65]

My right front brake grabs periodically when not even braking, I pulled off the front wheel and the front shoe would not retract all the way ? I replaced the wheel cylinder and it’s better but still does it ? My spring looks ok but maybe it’s not strong enough ? Any advice is appreciated.

 

[Davea Lux]

My right front brake grabs periodically when not even braking, I pulled off the front wheel and the front shoe would not retract all the way ? I replaced the wheel cylinder and it’s better but still does it ? My spring looks ok but maybe it’s not strong enough ? Any advice is appreciated.

Start by replacing both front brake hoses. The inner lining sometimes separates and blocks the brake fluid from returning. This will cause the wheel cylinder to stick in the deployed position. Some other causes could be grooves worn in the brake backing plate, this can cause the brake shoe to hang up if the wear groove is deep enough. If you have replaced the master cylinder, be sure that the travel rod is properly adjusted. A travel rod that is set too long prevents the piston in the master cylinder from retracting properly, this will cause a blockage that prevents fluid from returning. The test for this condition is to crack the bleeder screw on the affected wheel cylinder, if it retracts, the travel rod is probably set too ling. Check the front wheel bearing adjustment, if it is set too loose the brake drum will wobble and also cause braking issues. Finally, where the brake shoes contact the backing plates should have a small amount of white grease applied to the mount tabs. The tabs are small bumps that protrude from the backing plate and contact the side of the shoes. A little grease keeps the shoes from hanging up, especially if the tabs are rusted. If you have not already done so, down load the factory FSM at www.mymopar.com it is free and covers various adjustments to the braking system.

Dave

 

[mopar Joe 65]

Thanks Dave, I will try your advice and let you know what I find . I think my hoses are ok most everything is new ?

 

[Ross Wooldridge]

Old hoses, even if they look OK and don't warrant replacement from a visual inspection can be bad inside...

 

[watchfatha]

FWIW Brake hoses can look great on the outside but be collapsed on the inside, which causes them to act as a one way valve, not releasing pressure and applying the brakes long after you have lifted your foot off the pedal. Been there, done that.

 

[1970cat]

are the bumps on the backing plates that the shoes slide on smooth and lubed?

 

[watchfatha]

cleaned, lubed VERY lightly. Problem more likely to be hose than platform.

 

[halifaxhops]

@mobileparts

 

[73Coupe]

Thanks Dave, I will try your advice and let you know what I find . I think my hoses are ok most everything is new ?View attachment 497907

Is that bottom spring pulling the shoes together tight enough?

 

[Pax2001]

Is that bottom spring pulling the shoes together tight enough?

I'm not seeing a bottom spring between the shoes...

 

[Clover]

Sounds more mechanical than hydraulic to me.

My right front brake grabs periodically when not even braking

My bet’s on the backing plate. Time for a little weld and grind session.

 

[C-HP Polara]

I'm not used to seeing back-up auto adjusters on the front. My 11x3 inch fronts only have a spring across the adjuster firmly holding the shoes together and then manually adjust

 

[C-HP Polara]

Also, kinda remember different color top springs (one being green), ?different tension to pull in the piston?

 

[Ross Wooldridge]

I'm not used to seeing back-up auto adjusters on the front. My 11x3 inch fronts only have a spring across the adjuster firmly holding the shoes together and then manually adjust

My 3" brakes (66, Canadian car) had adjusters all 4 wheels. Odd, eh?

 

[LEWISEMATKINJR]

I'm not used to seeing back-up auto adjusters on the front. My 11x3 inch fronts only have a spring across the adjuster firmly holding the shoes together and then manually adjust

Self-adjusting brakes came out between 1962-1964. Every vehicle I personally have owned or worked on that was from that vintage and newer, came equipped with self-adjusting brakes. And I agree with the previous comments about the rubber brake hoses. If they are original to the car, replace them.

 

[Ross Wooldridge]

True enough, but typically 3-inch brakes (up until 1968 or so) did not use automatic adjusters - or so I've been told... but the odd time one will find some 3" brake systems were equipped... like mine.

What I can't find is an option code on a fender tag for adjusters on 3 inch brake systems...

 

[John Kirby]

A total guess here. Are the shoes on correctly? one has more surface area than the other. They could be swapped. I don't remember if the larger shoe goes in front or not. I swapped to disk brakes years ago so my memory is rusty.

 

[Detroit_Lives]

This is just a guess but something doesn't look right with the lower spring. Isn't it supposed to hook on the peg that sticks out from the shoe just above the adjuster tip on the RHS..?