Brake woes

[ChryslerKid]

Leaving the parking lot(slick asphalt) from work today in my cordoba. Driving maybe 10 mph and when i hit the brakes the driver rear tire locks up leaving a visible skid mark. Limp her home with a hard pedal and pull off the opposite side drum. When the pedal is depressed one side of the wheel cylinder slightly moves the other not at all. The cylinder also seems to be leaking so i replace it with a high quality chinese one. No difference at all. It doesnt feel like a failing master cylinder seal where you get no pedal then all of it at once, it just feels like all the braking power is going to the rear driver tire. Would the next step be the proportioning valve?

 

[1STMP]

Did you bleed the system after changing
the wheel cylinder?
Sometimes, on an older system, the valve can
stick. Try tapping on it lightly prior to the
bleeding procedure.

 

[ChryslerKid]

I only bled the side where i opened the line. Ill try tapping on it and bleeding out the whole system when i get home. Looks like ill be taking the newport today.

 

[slimt]

How are your outer axle seals? If they leak in the drum. It could cause the shoes to stick when brakes applied or your shoes are glazed.

 

[ChryslerKid]

Axle seals arent leaking. They drums are pretty glazed over but i drive the thing 25-30 miles to work every day so ive got a good feel for her. Something drastically changed in the 10 hours i parked it.

 

[f569]

Sacramento Ca?
I think you've been vandalized.

 

[khryslerkid]

Bleed both rears. Shouldn't need to bleed the fronts unless you let the mastercylinder run out of fluid. Right rear first then left rear.

 

[Ron H]

Couple a quick thoughts: Assume you found even flow of fluid on each side when you bled them? Check the brake shoe wear on each side…one side could be worn much more than the other. Make sure the self-adjusters are working properly; (I had one where the adjuster worked its way off the star (I couldn’t align the adjuster lever so replaced the adjuster hardware). What is the condition of the rear rubber line? Have someone press the brake pedal and see if it is bulging; a sign of a skanked hose. Check the T-block on top of the axle housing as they can get gummed up…

 

[ChryslerKid]

Thank you for the input guys. I am going to go through everything this weekend when i have a bit more daylight. Messing with 45 year old hydraulic fittings is never fun luckily theres no rust. Ive been driving exclusively carbureted chryslers as my daily since i could drive, but some weeks are better than others. In the past week ive had a radiator bust a leak, a fuel pump fail spraying gas out the weephole all over the motor and now this. Still beats driving a honda i suppose.

 

[Geetex]

Just a suggestion, if you're going to do it this weekend do yourself a favor and put some penetrating oil on all the fittings today, with a reapplication tomorrow and Saturday morning, this will give the penetrating oil plenty of time to work.

 

[MoparLeo]

We have no history of your brake system so here are a few things that happen with age. Brake fluid absorbs water and needs to be flushed/replaced every 2-3 years. The moisture settles at the low points in the brake system meaning the calipers and wheel cylinders. This moisture and muck will cause wheel cylinder pistons and caliper pistons to stick. Brake lines/hoses corrode from the inside out causing blockages in the lines. Lines should be replaced periodically.
If your hydraulic components are original, they are way past their safe life span. 40+ years is a long time past replacement time for any hydraulic, rubber parts.
All fluids should be replaced every 2-3 years regardless of whether you drive the car or not. Time is the enemy of coolant, brake fluid, trans fluid, gasoline, oil..
Tires replaced after 5 years regardless of miles. These things are all chemical compounds and have a limited life span measured in time/mileage.
Once a brake shoe absorbs oil or brake fluid it should be replaced. And even if only one side is contaminated, your brakes work in pairs. Replace both sides and scuff the drums at a minimum.

 

[ChryslerKid]

So i finally got to look at this thing in the daytime. That wheel cylinder seemed to be my issue. Trying to work on this after work at night is not the way to go. What looked like dust in the dark was actually dust covered brake fluid. MoparLeo hit it on the head. When i put that drum back on and drove it again that shoe just crumbled. So i cleaned the hell out of everything replaced drums and shoes and bled out the old fluid. Everything is working fine now. My next step is to replace at least all three soft hoses. Thank you guys for all of your help.

 

[1STMP]

Thanks for the update. Glad you got 'er worked
out !