brake issues

[hotrodredneck]

Let me start this by saying that the shoes and wheel cyl's are all new, drums are not out of round either.



So when I got the 64, I noticed the driver side brake grabbed real hard. I pulled the drums, saw all was new inside and the drums were not out of round, re-adjusted them, and then the passenger side starts....I went back and forth for hours..then gave up


now when I drive it, one day one side will grab, then the next the other

 

[66HertzClone]

Check the condition of the pads on the backing plates. A groove can wear in them that will cause the shoes to hang up. Sometimes a little lube will help, other times the groove will need to be welded up and ground flat again.

 

[hotrodredneck]

never heard of that....I'll have to check it out this week sometime...car is parked right now...thanks


anything else that could cause it?

 

[krash kendall]

Loosen them up, put the drums back on, then reach through the access slot in the backing plate with a flathead screwdriver and adjust them up to equal friction. See how long that lasts.

It is quite typical for one to self-adjust before the other if you only adjust them with the drums off.

 

[hotrodredneck]

I adjusted them with the drums on, the only way I knew how too. Never tried to adjust brakes with the drums off before. Guess I didnt word it well in my first post...sorry, thanks though

 

[65 fastback]

Don't the drum brakes automatically adjust when stopping in reverse? I remember going to empty parking lots and repeatedly reversing and stopping to adjust the 4 wheel drums on my '67.

Tim

 

[mustangdave]

Yea they do but most people don't get them assembled well enough to work or the star adjustor has worn teeth. Even when perfect, it wasn't a very good design.
Any grease at all on the shoes will cause grabbing also. An improperly installed spring could be binding. After checking the pad for a groove, install a little grease on it to help the shoes slide. Remember, you don't want much or it could heat up and get on the pads.

 

[2nd Mustang]

I just went though the same problem with my 67 coupe. It was locking up on the right rear drum brake with just moderate brake pressure applied to the pedal. The shoes looked good, but replaced them anyway, cleaned out the drums really good, applied new grease to the shoe contact points on the backing plate, adjusted the brakes, and shazaam, no more locking up of rear brakes.

 

[hotrodredneck]

I'll pull the drums off again and check those points on the back of the dust plates.


Thanks for the help y'all

 

[hotrodredneck]

ok, well it's been a while, and I jsut got the car temp registered yesterday. Pulled the drums off, and sure enough, no grease...backing plates had no grooves though.

So, when I went to bleed them, I went to the pass rear first...opened the bleeeder, and it was a PITA to get fluid to come out....same on the drivers side rear...Brakes are engaging though.

If I took the the proportioning block out and blew air thru it, to make sure no gunk is in there, will it be ok? I mean, are there any valves, or ball bearings that would get screwed up?


another question. I have a spare Master cyl....if I take the lid off that one and set it up to push air in, could that help clean out the brake lines?

 

[hotrodredneck]

anyone?

 

[mustangdave]

Did your brake light come on after reinstalling the proportioning valve?
I would attach a hose to the bleeder valves one at a time and let it gravity drip.Check it every few hours to top off the mc. Were the wheel cylinders new on the back too? If they are corroded they could be sticking or clogging the rear fluid.

 

[2nd Mustang]

These brakes are pretty much very basic. When I first bought my 67 coupe, I rebuilt the rear brake cylinders with new rubbers, etc. I honed out the inside and cleaned them out. I also disconnected the lines at the distribution block and at each wheel and blew air through them just to make sure there wasn't any crud in there. I still have issues with the distribution block causing that brake light on the dash, but it doesn't seem to alter the braking any.

 

[mr.terry66]

don't forget to check the condition of the flexible lines that connect to the wheel cylinders. they break down over time and can have problems with clogging as the hose deteriorates

 

[hotrodredneck]

Did your brake light come on after reinstalling the proportioning valve?
I would attach a hose to the bleeder valves one at a time and let it gravity drip.Check it every few hours to top off the mc. Were the wheel cylinders new on the back too? If they are corroded they could be sticking or clogging the rear fluid.

wheel cyls are new all the way the around...same with shoes and springs

don't forget to check the condition of the flexible lines that connect to the wheel cylinders. they break down over time and can have problems with clogging as the hose deteriorates

will double check the lines today

 

[hotrodredneck]

found it....
well went to the craft shop today and decided to do a brake fluid flush....glad I did, the stuff in the MS looked like crap!!!....plus I found a safty seal from an old bottle of brake fluid in there....go figure....