Front Brake Drum Getting Hot

[USMC67300]

A few weeks ago I replaced the front brake pads on my 67 300. On the passenger side i also put a new wheel cylinder and hose on. The car stops great but the passenger side drum gets HOT. The driver side is warm but you cannot keep your hand on the passenger side. The brake is not locking up. I have jacked it up right after a 5 mile drive, the wheel turns freely , I have tried backing off the adjuster and it still gets hot. I inspected and re-packed the bearing but maybe i missed something. I didn't turn the drum when i re-did the brakes, could that be the culprit?

Thank you for your input.

 

[67Monaco]

Something is causing some friction in there. If it were me, I'd really take a closer look at the contact of the shoes to the drum. It doesn't take a lot of contact to get a drum hot. It could be that the new wheel cylinder is allowing the shoes to drag just a bit after application and then they free after a certain amount of time. Perhaps jack up the front, pump the brakes then go to the passenger side and see just how free that wheel spins. I'd also verify that the wheel cylinder is in fact a front and not a rear.

 

[USMC67300]

Thanks Monaco< i'll jack it up today and see what it does, i'll pull the drum and do a visual too

 

[bluefury361]

brake drag.....

It's always a good policy to replace wheel cylinders, hoses, linings, springs...etc. in pairs. Did you verify that the cylinder bore is the same as the old cylinder...?
Perhaps a small piece of debris got into the system during reassembly.
Is the brake surface of the drum equal to the other side....?

 

[67Monaco]

Thanks Monaco< i'll jack it up today and see what it does, i'll pull the drum and do a visual too

You might have to check it after it gets hot too. It's worth a check anyway.

 

[1978 NYB]

How old are the brake hoses?

 

[USMC67300]

The hoses were original, i took it for a cruise, jacked it up and couldn't turn the wheel. Disconnected the new flexible line and after a few seconds it spun freely. i then disconnected the hard line at the master cylinder. And flushed out the hard line from the cylinder thru the dist. block. Re-bled all of the wheels, great peddle feel. Seems like it is equal to the driver's side now.

Now if i could get the warning light to go out. If i disconnect the cable should it go out? I havent checked the E brake yet.

Bluefury - I did verify that the bore was the same as the old unit but i am kicking myself for not doing both sides. I'll pop the other side off and replace the cyl and hose too, it is only $20 for both, Cheap insurance.

 

[1978 NYB]

Replace those brakes hoses. That's the problem. The hose is collapsing inside and won't release the brake fluid when you take your foot off the brake. You can't see it from the outside. The hose will collapse and the brake will stay locked and overheat and will destroy all the parts at that wheel, bearings, seals, cylinder, warp the drum and even could start a fire. I would replace ALL brake hoses immediately. Are the hoses cracked or dry rotted on the outside? Another reason to replace the hoses.

 

[bluefury361]

Brakes....

Replace those brakes hoses. That's the problem.QUOTE]


He had said that he had replaced the hose on the wheel that was giving him the problem,.... Still a good policy to replace the other and the flex hose on the rear axle.

I suspect contaminated fluid was the culprit.

 

[bluefury361]

centering the proportioning valve...

Now if i could get the warning light to go out. If i disconnect the cable should it go out? I havent checked the E brake yet. QUOTE]

You may need to center the proportioning valve switch. It is designed to light the warning indicator on the dash if a loss of fluid on one of the two brake hydralic systems occures. When you flushed the line it may have disturbed it.

I haven't done this in a long time but I think the wire and switch on the valve must be removed, everything centered and reassembled. I'm sure the procedure is outlined in your service manual.

 

[thrashingcows]

Advice that I follow now is to flush your brake fluid every 2 years. It only takes 30 minutes or so for me to do it by myself, but you'd be surprised how nasty that fluid gets. Also will prolong the life of all your brake components.

 

[BillGrissom]

I have seen rust junk clogging brake lines. I now use silicone brake fluid (DOT 5) in all my non-ABS cars. You will hear mixed stories on it, but the U.S. military uses it.

 

[bluefury361]

I have seen rust junk clogging brake lines. I now use silicone brake fluid (DOT 5) in all my non-ABS cars. You will hear mixed stories on it, but the U.S. military uses it.

I agree with using DOT 5 fluid. Just be sure your system is clean before adding it. It does not mix well with other fluids. A big advantage is it's resistance to moisture accumulation in the system thus adding longivity to your componants.