Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: 60eldo on July 01, 2025, 09:13:57 AM

Title: 1960 Drum Scorching HOT
Post by: 60eldo on July 01, 2025, 09:13:57 AM
 Was driving on highway the other day and heard some noise on the highway, so pulled over and decided to check rear drums cause I just replaced rear shoes 2 weeks ago. Right rear was scorching hot. I lifted RR tire and it turned freely. Next day I took car for a drive on highway about 4 miles and never touched the brakes. Drum was same very hot. What could cause this?
Title: Re: 1960 Drum Scorching HOT
Post by: Lexi on July 01, 2025, 09:35:16 AM
One of the shoes may be dragging. Not adjusted properly or return spring not backing shoe off, e-brake mechanism sticking. If shoes replaced without turning the drums, there could be out of round contact with the new shoe, hence the noise you heard. More likely if you experienced pulsating at the brake pedal when braking. Exhaust leak near inside of rear wheel area & heating up the wheel, another potential cause. Though the noise you reported, if related to the wheel, is likely associated with the problem you reported. Not enough information though to comment further especially on other potential causes like a failing rear wheel bearing. Seems this problem was not there prior to your brake shoe job, so would check them first. Clay/Lexi
Title: Re: 1960 Drum Scorching HOT
Post by: TJ Hopland on July 01, 2025, 10:40:39 AM
Get it jacked up again and have an assistant operate the brakes and do your spin test again to see if it ever sticks or if there is maybe a delay in that brake releasing.  While its jacked might as well take it apart for a look at things maybe you will see something.  One issue I have seen is wear in the backing plate so sometimes the shoe backing gets caught in a groove sometimes and gets stuck.
Title: Re: 1960 Drum Scorching HOT
Post by: 60eldo on July 01, 2025, 11:38:19 AM
JUst took it for a drive highway with RR brake hose crimped,,,,179 F. Took grips off hose went same drive temp 299 F on drum, left side 161F
Title: Re: 1960 Drum Scorching HOT
Post by: TJ Hopland on July 01, 2025, 11:54:58 AM
This has separate hoses for the rear?  Interesting thought the usual was a single hose with a T on the axle and then hard lines to each wheel.  Or was this one of the times/cars where they were trying  dual MC's and an X pattern?  Like left front and right rear were on one circuit then rf and Lr on the other?   
 
Anyway it seems like there is at least a delay in that brake releasing and since this apparently has separate hoses that is a likely place to have the issue, an internal hose failure acting like a check valve keeping at least some pressure in the system.  If the hoses are even slightly in question just replace em.  A way to check if that is the problem would be to have someone hit the pedal then as soon as they release you open the bleed port on the suspect wheel.  If you get a good squirt of fluid and hear the springs creaking you know there was pressure being held. 

Also I'm not sure about pinching off brake hoses and operating the brakes, that doesn't seem like it would be a good thing to do.  I have heard of pinching them off and opening the bleed port on a caliper and then pushing the piston back in so you push the nasty fluid out rather than back into the system.  Hitting full system pressure against a pinched line seems like it could damage the line in the pinched area.   
Title: Re: 1960 Drum Scorching HOT
Post by: 60eldo on July 01, 2025, 12:31:34 PM
It is separate brake hoses,one at each wheel
Title: Re: 1960 Drum Scorching HOT
Post by: TJ Hopland on July 01, 2025, 01:31:19 PM
I just did a parts lookup and based on that this is still a single MC setup and it doesn't appear that any of the other wheels are having issues so its not likely that the issue is in the MC or it would be effecting all the wheels.   That puts is out to that specific wheel and its either got to be a blockage in the line (most likely the hose) after the T on the axle not letting the fluid return thus holding some pressure on the shoes for at least some period of time or a mechanical issue inside the drum letting at shoe at least slightly rub. Being a rear wheel there is always the drag of the axle and diff stuff so you may not be able to feel a slight drag from the brakes by hand like you could if it was a front.

I would get er jacked up and try the rotation test with an assistant hitting the brakes to see if its releasing right away or if there is a delay.  If there are any signs of dragging at all I would next try having them hit the brake then releasing then you open the bleeder and see if that then frees it up.  If it does then I would suspect the hose.   If it doesn't then pull the drum and see whats going on in there.  Something has got to be causing the issue.

If its not the fluid/hose then look at the adjuster mechanism, is everything seem seated and tight?  Something occasionally getting wedged in the wrong spot?  How about the parking brake?   Assuming this is the typical drum layout you got that bar across the top is that maybe not quite right and sometimes it falls or rattles and keeps the shoes from returning? How about the little rod things that go between the wheel cylinder and the shoes?  Those oriented and seated correctly?  Or could they sometimes be falling into the wrong spot and sticking something? Like I mentioned before any wear in the backing plate where the metal part of the shoes ride?  Ridges and grooves there could be hanging up the shoes.   
Title: Re: 1960 Drum Scorching HOT
Post by: Michael Petti on July 02, 2025, 09:14:28 AM
Check your wheel cylinder. If you did not rebuild or replace them they could not be returning all the way, causing shoes to drag. I had new cylinder frozen right out of box causing drag.
Title: Re: 1960 Drum Scorching HOT
Post by: Jon S on July 02, 2025, 09:23:22 AM
Change the brake hoses!  That's the answer. And obviously re-bleed the brakes.
Title: Re: 1960 Drum Scorching HOT
Post by: James Landi on July 03, 2025, 06:33:00 AM
'Change the brake hoses!  That's the answer. And obviously re-bleed the brakes.'

Absolutely!!!  As counterintuitive as it 'seems,' old brake hoses deteriorate from the inside, and they block the free flow of brake fluid to return to neutral pressure.  The fluid is forced through the collapsed interior of the hose, but the interior of the hose WILL NOT RELEASE the pressure when you take your foot off of the brake. I've had this occur on several old Cadillacs that were decades newer than your car.


Title: Re: 1960 Drum Scorching HOT
Post by: 60eldo on July 03, 2025, 10:32:29 AM
Changed the brake hose and brake cylinder, took it for a long drive today, and all is good, drum running cool. But Ill never no if it was the hose or the cyl. Thanks guys for your help.        Mr Spock,,,take us out of orbit,  LOL
Title: Re: 1960 Drum Scorching HOT
Post by: Jeff Rosansky CLC #28373 on July 03, 2025, 10:51:16 AM
Quote from: 60eldo on July 03, 2025, 10:32:29 AMChanged the brake hose and brake cylinder, took it for a long drive today, and all is good, drum running cool. But Ill never no if it was the hose or the cyl. Thanks guys for your help.        Mr Spock,,,take us out of orbit,  LOL
That's the problem with doing 2 things at once. But I get it, you dont want to bleed it twice. You can pull the rubber boot off the cylinder to see if it is corroded in there, but my money is on the hose.
Glad you got it fixed. Now take her out and drive her.
Title: Re: 1960 Drum Scorching HOT
Post by: James Landi on July 04, 2025, 06:43:49 AM
Jon, if you determine that the other three brake hoses are from the same period (of time) as the one you just replaced, then change the other three.  As mentioned above, brake hoses deteriorate on the inside, and  they collapse on the inside causing the wheel cylinders to apply continuous pressure on  the brake shoes .  My most recent experience occurred on a garage kept 58 k miles 1988 Cadillac Allante. Service life of decades old parts is a serious consideration.
Title: Re: 1960 Drum Scorching HOT
Post by: TJ Hopland on July 05, 2025, 10:17:14 AM
Just curious how old was this hose?   And what do others think of the practice of pinching off a hose then applying full pedal pressure on it?  That just seems bad and like it could cause damage to me but I don't have any experience that proves that. 
Title: Re: 1960 Drum Scorching HOT
Post by: The Tassie Devil(le) on July 05, 2025, 08:05:29 PM
Have you had a good look at the old hose?   I would cut it in half lengthwise for the whole length and see where the blockage was.

Bruce. >:D
Title: Re: 1960 Drum Scorching HOT
Post by: Michael Petti on July 06, 2025, 06:02:48 PM
I suggest opening the old wheel cylinders to see how much crud was in there to impede the movement of the pistons.