Projects Drum Brake Dragging

I have one rear drum brake that is dragging and getting hot.

This is on a ford 8.8 rearend. The car has disks on the front and stock ford ranger 9” drums on the rear.
Temps after 20min of driving are:
Left front rotor 150°
Right front rotor 130°
Left rear drum 420°
Right rear drum 110°

I don’t think it can be the rear flex hose since that includes the T fitting to both rear wheels so if it was a bad flex hose both rear wheels would drag.

I’ve replaced both rear wheel cylinders and the hard line between the T and the left rear wheel cylinder with no improvement.

it’s not a wheel bearing, I measured the temp on the end of the axle tube and the backing plate at 150° so the heat is not coming from the wheel bearing. All the heat is in the friction area of the drum.

what’s more strange is that the car rolls easily as if the brakes are not dragging.
In neutral it will roll back down my driveway as soon as I release the brake pedal.

I’m at a loss here and wanted to take the car to a show this weekend about 3 hours away.
All suggestions are appreciated!

 

Are the drums new? could be egg shaped maybe?

Parking brake cables evenly adjusted?

 

Have you tried holding the shoes w/ 2 large screwdrivers to prevent from blowing the wheel cylinder out.Having someone apply the brakes and see if the shoes expand and retract.This would eliminate brake return springs cond, wheel cyl. cond. any bind on backing plate I would also apply the park brake to see if that's retracting.Then go from there.

 

I’ll try this tonight when I have a second set of hand/feet.

the park brake is definitely not this problem, with the car in neutral on my slightly slopping driveway it will roll as soon as I release the parking brake and stop as soon as I apply it again.

the wheel cylinders are new so that really only leaves the springs?

 

The drums are not new but the car was sitting for a year so they could have some rough spots, I’ll pull the drums tonight and have a look,
I might have a spare one I can try

 

After driving and the drum is hot, crack the bleeder on that side, and see if fluid comes out under pressure. If so you have a partially plugged brake line. Even though it's only one side, I would still suspect the rubber line going to the T. The return springs may just be weaker on the hot side.

 

Have you jacked both rear wheels off the ground and turned the wheels by hand to compare how they feel? Pulling the drums will tell you if one adjuster is tighter than the other side also. It could be an automatic adjuster that's not working properly and simply has one side adjusting up more than the other.

 

I tried this and only got a dribble of fluid, not pressure.
The flex hose is only a few years old but it’s on the list of last resorts

 

Are the leading and trailing shoes oriented properly? Is the self adjuster hardware being used and is it working properly? Is the brake pipe from the T-fitting to the LH wheel routed near the exhaust or some other heat source? Are the star wheel adjusters (LH & RH) on the proper side and do they turn freely?

You mention that the car easily rolls backwards. Keep in mind that by design self-energizing brakes don't apply as much braking force in reverse as they do when moving forward. And as @garyf already mentioned, make sure that the parking brakes release easily and completely.

Next time you have the drums off post a couple pics of both sides of the brake ***enblies.

 

the adjusters are backed off more than I would expect, on both sides the drums slide on and off with no resistance.
I normally set drum brakes with some drag but these have none and the left side is still getting hot.
It’s so loose that I’m surprised the rear brakes are doing anything but I tried a panic stop on gravel and all 4 wheels locked up.

 

the small shoe is on the front whim told is the correct orientation,
The self adjusters are so loose they are not doing anything, but all hardware is there and installed correctly.
I haven’t driven it enough for the adjusters to adjust any slack out and the drums slide off easily even after driving.

the bake lines are away from the exhaust,
Star wheels are new and moving free and installed on the correct side but screwed in so far that they are not actually adjusting.

I’ll post some pics after work

 

With your replies, I'm thinking your problem isn't brake related. Is the exhaust really close to that wheel end? If not, wheel bearing or a tire problem come to mind.

 

Look at the shoe mounting area on the backing plate. I have seen gouges there does not allow the shoe to retract.

 

I'm sure you'd hear it or it'd have clearanced itself by now but could the drum be touching the backing plate?

 

This is very common on backing plates with a lot of miles on them and new shoes will hang up on the grooves.
You can slick them off with a flap wheel or grinding wheel and then just put a finger smear of grease on them. Back when I was a high school auto shop student I was told to use a tiny bit of white lube.
I'd check the springs for condition and to make sure that you have them in place correctly. Back in my Firestone tire store front end and brake days I'd get one of those "me and my buddy changed the brake shoes on my _______ Saturday and they don't work right now, can you look at it"? cars that one of the issues was often that the springs were installed wrong or were bad.

 

^^^^ What he said. The drum should not be rubbing on the plate.

 

This is the hot side

 

This is the cold side

 

I smoothed down and lubricated the contact patches already and no improvement ☹️

 

No, the exhaust is nowhere near the brakes and it’s dual exhaust so it’s the same on both sides

 

On the dragging side, the forward retracting spring looks sketchy. Looks old and worn out and possibly isn't retracting the shoe like it should.

 

Good catch
That’s an old spring from my spare parts bin,
I swapped out the new green spring for that old one trying to fix the problem,
I might as well put the new spring back inZ

 

Are they the Chinese, brand new type ?

 

Have you check the drum dimensions?

Got a pal to operate the brakes without the drum fitted? Compare side to side.

fitted the drums with the wheel mounting face to the axle flange and run it up on stands?

I feel that’s gunna be your best way to diagnose this, static inspection isn’t getting far.

 

Chinese is the only thing available,
These are Dorman

 

When I had a similar situation it turned out to be a master cylinder problem.

 

Switch those springs from side to side

 

I just noticed how bent the backing plate is,
I wonder if that’s the issue?

 

Brakes generate enough heat to heat a entire house.White lithium grease even tho it is the go to grease to lube the brake shoe contact points on backing plates.It has a low melting point.( might be the reason for worn grooved backing plate contact points) There is better greases available,made for this purpose.Even a light film of disk brake wheel bearing grease is a better choice with a much higher melting point.

 

All those springs look old and sketchy, get a new spring kit.