Front Drum brake befuddlement (1 Viewer)

[JKIII FJ40]

Working on making my 12/73 road worthy and ran in to a snag. Both front drums drag for about a quarter of a revolution. I attempted to back off the brakes, checked to see if the shoes were properly seated (discovered one of the springs were on backwards, swapped drums from the back I know were running true, I even pulled the wheel end to check the nut torque and bearings for play and proper alignment. Both wheels drag no matter what I do to the shoes. They run true with no issues up until I put the wheels on and tighten up the nuts.

What am I missing?

 

[CruisinGA]

I know this is not what you are looking for but seriously just drop the drums. I also tried replacing all the parts and keeping them in adjustment and the best fix was ditching them for disk. It only got better when I ditched the rear drums too years later

 

[JKIII FJ40]

That's the plan eventually, just didn't know if the issue could be fixed now until I can get the parts I need to convert the front to discs.
Thanks again

 

[CruisinGA]

Are you putting a couple lug nuts on to hold drum on tight when you adjust?

 

[JKIII FJ40]

Yes, spins freely up until the lug nuts are snug. Same with just the drum and with the wheel on too.

 

[JKIII FJ40]

I need to see if the back plates are some how hitting. I may try to pull the shoes and test it that way.

 

[Shark56]

After you do your adjustments are you pushing the brake pedal several times to set the shoes in the drum? Then rechecking how tight they are?

 

[JKIII FJ40]

Yes, didn't change the drag at all. Initially thought the shoes may have not been centered..Going to tear in to it this weekend.

 

[skidplate]

Fully tighten the lug nuts before adjusting the brakes. I went through this, a little harder to adjust because of the wheel on , but it can be done......with patience.

 

[CruisinGA]

You should be adjusting the brakes with at least lug nuts on holding the drums tight. I never adjusted with wheels on but might try that too if adjusting with just lug nuts snug doesn’t do it

 

[Seamus]

Fully tighten the lug nuts before adjusting the brakes. I went through this, a little harder to adjust because of the wheel on , but it can be done......with patience.

The special tool from SOR is well worth the $16 it costs.

 

[thebigredrocker]

Are your ramps oriented correctly?
FJ40Jim posted some pictures below.

The ramp on drum brake adjuster pistons oriented correctly:
View attachment 1700162

For comparison, here's the ramp oriented wrong:
View attachment 1700163

Slightly better view of piston without shoe in the way, showing high side and low side of ramp.
View attachment 1700166
View attachment 1700167

The ramps are oriented with the high side out, so the return spring tends to pull the shoe away from the drum. There should not be a big gap visible at the outside of the shoe/adjuster slot.

Go fix this at all 8 adjusters, then re-adjust brakes.
Don't introduce another variable by adding turning all 4 drums to the equation.

 

[thebigredrocker]

some orientation pictures

Can someone double check my brake shoe install

Just trying to see if my 71 FJ40 engine will run before I spend money on new brake stuff. So I'm just trying to use the brake components she came with. 1. Am I ok with the rearward springs on the outside of the shoes? The PO had all springs behind the shoes. 2. Does it matter if the side of...

forum.ih8mud.com

 

[JKIII FJ40]

Are your ramps oriented correctly?
FJ40Jim posted some pictures below.

Worth a shot, never noticed a ramp height difference. Both shoes are seated square in the groove and brakes are backed off.
Geez, now the more I look at the pics and other thread I need recheck my rears too. Thanks again, always great feedback and I learn something every day!!!!

 

[JKIII FJ40]

The special tool from SOR is well worth the $16 it costs.

View attachment 2561042

I have one, and you are correct. Makes life a lot easier to adjust the brakes....

 

[JKIII FJ40]

so, found the cause of the brake drag. One ramp misaligned and two cylinders froze causing the brakes to drag after seating the shoes.

thanks again for all of the assistance!

Cheers

 

[thebigredrocker]

If your cylinders are Japanese they might be worth rebuilding.
Cruiser Outfitter sells rebuild kits.
link—> Cruiser Outfitters - http://www.cruiseroutfitters.com/lock_cylinder_rebuild.html

 

[JKIII FJ40]

thanks, I will look in to it. I eventually want to convert to disc brakes on the front axle. For now I am just getting it running to tool around the neighborhood. Anyone out there still running front drum brakes? Curious if adjusted properly are they safe to use? I don't hot rod and drove truck for many years so I instinctively maintain stopping distance.

 

[thebigredrocker]

As you probably know, lots of people on mud are disk brake fans.

Example of a Drum brake guy—> Mark's Off Road is a good source of old school parts and knowledge. I've seen Mark mention he is happy with drums on all his rigs. Pretty sure he drives them daily. Except for his concourse 45swb

Properly working troopie drum brakes are amazing. My HJ would toss me like a rag doll at the windshield if I wasn’t careful.

All OE parts.

 

[JKIII FJ40]

many thanks, total respect to Mark and his view. Many of these rigs around the world still use drums. Your right about the FMS, uber simple to follow and maintain. Drums and shoes are good, just two bad brake cylinders, I might just take them off and soak them to see if I can free up the piston. A little emery cloth they will polish up nice. The boots are sill in great shape.