M35A2 wheel locked up

I purchased by M35A2 W/W from the last owner over in Texas.
Got it 300 miles down the road and the truck started acting like it was lacking power.
Pulled over to put more diesel in as the last stop was 1/3 gasoline and 2/3 diesel.
Some trucks don't like gas and the lack power with gas in the tank so that was my first idea.

Anyway, I filled it back up with pure diesel and noticed smile coming out from under the truck.
Well it was from the right rear brake drum/hub.

I cooled it down with air and then some hot water and moved it 100 feet to an area where I
could park and leave it IF required. I am not sure at this time but I suspect a malfunctioning
brake mechanism or wheel cylinder.
I am going to make the 200 mile trek back up to the truck with one set of new bearings/races, locking washers, grease,
brake fluid, and a new wheel cylinder. Obviously will be taking a jack, jack stand,
and other tools.
What I need to verify is the bearing nut socket is an OTC1907.
I doubt that the bearings are bad but I never remove a hub without repacking the bearings
and sealing it up tight. The nut torque is always based on a freshly packing set of bearings
so this is my way of ensuring the torquing procedure is correct. Putting new bearings in with fresh grease
will be easier and cleaner than trying to clean and repack the existing stuff.

I also need to know that size wrench is used for brake adjustment and if anyone knows what size pipe thread
the brake lines are a the cylinder that would be good too.
This truck has MRAP tires and wheels on it so removing a tire is ok but if I were needing to load it up for tying up
that corner and disconnecting the rear driveshaft, etc., that would be impossible my myself.
I have changed drums, hubs, wheel cylinders, and shoes before on other M35s so I have that experience under my belt.
I will also take a pair of good used shoes with me as I anticipate that the ones on that corner are "toast".
Supposedly the last owner repacked all the bearings and installed new seals about 600 miles / 3 years ago.

Jim

jimm1009 said:

I purchased by M35A2 W/W from the last owner over in Texas.
Got it 300 miles down the road and the truck started acting like it was lacking power.
Pulled over to put more diesel in as the last stop was 1/3 gasoline and 2/3 diesel.
Some trucks don't like gas and the lack power with gas in the tank so that was my first idea.

Anyway, I filled it back up with pure diesel and noticed smile coming out from under the truck.
Well it was from the right rear brake drum/hub.

I cooled it down with air and then some hot water and moved it 100 feet to an area where I
could park and leave it IF required. I am not sure at this time but I suspect a malfunctioning
brake mechanism or wheel cylinder.
I am going to make the 200 mile trek back up to the truck with one set of new bearings/races, locking washers, grease,
brake fluid, and a new wheel cylinder. Obviously will be taking a jack, jack stand,
and other tools.
What I need to verify is the bearing nut socket is an OTC1907.
I doubt that the bearings are bad but I never remove a hub without repacking the bearings
and sealing it up tight. The nut torque is always based on a freshly packing set of bearings
so this is my way of ensuring the torquing procedure is correct. Putting new bearings in with fresh grease
will be easier and cleaner than trying to clean and repack the existing stuff.

I also need to know that size wrench is used for brake adjustment and if anyone knows what size pipe thread
the brake lines are a the cylinder that would be good too.
This truck has MRAP tires and wheels on it so removing a tire is ok but if I were needing to load it up for tying up
that corner and disconnecting the rear driveshaft, etc., that would be impossible my myself.
I have changed drums, hubs, wheel cylinders, and shoes before so I have that experience under my belt.
I will also take a pair of good used shoes with me as I anticipate that the ones on that corner are "toast".

Jim

Click to expand...

Yes thats's the right socket.
3 Inch, 8 Point, Socket

You might want to confirm you have the problem with no air pressure.

Sometimes a bad air-pak can show up like this.

Wouldn't the problem be with all brakes?
I only have one brake malfunctioning.

Jimm1009, a bad airpack would show on all drums since it's a single circuit design in a perfect world. You perhaps have a broken brake shoe spring allowing the brake shoe to stay engaged to some extent. It wouldn't take much friction running down the road to heat stuff up. I recently had a bad air leak that caused my M923 to barely hold 60 psi. I smelled brakes burning on all 4 corners of the rear after 4 1/2 miles of making it to my safe spot.

That is what I am thinking.
Am about 90 % sure that I have a broken shoe, binding shoes due to a spring issue, or a stuck wheel cylinder.

I just want to make sure since it is a 400 mile round trip to get back home.
I would rather take too much than one single, not enough, item.
Jim

Does anyone remember what size wrench is used to adjust the brakes?
I want to make sure I take it along as it is such a long trip to end up without
something vitally important.
Jim

11/16" for the upper adjusters.

I think the jam nut on the lower adjusters are 1 1/8 inch and a 1/2 inch on the stem. It's been a while though.

Put RR tandem side up on the jack stand and back that set of brakes shoes all the way off. If it is internal problem you might get it to spin just like that. Take jackstand for the left side too to get the whole rear tandem up to spin either side without pulling an axle. Take the proper fitting (inverted flare plug) with you and line wrench to disconnect the wheel cylinder. You can get to home that way. Just disconnect to the offending wheel cylinder and plug it. This is without taking it all apart as one never knows what one will find in there. Think key way cork and things and axle oil covered shoes.


If you do take it apart remember that dawn and lots of newspapers and trash bags will help a lot cleaning.
Take your IR heat gun sensor, it is your friend with all these hubs.

Yikes, that's ugly. The parts to disable a single wheel brake can be easily kept onboard in a ziplock bag. Nice idea.

I was able to check things out yesterday. The forward plunger on the wheel cylinder stuck in the partially extended position.
I drove the plunger back in, retracted the shoes in as far as possible, repacked the bearings, and reinstalled the hub.
The last owner did not know what he was doing and did not install the cork so the seal leaked and washed out all the grease and the bearings
were running in gear oil.
I am going to remove all the hubs and clean/inspect all the bearings, install new seals with corks correctly sealed into place, install all new wheel cylinders
and all new brakes hoses as the one that I removed was badly dry rotted and then I should be good to go. If I don't have my truck shipped to Louisville I will be driving it there but either way I need good and dependable brakes.
I will replace the brake shoes on that corner as the one was dragging but the drum is lightly scarred too.
My drum appears to have never been turned so I will try to find someone in the Baton Rouge area to do that.
Am going to replace all the springs in the brake shoe area too and carefully inspect everything there too.
The truck made the last 200 miles without a hitch.

Once it is found that an incomplete brake job was done last time then new owner gets to fix all that.
But then again does not have to mess with it for years after proper fixes.
https://www.youtube.com/watch?v=pZUl2EWPrTY&feature=youtu.be

Well done. Nice to read a Thorough, (Knowledgeable), competent and (SAFE) piece of maintenance work.

what size is that inverted flare plug? I have to pick up a truck 450+ miles away and am trying to bring a roadside repair kit incase something goes wrong. any suggestions on other stuff would be helpful too.