Fixing Flat on M35A3

[glcaines]

I've been having to add air to the left front tire on my M35A3 for about a year now and finally got tired of it. This was the last tire mounted on the truck that leaked, sans the spare. I've fixed the other 5 tires previously. All of them were leaking at the valve stem grommet. None leaked from the O-ring. I used my tractor with forks to aid in the breakdown. I don't know how anyone does this without the use of forks. With the right equipment it's a fairly easy job. Once broken down, I sand any rust and paint the wheels with high gloss Rustoleum paint on the inside and flat black on the outside. I don't use any sealant. I torque the valve stem down to 45-60 Lb-Ft. Never had a leak yet on any of the wheels.

 

[gimpyrobb]

I use the hydraulic bead breaker. Its not fun.

 

[HDN]

Question about torquing the grommet: I'm using a clicky-style torque wrench to do it. I torqued it to 60 ft-lbs, then double-checked it, which resulted in tightening it further, probably because of grommet squish. Should I just torque it once, or do it until I get 60 ft-lbs without further tightening?

 

[glcaines]

Question about torquing the grommet: I'm using a clicky-style torque wrench to do it. I torqued it to 60 ft-lbs, then double-checked it, which resulted in tightening it further, probably because of grommet squish. Should I just torque it once, or do it until I get 60 ft-lbs without further tightening?

I torque mine to between 45 and 60 ft-lbs one time. I don't repeat. I've never had one leak after doing it only once. O-rings get blamed for leaks all the time when the real culprit is almost always valve stem grommets.

 

[gringeltaube]

.... the real culprit is almost always valve stem grommets.

Yeah, over the time rubber may harden and eventually even develop cracks. Also the fact that rust tends to build up due to trapped moisture there, just where the grommet has to seal.
Because of that I have long installed all my valves with no grommet and/or O-ring, at all. PU-sealant alone (Sikaflex 221 or there-like) does the trick. Just apply plenty of it, then assemble and wipe-off whatever excess squeezed out. Guaranteed no leakage & no rust either - after more than two decades, now!

And before someone asks: yes, parts installed that way can always be unscrewed, cleaned (with a wire brush) and then reused - if someone wanted to sandblast and paint their wheels, for example.

 

[charlesmann]

Question about torquing the grommet: I'm using a clicky-style torque wrench to do it. I torqued it to 60 ft-lbs, then double-checked it, which resulted in tightening it further, probably because of grommet squish. Should I just torque it once, or do it until I get 60 ft-lbs without further tightening?

General maint standard practices in my field of work state to tighten till the click and stop.

There is 1 installation procedure for my field that requires multiple clicks at 275’ lbs, to achieve the required thread protrusion.

 

[charlesmann]

As for breaking bead, i use 2 tanker bars (5’ single chisel point pry bar), a 36” standard pry bar and an ample amount of soapy water or a penetrant oil.
I had 2 wheel assy, that even snatch blocked on the 20k front winch, 1tn dually chained to my tractor and both truck and tractor chocked, and still couldnt break the bead.

 

[HDN]

As for breaking bead, i use 2 tanker bars (5’ single chisel point pry bar), a 36” standard pry bar and an ample amount of soapy water or a penetrant oil.
I had 2 wheel assy, that even snatch blocked on the 20k front winch, 1tn dually chained to my tractor and both truck and tractor chocked, and still couldnt break the bead.

I guess I'm just lucky so far. I broke the bead on the bead lock using just a pair of 36" pry bars. I then flipped the wheel upside down on a couple cubes of wood and worked the rest of the tire off the rim the same way, using gravity to my advantage

 

[charlesmann]

I guess I'm just lucky so far. I broke the bead on the bead lock using just a pair of 36" pry bars. I then flipped the wheel upside down on a couple cubes of wood and worked the rest of the tire off the rim the same way, using gravity to my advantage

I was messing with 14R20s, that who knows how long they were on the rims for before i began breaking beads. I used my tractor at first, but then after putting a fork through the sidewall of 1, i decided to find an alt. method and just did grunt work. now that i have fresh 395s recently mounted, with a petrolatum jelly around the o-rings and the wheel halves, I'm hoping in the next 3-5 yrs, if/when i have to change the tires, the beads break much easier