tire removal and air leak on M939 A2 series

[charlesmann]

2 fold query.
first off. How the heck do you get the dang tire/wheel off the axle? i got the front tires off no problem, but getting the rears over the axle/hub flange seems to be a booger. any easy ways? couple pipes over the studs then slide it off on the pipes? if there is no easy way, there will be 2 A2 wreckers up for sale very soon.

iv got a leak down in my sec air system. can't seem to find it. i know when i disengage the t-case pto, i do hear air bleeding off in the intake.
i did the air brake leak test/check according to the DOT requirements, and it will pass inspection, but id like to know if the sec tank bleeds off into the eng intake.

 

[simp5782]

2 fold query.
first off. How the heck do you get the dang tire/wheel off the axle? i got the front tires off no problem, but getting the rears over the axle/hub flange seems to be a booger. any easy ways? couple pipes over the studs then slide it off on the pipes? if there is no easy way, there will be 2 A2 wreckers up for sale very soon.

iv got a leak down in my sec air system. can't seem to find it. i know when i disengage the t-case pto, i do hear air bleeding off in the intake.
i did the air brake leak test/check according to the DOT requirements, and it will pass inspection, but id like to know if the sec tank bleeds off into the eng intake.

Let the Jack down till its even with the wheel face and walk it out. Adjust the Jack as needed. Wait till you get to put em on if you think thats a pain

Use the p2p program in the technical manual section. It gives you the routing of all the air lines.

You can isolate on the vents behind the air filter. 4 of them converge there. Remove each line one at a time and see which one has air and report back which way it goes on the fram
Probably a Q2 valve or treadle ( brake pedal) valve are the obvious ones.

For the brake pedal you can remove the lowest air line going into it in the engine pay.with a 7/8 wrench. Thats the vent for the treadle valve

All vent lines are white in color on tracking it down

 

[charlesmann]

Let the Jack down till its even with the wheel face and walk it out. Adjust the Jack as needed. Wait till you get to put em on if you think thats a pain

I'm robbing the parts truck for the stuff to get me dot legal, and the truck is in a field, that is softer than i thought. i put a 2' long section of r/r tie for shoring, then blocked the front up and let down on the crane cable and lowered it onto the blocks. the shoring under the front is almost level with the ground now. i used the crane to lift the rear as much as i could, but mostly took weight off the axels it seems. i repeated with the rear as i did with the front, and the 3 rear tires I'm taking off had sunk about 4"-6" in the ground.
even my stabilizer pads on the operational wrecker/crane, sunk over the 3 hrs i was holding weight of the canned crane.
im gonna take weight off the rear again tomorrow, but I'm gonna get 3 12" sections of whatever will fit over the studs, but will go through the stud holes in the rim. plus put the bucket on my tractor and dig out below the tires and try to slide the assy, over the pipes and into the bucket.

these things are NOT 1 man friendly. i might be better off getting an M88 track recovery track. only down side, its not as useful as the crane truck/wrecker.

Use the p2p program in the technical manual section. It gives you the routing of all the air lines.

You can isolate on the vents behind the air filter. 4 of them converge there. Remove each line one at a time and see which one has air and report back which way it goes on the fram
Probably a Q2 valve or treadle ( brake pedal) valve are the obvious ones.

For the brake pedal you can remove the lowest air line going into it in the engine pay.with a 7/8 wrench. Thats the vent for the treadle valve

All vent lines are white in color on tracking it down

ill look in to the manual as you mentioned. i think i have all the manuals downloaded now, even the (CORRECTION), spricer, not eaton, docs on the ctis. does that p2p program have to do with the ctis junk?
since the ctis is NOT working properly, i have the cannon plug disconnected from the control module in the cab. i will attempt to replumb the system and go to a manual version, as someone posted on here some time way back, and file 13 the electronic crap.

 

[simp5782]

I'm robbing the parts truck for the stuff to get me dot legal, and the truck is in a field, that is softer than i thought. i put a 2' long section of r/r tie for shoring, then blocked the front up and let down on the crane cable and lowered it onto the blocks. the shoring under the front is almost level with the ground now. i used the crane to lift the rear as much as i could, but mostly took weight off the axels it seems. i repeated with the rear as i did with the front, and the 3 rear tires I'm taking off had sunk about 4"-6" in the ground.
even my stabilizer pads on the operational wrecker/crane, sunk over the 3 hrs i was holding weight of the canned crane.
im gonna take weight off the rear again tomorrow, but I'm gonna get 3 12" sections of whatever will fit over the studs, but will go through the stud holes in the rim. plus put the bucket on my tractor and dig out below the tires and try to slide the assy, over the pipes and into the bucket.

these things are NOT 1 man friendly. i might be better off getting an M88 track recovery track. only down side, its not as useful as the crane truck/wrecker.





ill look in to the manual as you mentioned. i think i have all the manuals downloaded now, even the (CORRECTION), spricer, not eaton, docs on the ctis. does that p2p program have to do with the ctis junk?
since the ctis is NOT working properly, i have the cannon plug disconnected from the control module in the cab. i will attempt to replumb the system and go to a manual version, as someone posted on here some time way back, and file 13 the electronic crap.

The p2p is a actual program that has the wiring and air diagrams that are interactive and pin coded for wiring

 

[charlesmann]

The p2p is a actual program that has the wiring and air diagrams that are interactive and pin coded for wiring

im not seeing the program. do you have the manual number? i can see wifi can download the manual. i did see a test in the troubleshooting section talking about sec not holding air, no major leaks, air can be heard venting into the intake stack, brakes applied. the thing is, i can only hear the air being vented when disengage the t-case pto. other than that, i can't hear air leaking. ill have my wife listen and see if she hears anything out of the sorts. but even in my deaf state, i can still hear noises that even she can't hear.

 

[simp5782]

im not seeing the program. do you have the manual number? i can see wifi can download the manual. i did see a test in the troubleshooting section talking about sec not holding air, no major leaks, air can be heard venting into the intake stack, brakes applied. the thing is, i can only hear the air being vented when disengage the t-case pto. other than that, i can't hear air leaking. ill have my wife listen and see if she hears anything out of the sorts. but even in my deaf state, i can still hear noises that even she can't hear.

Use soapy water in a spray bottle on lines. Not ears. The cotton jacket hoses can leak right thru the hose and you will just see lots of tiny bubbles

 

[simp5782]

Very bottom link.

It is not a manual. it is a digital thing the military did

TM's for the 939 series trucks

Listed below are a number of the TM's for the 939 series trucks. To save them to your computer, right click, select "save as" LO9-2320-272-12.pdf LO9-2320-272-12 Lubrication order for the M939 series trucks. June 1990 TM9-2320-272-10.pdf TM9-2320-272-10 Operations manual for the M939 series...

www.steelsoldiers.com

 

[charlesmann]

Use soapy water in a spray bottle on lines. Not ears. The cotton jacket hoses can leak right thru the hose and you will just see lots of tiny bubbles

that was my first step in the troubleshooting. but i think my wife found it. the rear winch tensioner chamber, or in that area. i didn't even spray in that area, but will tomorrow when there is daylight.

thanks for the link.

 

[charlesmann]

nope, no joy. that program doesn't interact well with a mac, even though i have windows, it still won't open. oh well, ill do it the old fashion way.

 

[charlesmann]

for others out there, i got 2 18" sections of 3/4" black pipe/conduit, and it works alright. I'm having 2 rh and 2 lh bars/tubing machined to fit through the rim hole, and threaded for the studs.

after getting it jacked up, i burped the nuts off, and walked the tire off, but had to do some jiggling to get it over the hub flange and bam, wheel assy. was off. rolled the spare over, walked it over the pipes, and used a 24" pry bar to help get it the rest of the way, the jack had settled just enough i had to used the nuts to pull the assy. in place. took a whole whopping 15 minutes from burping the nuts off, to tightening the nuts up.

BUT!!!!!, i pulled a stupid, and forgot to pull the front wheel counter weight off, AND, installed the tire backwards. getting ready to jack it up enough to pull the tire the rest of the way off and turn it around.
lesson learned, pay attention of which way things are coming apart and going back together