M923a1 air brake question

[Farmallmilitary]

Cool fact. Is it true in the marine trucks with axle lockers, you have to coast around corners when on pavement in order to have some give in the locker?

 

[ARYankee]

WHAT about those that do not do face book crap, your link is worthless to those because it REQUIRES a face book sign in

Oops. Sorry about that. I'll email it to patracy so he can load them onto the site.

 

[Artisan]

I am a noob too remember but from what I see alls a guy has to do is
take a data plate from truck "A" and rivet it to truck "B" and viola! You
just bred a new truck...

It may have started life as an M925 then got it's winch boosted ... I dunno...hard to say.

Sure seems wierd...

 

[commandojeff]

Cool fact. Is it true in the marine trucks with axle lockers, you have to coast around corners when on pavement in order to have some give in the locker?

Depends on if you are in low range or not. My truck does fine in high range with only the back axles moving the truck. It churns around corners sometimes. But once you get into low range, it is very hard to turn on pavement. I have no idea if I have lockers or not. I do know that in low range, it is solid. That is correct for lockers right? And if I am also correct, in high range with the front axle engaged, the lockers will kick in on straights and unlock around turns. I haven't tested it in high 6 yet, so I wouldn't know.

 

[commandojeff]

I am a noob too remember but from what I see alls a guy has to do is
take a data plate from truck "A" and rivet it to truck "B" and viola! You
just bred a new truck...

It may have started life as an M925 then got it's winch boosted ... I dunno...hard to say.

Sure seems wierd...

I agree. They are all the same truck. Just designated with different numbers so that the military can easily specify what is needed. Essentially they are all the same truck. Just like the 923 vs the 923A1 is duals vs singles.

From what I have heard before from other guys with the marine trucks. Your truck is a 923 but has the added winch controls if they were ever needed. The marine trucks are always different like that.

 

[ARYankee]

I agree. They are all the same truck. Just designated with different numbers so that the military can easily specify what is needed. Essentially they are all the same truck. Just like the 923 vs the 923A1 is duals vs singles.

From what I have heard before from other guys with the marine trucks. Your truck is a 923 but has the added winch controls if they were ever needed. The marine trucks are always different like that.

I have a Marine Corp truck as well and this is what I have heard too.

 

[Artisan]

Here is some more manual(s) fun.

I hope these manuals are looked at by folks here that are old pro's
and that they are verified the latest and greatest and uploaded to
the TM section here at SS. So far all the TM's and Parts n Tools files
I have found I believe are all 2012 flavor...

Sure do wish I could find a printer to print these files for cheap and
on good paper, maybe paper that is a bit water resistant even for
those times when your broke, on the side of the road and it is raining
kinda always seems to be the way deals! Ha!


All my files are labeled w/ what is it AND if possible the year of edition suffix'd at the end.

For the most part I am trying to stick to just the M939 series of trucks.

Parts n Tools #1

Parts n Tools #2

Parts n Tools #3

 

[Artisan]

Farmall I would love to see some pics of what your up too.

The way you did the tem air deal would be cool to see too.

 

[commandojeff]

Thanks for the manuals Artisan! I have read through some of the previous ones you posted and they seemed like they had a lot of good info in them. I liked those because they are actually field manuals instead of whatever the ones are here on SS. They seem more idiot proof in other words .

 

[dangerfieldinc]

lots of good info been learning alot

 

[Artisan]

My pleasure Jeff.

I hope SS staff see this stuff and verify the content and post for all in the TM area.

I am being VERY 'particular' if you will choosing what files I like, I am trying
to ONLY get my poop from the governemt so as to try to insure the files
are not adulterated in any way shape or form EXCEPT the way I am naming
the files...

If you pile all my files together and look at the names you will see the TM(or) number,
a brief description of the file and the date I believe of issue.

 

[Farmallmilitary]

Ok so i went to a big rig shop today and got a number 12 diaphragm but unfortunately they didnt have the 16. So i went home and put the diaphragm in which only took about ten minutes, which was faster than i expected. So i put everything back together and aired it up. No leaks coming from the front so I drove it forward about ten feet and applied the brakes and woa do they work. The brakes seemed sensetive, so I decided not to drive it around even though I REALLY wanted to. At least its not leaking. So next I will probably end up taking the large chamber off and taking it down to get it rebuilt by a pro. Artisan I read your comment about pics right after i finished doing it and i didnt take any. Sorry but I will try to take pics when i am working on the rear chamber. Any idea they could be grabby do i just need to drive it around a little to clean the drums and shoes? Thanks for the files!

 

[ARYankee]

WHAT about those that do not do face book crap, your link is worthless to those because it REQUIRES a face book sign in

Oops. Sorry about that. I'll email it to patracy so he can load them onto the site.

Well it turns out that it is already in the TM section: http://www.steelsoldiers.com/showthread.php?79228-TM-s-for-the-939-series-trucks

I knew that I had picked it up from somewhere but couldn't quite remember where so I looked in our 939 TM section and there it was. It is the M939_ABS_maint_sustainment_tng_std_handout additional handout for the ABS of the M939 series. That may help.

 

[Artisan]

Before I hopped in the drivers seat for the first time and old pro told me; "Those brakes will put your head into the windshield, be careful.." ...to wit I have been. Indeed, IMO they are "sensative", but, after you drive it for a while you get the hang
of them and you will be fine (so long as the system is at 100%) . Who was it that suggested a certified DOT Air brake mechanic
look at it? I do not know but even though I have no problems I will be paying said to give me truck a once over. After that
i will let the Mrs drive it...(just a little and off road! HA! )

I will give you a note of extreme caution, from experience, that being that if you get into the brakes hard in a corner you will quickly learn NOT to get on your brakes hard in a corner! Carry some TP and a change of shorts... If you do, and espically if
your in a downhill, decreasing radius turn, it feels like the front tires buckle in or something and then you let off the brakes and it
wants to jerk the other way...you gotta be there, you will see... NOT fun... I saw here a sig line I think it was where a guy says something like ; "Driving these trucks is the most fun anyone can ever have going slow..." and it is true, just cruise and if
people are not jumping in front of you and wanting to pass your driving too fast!

When these trucks were new many a man died in them. The military issued an order whereas NO ONE was to drive these trucks
faster than 40MPH PERIOD. I guess guys would get rolling and slam on the brakes and the tranny would lock up and kill the engine
and power steering would go away, I believe is the story, I am sure someone will correct me if I am wrong. So it was a while passed and all the trucks were retrofitted w/ ABS brakes... DO NOT DISABLE the ABS system my friend.

Just be careful, these things are HUGE and air brakes HAVE A LAG (Something you get taught in truckers School ) see, here we are back to that same ole same ole deal my friend...just sayin'. Knowledge is POWER.

 

[Farmallmilitary]

Ok I just didnt want to drive it if I was going to lock up the brakes. Before I drive it I will make sure the brakes are 100% but im sure i will get the hang of it. Oh I called our local truck driving school today and i plan to enrole in january. I cant wait to drive it.

 

[Artisan]

Here are some more links to files.

Operators Manual I am pretty sure this is the manual that would have come w/ the truck stock.
It would have been in a Cotton Duck Olice Drab holder then all went in the storage box
behind the companion seat. 2012

Hand Receipt BII
This has lists of parts that were Basic issue plus more for different trucks. 1990

 

[Artisan]

yep your gonna love it...THE SCHOOL! ...and driving the beasts
is a blast as well. When it is all done i guarantee you, you will say "I AM GLAD I DID THAT".
Do not go fast in 1st gear low range! I think there is a big warning someplace
about going more than 5-6mph in 1st gear low range.

I believe the 6 wheel drive is automatic in low, but I think you have to flip the dash
level for front axle engagement for high range.

 

[nf6x]

I believe the 6 wheel drive is automatic in low, but I think you have to flip the dash
level for front axle engagement for high range.

That is normally correct. But, it is possible for the front axle to not engage in low range, either from misadjustment or deliberate modification. After spinning my wheels some on my M923 shortly after I got it, I figured out by dumb luck that my front axle didn't automatically engage in low range when I flipped the dash switch withut thinking, and suddenly got traction. There is an air valve under the truck that gets actuated by the transfer shift linkage in low range to engage the front axle. Mine was a little bit out of adjustment. I decided that I liked it better that way, so I finagled things further to make sure the valve didn't get tripped in low range. Now I just manually engage the front axle in either range with the dash switch. I've heard that I'm not the only one who has done this, either. So, your front axle should engage in low range, but verify that it actually does if in doubt, and know that it's easy to disable that feature if you want to.

 

[nf6x]

I also agree with Artisan's comments about air brake lag. Air brakes are great, but they behave a bit differently than hydraulic brakes and they take a little getting used to. When I went to trucking school, getting a feel for the air brakes was one of the very first lessons. As I recall, we started off in a bobtailed tractor, which is about the worst case. It is really easy to lock up the brakes until you learn to cope with the different feel of them.

 

[Artisan]

GREAT tip on the front axle switch Mark!

I know w/ my supercab I like to drop it into low range w/o locking in the hubs
when I back trailers up my driveway...could work same concept w/ the 5tons...

I will have to look into how to do that mod...