M936a2 problems

[Military176]

Just bought and m936a2 wrecker that's been sitting got it re primed and started today and it runs good but only builds air pressure on the secondary side breaks won't unlock can't hear any real air leaks but one that I fixed behind the cab I don't have any real experience with air breaks I'm totally confused as to why it has secondary air pressure but no primary air that and the hyd tank on the wrecker is low does anyone know what it takes for hyd fluid?

 

[simp5782]

Just bought and m936a2 wrecker that's been sitting got it re primed and started today and it runs good but only builds air pressure on the secondary side breaks won't unlock can't hear any real air leaks but one that I fixed behind the cab I don't have any real experience with air breaks I'm totally confused as to why it has secondary air pressure but no primary air that and the hyd tank on the wrecker is low does anyone know what it takes for hyd fluid?

10w hyd fluid

Under the truck. Pass side. Right in front of transfer case is a tank on the inner frame rail. Has 2 valves on it. One front one top make sure they are both open.

Secondly check your pressure at the tank directly cause it could be a stuck gauge

 

[Military176]

10w hyd fluid

Under the truck. Pass side. Right in front of transfer case is a tank on the inner frame rail. Has 2 valves on it. One front one top make sure they are both open.

Secondly check your pressure at the tank directly cause it could be a stuck gauge

Thank you ill get some fluid for it tomorrow

I'll cheack that when I get back to it tomorrow afternoon it's about a hour away right now

And ill cheack that but at the drains for the air tanks the top and bottom valves have no pressure at them and the middle 2 do

 

[Military176]

Did that didn't change anything till i did it several times and cleaned both cheack valves got good air pressure and now the truck dies with put in forward gears unless the t case is in neutral and the pto will run the wrecker body. Breaks on rear axles seam to be disengaging visually watching them. I'm at a loss yesterday it would try and move both ways now nothing in reverse and it dies in any other gear

 

[simp5782]

Did that didn't change anything till i did it several times and cleaned both cheack valves got good air pressure and now the truck dies with put in forward gears unless the t case is in neutral and the pto will run the wrecker body. Breaks on rear axles seam to be disengaging visually watching them. I'm at a loss yesterday it would try and move both ways now nothing in reverse and it dies in any other gear

Make sure button on the transfer case lever is out and that your power divider that runs the wrecker is disengaged. If it's not it shuts the truck down

 

[Military176]

Make sure button on the transfer case lever is out and that your power divider that runs the wrecker is disengaged. If it's not it shuts the truck down

Button definitely clicks and returns and the power divider lever I've tried with both ways no difference

 

[simp5782]

Button definitely clicks and returns and the power divider lever I've tried with both ways no difference

Undo the linkage from the transfer case itself and make sure it's moving the full range of motion . Just had a customer that bought a truck doing that And it was the lever position

 

[Military176]

Undo the linkage from the transfer case itself and make sure it's moving the full range of motion . Just had a customer that bought a truck doing that And it was the lever position

Well came back to it today and now it wont turn over with good batteries no click nothing update ignition switch is bad

 

[Mullaney]

Well came back to it today and now it wont turn over with good batteries no click nothing update ignition switch is bad

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You might also have a PCB box on the firewall going bad. There are a couple of solenoids and a board in that little box. There is a rebuild thread on here somewhere. AND, @kendelrio just had that problem on his 5-Ton Cargo and he has a thread with a video link that explains fixing it.

Electrical issue on 1990 M923A2

All- Took Bertha to help my cousin move a bus (No big deal, never put her in low and never locked in the front wheels). ANYWAY.... I shut down to visit and when I got back in to start to build air..... nothing..... I checked my grounds and battery cables and tightened them all just to...

www.steelsoldiers.com

Hope that helps...

 

[Military176]

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You might also have a PCB box on the firewall going bad. There are a couple of solenoids and a board in that little box. There is a rebuild thread on here somewhere. AND, @kendelrio just had that problem on his 5-Ton Cargo and he has a thread with a video link that explains fixing it.

Electrical issue on 1990 M923A2

All- Took Bertha to help my cousin move a bus (No big deal, never put her in low and never locked in the front wheels). ANYWAY.... I shut down to visit and when I got back in to start to build air..... nothing..... I checked my grounds and battery cables and tightened them all just to...

www.steelsoldiers.com

Hope that helps...

We jumped the starter and it fires right up and runs but now it moves breaks are frozen so I'm going to pull the wheels and the brake shoes and get them freed up

 

[Mullaney]

We jumped the starter and it fires right up and runs but now it moves breaks are frozen so I'm going to pull the wheels and the brake shoes and get them freed up

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You have plenty of air according to the primary and secondary air gauges?

You are on the other side of the country - but here we have had a lot of rain. Brake shoes have been known to stick to the drums in high humidity and rainy weather. A simple "love tap" with a 3# hammer on the bottom shoes - with the brakes released and the wheels chocked - might solve that.

 

[Military176]

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You have plenty of air according to the primary and secondary air gauges?

You are on the other side of the country - but here we have had a lot of rain. Brake shoes have been known to stick to the drums in high humidity and rainy weather. A simple "love tap" with a 3# hammer on the bottom shoes - with the brakes released and the wheels chocked - might solve that.

Almost 120 on both primary and secondary
Rains a ton where I am too
I will try that on Monday before I go about trying to jack it up and pull the wheels I'm really not looking forward to doing that

Truck in low range with the front axle locked in ot will rock back and forth but it's definitely fighting the breakes front ones both squeal so that's where im going to start trying to free them up

Also attached a picture of how the truck was sitting for the last 8 years or so...

 

[Mullaney]

Almost 120 on both primary and secondary
Rains a ton where I am too
I will try that on Monday before I go about trying to jack it up and pull the wheels I'm really not looking forward to doing that

Truck in low range with the front axle locked in ot will rock back and forth but it's definitely fighting the breakes front ones both squeal so that's where im going to trying trying to free them up

Also attached a picture of how the truck was sitting for the last 8 years or so...

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Well that make it official!
You have rescued your first MV and that is pretty cool.

 

[Military176]

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Well that make it official!
You have rescued your first MV and that is pretty cool.

Thank you! Hopefully bring her home next week and tidy up everything on it get some new cables on it and then put her to work again!

 

[Military176]

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You have plenty of air according to the primary and secondary air gauges?

You are on the other side of the country - but here we have had a lot of rain. Brake shoes have been known to stick to the drums in high humidity and rainy weather. A simple "love tap" with a 3# hammer on the bottom shoes - with the brakes released and the wheels chocked - might solve that.

Also just noticed my profile still said Nevada lol I'm in Brevard nc think I got that fixed though

 

[Mullaney]

Also just noticed my profile still said Nevada lol I'm in Brevard nc think I got that fixed though

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Well neat! You are up there where all the waterfalls at stuff are.
There is a lot of fun, simple and enjoyable things to do up there.
Couple of really good BBQ places up there too.

My dog really enjoys swimming in the river that runs down along the highway towards Transylvania County. Or he used to. He is getting to be a little "gimpy" and it takes him a little more effort to get around these days... He still remembers the room we always stay in the Red Roof Inn.

 

[Military176]

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Well neat! You are up there where all the waterfalls at stuff are.
There is a lot of fun, simple and enjoyable things to do up there.
Couple of really BBQ places up there too.

My dog really enjoys swimming in the river that runs down along the highway towards Transylvania County. Or he used to. He is getting to be a little "gimpy" and it takes him a little more effort to get around these days... He still remembers the room we always stay in the Red Roof Inn.

Yeah definitely a few waterfalls here I hike a lot when I can and definitely a few good BBQ places in the area too. Cant beat it i think I've lived a few other places definitely better then the dessert in Nevada though.

closest red roof inn in about 20-30 minutes from my house I believe that's the one your talking about one of my dogs loves the river the other just watches him like he's nuts but they are both young yet

Wish I'd posted on here a little sooner I was in Charlotte for the autofair not to long ago

 

[simp5782]

We jumped the starter and it fires right up and runs but now it moves breaks are frozen so I'm going to pull the wheels and the brake shoes and get them freed up

Push the self recovery brake release under your steering wheel. If there is an issue with the power divider killing the truck in drive then the power divider still has those brakes locked.

Smack the pcb with a hammer, cold weather snaps or moisture days will cause a pcb to malfunction

Usually tends to happen a good hit when Temps drop below 55 or 60 for the first time in a while

 

[Military176]

Push the self recovery brake release under your steering wheel. If there is an issue with the power divider killing the truck in drive then the power divider still has those brakes locked.

Smack the pcb with a hammer, cold weather snaps or moisture days will cause a pcb to malfunction

Usually tends to happen a good hit when Temps drop below 55 or 60 for the first time in a while

Smacking the pcb didn't change anything havnt got the breaks figured out yet but found this ... both holes are blowing air and the ctis doesn't seam to be working this is beside the transfer case on the passenger side

 

[Military176]

And now the truck is dieing when putting into forward gears again