WRECKER AIR VALVE 936a2

[74M35A2]

Now THAT was funny. Welcome to the club.

 

[SLOrazorsedge]

I have that valve on my M936A1, however it does not lock the brakes? My truck also as the upgrade momentary push to release brake valve beneath the steering wheel under dash that I never understood what it was for as the brakes never locked. The auto idle up works fine while using the crane...so ya think a portion of my valve us inop?

 

[rumplecat]

My 936A2 has the hardware to go to the auto throttle but it has been disabled. I was unaware the system also locked the brakes?

 

[Swamp Donkey]

I have that valve on my M936A1, however it does not lock the brakes? My truck also as the upgrade momentary push to release brake valve beneath the steering wheel under dash that I never understood what it was for as the brakes never locked. The auto idle up works fine while using the crane...so ya think a portion of my valve us inop?

From the -10 Manual actual Page #3-33



I haven't found anything on the valve under the steering column in the TMs since it was a modification kit. I did pull the information below from a listing. I'm not sure if it's accurate because I can't find it printed anywhere else.

Brake Lock Override Kit M936/M936A1 Wrecker

Brake Lock Override kit for military 5-ton wrecker M936/M936A1. Includes Valve assy. hoses, fittings, bracket, nuts, bolts washers, etc, installation and drawing instructions. This kit will engage the air brake system into a locked position while using the wrecker boom or for parking purposes.

 

[M35A2-AZ]

My button under the steer wheel does work and when you have the PTO engaged you can press that to release the brakes to use the rear winch to pull you're shelf out I guess.

 

[Swamp Donkey]

I've got to quit looking at this wrecker stuff before I end up with one.

 

[M35A2-AZ]

I've got to quit looking at this wrecker stuff before I end up with one.

You will love it..

 

[SLOrazorsedge]

They are the best and most versatile truck of the M939 series for sure !!

 

[Csm Davis]

Okay here's the thing a lot of wrecker operators would disable the accelerator function so they could manually set the engine speed and I have seen this on 816, and 936, A1, A2, all versions. The brake release is for letting you move with the rear winch. A lot of the trucks are setup to and by the drivers to function as they want and need.

sent from my decrepit fingers

 

[Scar59]

They are the best and most versatile truck of the M939 series for sure !!

The Swiss Army knife of military trucks.

 

[JARR Towing]

I have a 90 m936 a1. When I engage the Pto for the crane air is coming out of the end of the Pto control valve and also Out of the intake stack. Also when you hold breaks at a stop light I'm losing air out of the intake stacks. Could these be related? New to the military vehicles and any help would be great

 

[86m1028]

What rpm does it bump it up to ?
I have an A2 with that valve & mine does not idle up.

 

[JARR Towing]

What rpm does it bump it up to ?
I have an A2 with that valve & mine does not idle up.

Well currently revs to limiter to compensate for the air leaking out of intake stack and power divider bleeder

 

[86m1028]

Well currently revs to limiter to compensate for the air leaking out of intake stack and power divider bleeder

I should have worded it differently.
When it's operating correctly what does it auto rev too ?
Im new to the military wreckers also.
I've been reading the tm's, had read about the auto lock brakes & brake override, understand them but didn't really see any info on the auto idle up (haven't dug very deep to see if mine has it or not, I do know if I DO have it, it ISNT working)
Did read the warning on the door about trans damage if left at idle & using the pto.
Im just trying to learn what options there are & the best way (for me) to operate mine.
The wrecker owners & guys that used them in service, have a lot of experience with them, know some good short cuts & still stay safe with them.
Doesnt matter how much you know, there is always something to be learned.
JARR Towing this isn't an attack on you.
Im betting you have learned a lot of little tricks of the trade with the civi wreckers !

 

[JARR Towing]

I don't know when it's operating correctly what it revs to, bought the truck 3 weeks ago and totally new to it. I know civilian wreckers you don't want to idle past 1500 rpm Max

 

[SLOrazorsedge]

I have a M936A1, the throttle kick up is part of the PT pump. When you engage the PTO for crane operations it auto advances the throttle to 1500-1600 RPM. Once engaged you pull the hand throttle all the way out and lock it.

 

[JARR Towing]

Slo do you have any experience when Pto engaged it loses air and revs high to try to build

 

[M35A2-AZ]

I have a 90 m936 a1. When I engage the Pto for the crane air is coming out of the end of the Pto control valve and also Out of the intake stack. Also when you hold breaks at a stop light I'm losing air out of the intake stacks. Could these be related? New to the military vehicles and any help would be great

With your stop light air leaking, Sound like you have a service side brake diagram that is bad.

 

[JARR Towing]

I'm replacing all of those today, but the Pto still throws me off. I know on my truck engaging the Pto locks the breaks up so that could be related, but the power divider valve is leaking out of the vent cap on it.

 

[86m1028]

I'm replacing all of those today, but the Pto still throws me off. I know on my truck engaging the Pto locks the breaks up so that could be related, but the power divider valve is leaking out of the vent cap on it.

The brakes locking when the pto is engaged is normal.
The brake release under the steering column is for self extracting with drag winch.