M931 rear service air conection

[valhalla]

No air on blue service conection..is there another valve somewhere...red engr side good ...thanks

 

[Evil Dr. Porkchop]

Just to make sure, you're pressing the brake pedal when you're checking the blue side right? That is just for service brakes.

 

[Lukes_deuce]

Just to make sure, you're pressing the brake pedal when you're checking the blue side right? That is just for service brakes.

To be honest, I thought my service glad hand had something wrong with it the first time I went to check it. But I did some research and then attached an adapter and 50 foot of hose so I could check it in the cab while applying the brakes. Hard to check it when you have to be in two places at once!

 

[simp5782]

To be honest, I thought my service glad hand had something wrong with it the first time I went to check it. But I did some research and then attached an adapter and 50 foot of hose so I could check it in the cab while applying the brakes. Hard to check it when you have to be in two places at once!

When applying the brakes with the rear service valve in the open position. You should drop air pressure consistently. Most of us have gotten in our trucks after unhooking a trailer and forgot to close the valve. Appling the brakes with an empty truck then becomes a little interesting.

 

[TechnoWeenie]

Most of us have gotten in our trucks after unhooking a trailer and forgot to close the valve. Applying the brakes with an empty truck then becomes a little interesting.

Nuh uh... Never... I've never done that...

 

[valhalla]

Ok not a truck problem maybe Trailer is iffy (1061a)...crossed over outher air line and locks up Trailer brakes....Switch back to normal hookup no Trailer brakes ...Johnson brake has no effect...ideas....thanks in advance

 

[red]

Have you turned the 90 degree hand valve at the service brake air line connection?

 

[valhalla]

Yup...

 

[155mm]

Mine has a red valve and blue valve that shut of the air at the bottom of the pogo stick right on top of the deck, so that when you pull a pintle trailer all your air doesnt leak from your 5th wheel trailer hose. Photo to come in the light tomorrow.

 

[valhalla]

There closed....rear gladhand valves open

 

[155mm]

I will look at mine tomorrow to see. I will bet there is just a T under the 5th wheel air hoses that directs air to the rear.

 

[valhalla]

I have air to rear conections, they are functioning properly ,Trailer just does not seam to have brakes ,I have applied air to Trailer and it locks up brakes , there is air in tank on trailer. will drive it on road tomorrow and see, adjustment some where maybe...thanks for replying

 

[simp5782]

download the P2p program in the TM section or in the sticky section at the top of the 5 ton section. It will help you track down air lines. The rear service line comes up the frame rail and has a connection point right where the bolts for the bogie are (the rear end hold in) then it comes up the frame rail to a check valve on the frame in front of your drivers floor. It is near the little cross member that runs under the truck where your front driveshaft center shaft bearing bolts to. Smack it with a hammer. You can also take shop air and add it to the front service gladhand and see if the brakes activate. If they don't then you have a check valve problem. The front service and rear service meet there and get their air from the treadle on hose 200.

 

[valhalla]

Thank you sir I think this may be the gremlin

 

[simp5782]

Thank you sir I think this may be the gremlin

Also take off a treadle valve line and spray some WD40 in it. They can be sticky.

 

[155mm]

The T from the 5th wheel to the pintle appears to be at the tractor protection valve which is located on the frame just to the front of the air dryer directly below the pogo stick. That would be another place to check.


https://www.youtube.com/watch?v=-1vA1EnNJZ4

 

[jaws4518]

I think I might be having this problem? I want to use the service side air to run some air tools. The valve is open but no air? So do you have to have the brake peddle pressed to release air? I think I tried that, but no air. If so, do I need to create some type of AUX bypass to make a constant supply of air?

Just need someone to point me in the right direction for best way of using truck to supply auxiliary air.

 

[simp5782]

I think I might be having this problem? I want to use the service side air to run some air tools. The valve is open but no air? So do you have to have the brake peddle pressed to release air? I think I tried that, but no air. If so, do I need to create some type of AUX bypass to make a constant supply of air?

Just need someone to point me in the right direction for best way of using truck to supply auxiliary air.

You use the passengers rear side emergency port to run tools. And it won't run em long. The drivers side rear service port only activates with brakes

Sent from my SM-G935P using Tapatalk

 

[jaws4518]

Thanks! I'll test it out. I guess I can add a 25 gal auxiliary tank on the emergency side if needed. Does it need to be isolated at the end with check-valve and manual cut-off valve? Of course, don't want it to interfere with emergency brake reservoir. I'll be looking a the TM air schematic, but give me your thoughts on this. Do or don't....?

 

[Gunzy]

I don't think the Johnson lever has any affect on rear line connections, just the 5th wheel trailer connections.