Air pressure

[arkansas-jimmy]

I operate a roadside assistance company usually just for small cars and trucks, Sometimes I get call for the trucking companies. Which trucks and year made require some air pressure before the truck will even start. and where I can find more details how to add air to those truck so they do start.

 

[Mike]

You might run into a few trucks still from the 90's that have air start systems. Hopefully, they would have a dedicated air tank for the starter and you would just need to pressurize that tank. No idea what kind of fitting is used to connect to that tank, though.

You might see some old farm trucks still using an air starter, but even then, the likelihood is very slim. Maybe if they got a good auction deal on an old postal truck, otherwise it would be really old for you to see an air start system.

 

[Electric Chicken]

My '88 doesn't even have an air starter.

 

[Mike]

My '88 doesn't even have an air starter.

USPS had air starters on some of their trucks into the mid 90's. Can't remember the last time I seen an air start system, but they arent' totally gone yet.

 

[Mike]

Imagine this starting up beside you in the truck stop....

 

[mndriver]

That’s a blast from the past…

 

[Electric Chicken]

Imagine this starting up beside you in the truck stop....

My body makes those noises waking up.

 

[arkansas-jimmy]

You might run into a few trucks still from the 90's that have air start systems. Hopefully, they would have a dedicated air tank for the starter and you would just need to pressurize that tank. No idea what kind of fitting is used to connect to that tank, though.

You might see some old farm trucks still using an air starter, but even then, the likelihood is very slim. Maybe if they got a good auction deal on an old postal truck, otherwise it would be really old for you to see an air start system.

it was a 2019 freightliner, completely drained of all air, not an air starter, but the computer would not let the truck start unless it had some air pressure. I had a call like months ago.. Maybe the transmission had to have air pressure to send a start OK control to the computer so the truck would start. DT12-DT15 transmission I think.

 

[Electric Chicken]

it was a 2019 freightliner, completely drained of all air, not an air starter, but the computer would not let the truck start unless it had some air pressure. I had a call like months ago.. Maybe the transmission had to have air pressure to send a start OK control to the computer so the truck would start.

That's strange and kind of dumb on FLs part.

 

[Mike]

it was a 2019 freightliner, completely drained of all air, not an air starter, but the computer would not let the truck start unless it had some air pressure. I had a call like months ago.. Maybe the transmission had to have air pressure to send a start OK control to the computer so the truck would start. DT12-DT15 transmission I think.

I think I have heard about this a couple times. The guy in that video towards the end mentioned shift to neutral, even though he mentioned air pressure in the beginning. So really not sure what the air pressure requirements are on the Freightliner or any other manufacturer.

 

[Mike]

The shift to neutral fault was supposed to be fixed with programming on the 2020 and older models. That said, I have a 2021 model just like that guy and have had the same problem. Just cutting off the power for a couple minutes always takes care of it.

 

[arkansas-jimmy]

I call DETROIT DIESEL 13400 Outer Drive West Detroit, Michigan 48239-4001 800-445-1980 real helpful,, DT12 transmission are effected.. without 60 PSI the tech say.. the truck will not start.. or supposed not to start. Now I trying to sort out how can you get 60 PSI outside air into the system so the truck will start.

Cutting off the power,, but there was still air pressure in the truck?

The service call I had .. the truck had no air pressure what so ever

 

[AK7]

Why not just hook a airline to one of air tanks and pressurize the system that way.?

 

[Mike]

Why not just hook a airline to one of air tanks and pressurize the system that way.?

That’s the only way I can think of.

Curious about the 60psi thing, unless the transmission has its own tank. My air goes down below 60 sometimes when being loaded or unloaded, and every time I pump my brakes down or drain my air tanks. Truck always starts.

 

[arkansas-jimmy]

That’s the only way I can think of.

Curious about the 60psi thing, unless the transmission has its own tank. My air goes down below 60 sometimes when being loaded or unloaded, and every time I pump my brakes down or drain my air tanks. Truck always starts.

What type of transmission do you have? is it a DT12

 

[Rigjockey]

I thought you could hook a red line to a red line of another truck and it would put air into the tank of the truck with no air.
I saw a tow truck do this.

 

[Electric Chicken]

I thought you could hook a red line to a red line of another truck and it would put air into the tank of the truck with no air.
I saw a tow truck do this.

Makes sense if there aren't any check valves preventing it. Or would you simply push in the knob to open the flow?

 

[Rigjockey]

Makes sense if there aren't any check valves preventing it. Or would you simply push in the knob to open the flow?

I am not exactly sure but I think you would have to hold the red button in, in the dead truck or maybe it is red to blue?
I am not sure how he did it.

 

[Electric Chicken]

I am not exactly sure but I think you would have to hold the red button in, in the dead truck or maybe it is red to blue?
I am not sure how he did it.

Red button is for the red air line to release the trailer with constant pressure.

Brake pedal gives variable pressure through the blue line to activate service brakes.

 

[Rigjockey]

Red button is for the red air line to release the trailer with constant pressure.

Brake pedal gives variable pressure through the blue line to activate service brakes.

Yes. correct.