Help diagnosing air and fluid leak.

I've got a couple of leaks on my deuce I need help diagnosing:

First is an air leak. There is a vent under the hood pictured below. When I turn the truck off, I can hear air venting from this tube. If I press the brake pedal, the venting stops.

The next leak is a diesel leak. It is coming from the area circled in the second picture.

I would appreciate any help diagnosing these problems and recommending a fix.

Thanks in advance.

1st pic is the vent from the air pack IIRC, second is the flame heater. The leak could be just a supply line or the injector itself. Dunno how cold it gets there, but you can block off the fuel feed for the flame heater and the leak will stop. As for the vent, try oiling the air pack. If it doesn't quit, the air pack will need some attention.

When I shut my deuce off the ?? vent leaks for about 10 seconds and then stops. I am not sure if it is the comrpessor unloader or another vent. It may be normal is what I am saying. Does the truck hold air for a while when you shut it off. They all leak air to an extent, but less is better.
As to the fuel leak, you can repair the flexible fuel line if need be. I have read in other posts that the 1/4 " air brake line is the right material for replacing the original "nylon" fuel return lines. If you search for fuel return line you will find a thread that discusses this very well.

rlwm211 said:

When I shut my deuce off the ?? vent leaks for about 10 seconds and then stops. I am not sure if it is the comrpessor unloader or another vent. It may be normal is what I am saying. Does the truck hold air for a while when you shut it off. They all leak air to an extent, but less is better.
As to the fuel leak, you can repair the flexible fuel line if need be. I have read in other posts that the 1/4 " air brake line is the right material for replacing the original "nylon" fuel return lines. If you search for fuel return line you will find a thread that discusses this very well.

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No, it doesn't hold air at all when I turn it off. It quickly bleeds down. The only time the air stops bleeding is when I press the brake pedal.

WillWagner said:

1st pic is the vent from the air pack IIRC, second is the flame heater. The leak could be just a supply line or the injector itself. Dunno how cold it gets there, but you can block off the fuel feed for the flame heater and the leak will stop. As for the vent, try oiling the air pack. If it doesn't quit, the air pack will need some attention.

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Thanks for the advice. How do I oil the air pack?

On the back plate there is a pipe plug, some are a male hex, some female and some allen head. Make sure the air is bled down to nada, just to be safe and remove the plug. Give it a few shots of Marvel mystery oil or air tool oil and put it back together. Build air and actuate the brakes a few times and see what happens...I gotta go look at the manual again. It's been a long time since i've been into it. It might be one of the seals up front, but the oiling is part of the upkeep. I'll post up some pics in a bit.


Here's a pic. You can see the pipe plug on the rear cover, at about 11 o-clock. The air leak COULD be starting from the valve on top where the J line comes from. Try the oil and see what happens.

mike mine also leaks just a little.. more of a hissss for about 2 seconds but holds air for days...oil up the air pack and first chance ill shot over an look at it... the truck at your house or up in the hills at the pole barn?