alcohol evaporator on m939

[yellowstonebill]

I live in Bowman North Dakota and just had two M939's delivered from the south on a step deck. It was hard to get them off of the trailer because the brakes would not release, I believe the air lines were frozen due to moisture in the lines and the 3 degree temps here. I looked at the TM and it talks about the alcohol evaporator but does not give any information about adding alcohol to the air system. Does any one have a idea of how to add break line drier to the air system. It would be appreciated.

 

[sandcobra164]

Are they ABS equipped trucks? Look for a little yellow bulb to the right of the starter switch. If so, they already have an air drier but it likely needs some maintenance. If it doesn't have an air drier, it's easy to retrofit one and there's a gentlemen that sells good ones in the classifieds on here for a little under $200 for the complete unit. You'd still need to get some fittings and tubing to plumb it in but it's probably not too bad a job. It mounts just forward of the intermediate rear axle. Even after fixing or adding a dryer, you still need to build air and drain the air tanks a few times to get the rest of the moisture out of the system. Since you have the TM, you should know the correct order to open the drain valves next to the passenger step. If you haven't found it, the most important step is to open the air valve second from the bottom first. That's the one plumbed to your "wet" tank.

 

[juanprado]

The original trucks had a small bottle on the left side of the engine towards the firewall. That is where the alcohol goes for NON Abs trucks.

When ABS was added, the drier takes the place of the bottle as they are not to be used together. Sometime the bottle is not removed like mine when the MWO to add abs brakes was done.

Your drier likely needs to be serviced with new coalescent and desiccant filters. Frozen ppv valves are know to have given many problems also.

I would recommend using the newest tms posted here on ss as they cover abs brakes. The originals did not.

 

[yellowstonebill]

Thanks for the great information. It does have ABS. It is still at the tractor dealerships dock where I unloaded it. I will blow it down on Saturday when it is suppose to be 35 degrees. Thanks again.