Any suggestions to find winter only air leak?

[belfert]

I've only had my Dina coach for a little over a year.  It held air for a weeks at a time all last summer.  Over the winter it would only hold air for a day or less.  This summer it is holding air for weeks at a time again.

Where would I look for an air leak that only occurs when the temps are below freezing?  I suppose I should service the air dryer since that hasn't been done in at least four years.  Moisture may be freezing in the air lines. 

I know it is unusual for most buses to keep air for more than day or two.  The Dina has torsion suspension so no air suspension except on the tag.  I like being able to jump into my bus and head out without waiting for the air to build up.

[buswarrior]

Hello belfort.

Expansion and contraction is your culprit. Cold seals shrink, and if they are getting old, let out the air.

Relay valve, foot pedal, one way check valves, not much to chase if you don't have air suspension and radiator shutters.

It may be one or a bunch of little bleeders.

If you are frozen up, you'll know about it! This isn't your problem in this case.

Yes, service your air dryer for preventive maintenance purposes.

happy coaching!
buswarrior

[larryh]

Brian don't forget you do have air brakes and if not enough air pressure you may not be able to stop if you have it does lead to brown stains. trust me on this.

LarryH

[belfert]

Brian don't forget you do have air brakes and if not enough air pressure you may not be able to stop if you have it does lead to brown stains. trust me on this.

The air pressure leaks down when it sits in the winter.  It stays up great in the summer.  It will air just fine during the winter and the pressure stays up during braking the same as during the summer.  The brakes were all replaced at C&J Bus Repair last summer and no air leaks then.  I talked to them about the air not holding last January and they just said almost no bus will hold air as well during the winter.

I don't believe it is a safety issue, but rather an annoyance.