In the process of getting my unit out of storage and ready for it's first trip this year, I have discovered another air leak. It appears to be coming from a cannister on top of the air dryer unit. There is a small hole on the side of the cannister that leaks air sometimes, not all the time. I only notice it leaking when the pressure is up and the engine is off. It is located on the right hand side behind the rear axle mounted on the outboard side of the chassis ( see picture). Thinking that the hole may be caused by rust, I was prepared to seal the leak when it suddenly stopped and didn't leak again until two days later. It seemed to stop after a purge cycle. After some research on the forum and my manuals, I still cannot pinpoint whether this is normal or that maybe the cannister needs replacing.

If this is a service item, is it something that I can do?

Any help will be greatly appreciated.

Sorry about the large picture. My travel computer's picture editor will not reduce the size.

That is a midland air drier. The air drier cartridge that has holes rusted in it. You screw it off the aluminum housing and replace it with a new cartridge. Any truck supply store should have one if they are still available. If not replace complete unit.

quote:

Originally posted by Paul Nance:
That is a midland air drier. The air drier cartridge that has holes rusted in it. You screw it off the aluminum housing and replace it with a new cartridge. Any truck supply store should have one if they are still available. If not replace complete unit.

Exactly... that is a spin-on airdryer element.

Thanks for your help guys ---- I'll start looking for one tomorrow.

Just thought I would post you up on this repair, having done most of it myself with some help from my son. We had to remove the whole unit from the chassis because there wasn't enough clearance to remove the cartridge. The "spin off" cartridge is misleading. I had to take the whole unit to a welding shop with a big vise mounted to a big metal table, crush the cartridge with the vise, attach a large C-clamp to the base and then twist the base from the cartridge. After almost 20 years the cartridge did not want to "spin off". The cartridge kit cost $140 and seems to work fine. My advice to anyone else who does this job is to prepare for the worst and expect to take several hours ( unless you have better tools than I do).

Thanks again for your help.