Air Reservoir Safety valve

How do you check safety valve on the lefthand air tank. Do you depress or pull the small pin, and should it release air when you depress or pull it. The ord part number is 7533854. I'm at the stage of restoration where I have the cargo body off and everything is accessable,and if it is not working I would replace it.

I'm puzzled. I've owned at least four M211s and one M135, but I don't recall that item. Might have been there and I just didn't see it. I suppose if you pull the pin, air will releease. If it's mounted on the bottom of the tank, you might get water first.

Joe,
The valve is mounted on the top of the tank. Seeing that I have the cargo body off , I would want to make sure that the valve works, no sense in not checking it out seeing that it is so accessable right now, don't know what pressure the tank was tested to.

By the way what what pressure does the compressor cut off at ?



Tony

My M35A2 goes to about 120 psi and I think your truck is the same. Being on top is why I never noticed it on the trucks I had. I guess all you have to do is bring the air up and pull the pin and let some air out. The ones I did have on my civvy trucks had a ring on the pin. I don't know the pressure rating of the tank, but I kind of doubt that the compressor could create enough to blow a tank. Never heard of one blowing anyway.

Joe,

The ring on the pin is a petcock (bleed valve), originally on the M-135 there is a turn type petcock on the tank, lower part, for bleeding the accumulated water. This valve can be replaced with a ring & cable petcock ( call cable drains) so you don't have to crawl under the truck to bleed the water from the tanks.