Deuce has a low air leak

[yamabro]

I know. But TexAndy is right. and water in the system just causes corrosion and then you've got failure.

 

[m16ty]

The worst thing water in the system does is freeze in the winter. On a M35 you'll only loose brake boost if it freezes. On civilian trucks will full air brakes, you can loose all your brakes.

 

[yamabro]

Been there, Darn this Tn. weather warm then freeze, vise versa. I guess I should invest in some air line antifreeze

 

[tm america]

i have a quick release valve on the tanks on the one i am having trouble with.

this is most likely your problem they almost always leak.. i would switch back to regular pet cocks or 1/4 turn valves to fix that leak .. before i waist any of my time hunting down other possiblities..You probably need to adjust the air governor to .. but when you get done reading the tms on your truck you should have a good idea how to do that

 

[TexAndy]

Did you put any teflon paint or tape on the threads of new valves?

 

[1983M35A2]

Did you put any teflon paint or tape on the threads of new valves?

come to think of it no i didnt maybe thats it .thanks

 

[cyruscat]

After having my M35A2 a while I mentioned to my brother who owns and drives semi-tractors that my air would leak down overnight.

He laughed at me and said "that ain't a leak!"

But seriousely, I would like to make my system more air tight............

 

[Tlauden]

Man, 30 psi overnight... Must be nice, mines at zero within 6 hours of shutting her down, but it holds pressure going down the road so I'm a happy camper, maybe one day I'll get around to checking the whole system for leaks, one more thing to my to-do list...

 

[1983M35A2]

thank all of u for the info.

 

[Clay James]

Both mine will leak down half their air pressure in a few hours(never let them sit longer before draining the tanks). They hold air while driving so I don't worry about it much. I know where a couple leaks are but I'm doing the more important fixes first.

 

[1983M35A2]

thanks for all the help.

 

[SWoods]

You mentioned in post#8 not making over 80psi; check your belt. A loose belt can = low air pressure when running (I know from experience). like post#9 said you should be running at 100-120 psi.

 

[Jake0147]

how do i fix. after sets over night its down to 30psi.

If you want to fix that, you've got to break it first. If you want to make it better, you probably can. With a leak that slow, it could be ANYWHERE, and odds are you'll find that it's not so much one big leak, as the cumulative effect of a bunch of minimal leaks. Soapy water in a spray bottle and some quality time are in order. Spray anywhere there is air.

it never get above 80psi

Now that may well be a fixable problem. That's very low. Probably functional, but not what it should be. Does the compressor cycle as it should, mostly off and just replenishing the air from time to time? Or does it run all the time? Do you get the "woosh-pop" when the governor drops the unloader line anywhere from ten minutes to a couple of hours after you park the truck?

 

[1983M35A2]

You mentioned in post#8 not making over 80psi; check your belt. A loose belt can = low air pressure when running (I know from experience). like post#9 said you should be running at 100-120 psi.

thats the first thing i checked.

 

[BadMastard]

First, let me claim NOT to be an expert. What I can say is that every single time I fix a leaky hydraulic/air system it breaks somewhere else with the "new" pressure until I have replaced every component in the chain. Might just be me. Just in case it's not though, the first thing I'd replace is your gauge. A good measurement is worth it's weight in gold. And of course, good luck!

 

[Zepol95]

First, let me claim NOT to be an expert. What I can say is that every single time I fix a leaky hydraulic/air system it breaks somewhere else with the "new" pressure until I have replaced every component in the chain. Might just be me. Just in case it's not though, the first thing I'd replace is your gauge. A good measurement is worth it's weight in gold. And of course, good luck!

I fully agree...First strange thing - keeping 30psi at night? Unheard of from people that I know...plus, not creating +80psi...you'd have a problem that would be VERY obvious. Althought BadMastard claims not to be an expert, that is the most viable explanation I have heard so far..

 

[big1096]

Also, about it not going over 80 psi... Sometimes my gauge sticks at 90 and if I tap it, it goes up to 120 psi like it should. Maybe a little tap to see if it moves when it's pumped up.

 

[Jimma]

Yeah, 30 psi after sitting overnight is pretty good. Most trucks will be at 0 psi. The issue with draining them is to get the moisture, scum and oily stuff out. If you are running alot on a humid day you will be suprized how much moisture builds up in them. If you are doing it for the first time in a long time dont put your face under it when you blow the tanks. You will be wet and oily.

 

[1983M35A2]

thanks for the help.

 

[Katahdin]

Just read this in the 1965 TM and it cracked me up. So as long as your soapy air bubbles grow to smaller then 3 inches after one minute@100 psi, you're good-to-go!