Leaky Dash Tractor valve?

Get a spray bottle like this:


Put dish washing detergent and water in it. Spray all fittings, air bags, ect. You WILL find leaks this way.

I agree with the hissing probably being a brake chamber diaphragm, unless you are pushing in the red valve with the yellow without a trailer hooked up. If the valve itself is leaking, it will sound more like an air hose with a hole in it, it it's a leak some where else, the noise will still come from the valve, but will be more muted. As others have said, when you hear the leak, try twisting the knob around to see if that changes the sound. If not, check elsewhere before you spend money.

 

The air was coming OUT of the yellow valve.
Bashing it in and jerking it back out - stops the noise for good until I start all over...

I can go a week w/o any hiss and then have hiss every other time or so I release the tractor brakes. (I am running bobtail right now, so the red valve is never applied).

I got the new unit and finally transferred all of the fittings over to it.
I stopped tonight. Will work on it again in the AM and let everyone know what happens. With my luck, it wont be the valve...but my $ is on it at the moment...

 

In that case, it sounds like you found the culprit. Good luck.

 

Yea..indeed.

I like the quick-disconnect air fittings, especially when they DONT disconnect quickly..

Tried to get NEW ones. Nope. Not stocked at any of the dealers here.
So I will simply snip a teeny amt of air line and push them back in and re-use the fittings....

PS. What a pain it was to get this thing 'wrenched' out of the dash. I had to take out the main switch panel (as expected) but then the spaghetti mess of wires/air hoses and FILTH was amazing. Gee, I wonder what suddenly won't work once I fit the dash all back together...

 

Servicing the original valve with the maintenance kit is much less labor intensive and only cost $20 bucks.

 

The ancient Chinese secret to get them to release is to push the line into the fitting as you press the release ring (with an open end wrench). Then pull the line out.





















If that doesn't work... smack it with a ten pound hammer.

 

..yea, I discovered this. I presume you push the collar in and then shove the air line into it. Thats what I did with the sleeper air bags and they seemed to work fine.

PS. Had I known about a rebuild kit BEFORE purchase I might have opted to go that route. Yea, a hell of a lot easier for sure

 

Push the line THEN the collar... then pull the line out.

 

Right...but what about mating them?
Just shove the ol' line into it until it bottoms?

(gee...that sounded odd to say just now)

 

Yep, that's all there is to it. You may want to cut a quarter inch of the line off so it has a new surface to seal on--if there's enough that is.