Should this gladhand have a valve?

[sed6]

The front service gladhand on my M925 doesn't have a shutoff valve. The other three do. I presume it was removed and never replaced? Do I need to buy a specific valve or will something from my local hardware store work? And while I'm asking I see the emergency is always painted red but I've seen the service side painted either yellow or blue. Is one color correct?
Thanks!
-Scott

 

[Coffey1]

No if you look at the cover it has a vent. That line charges the truck when you put air to it from another truck.

 

[Andyrv6av8r]

If that line doesn't vent, your brakes will lock up.

 

[sed6]

Wow! Glad I asked. Thanks! Any ideas on colors?

 

[sed6]

I'll also point out that I looked at the -10 before asking and in the PMCS section it shows a valve there. I realize that the illustration is for illustrative purposes and maybe they should have used the other corner as an example. I'm going to go with what you guys said. I've referenced the - 10 & - 24 a lot these last two weeks (FIRST thing I learned on SS) and this is the 2nd or 3rd 'error' I've found.

 

[Coffey1]

That valve is yellow on mine red other side

 

[Gralmk]

Service = Yellow. Emergency = Red

Sometimes you can fine Blue on some instead of the yellow, it was never my choice with 41 years in!

But your truck your call!

 

[sed6]

Thanks guys!

 

[Coffey1]

Now that I think about it the tm is correct unless its pointing to that valve. You still need to check to see if yellow and red are closed on the rear. The valve they are showing looks to be on driver front at steer gear box and they figure you can't close a valve that's not there.

 

[zebedee]

Service = Yellow. Emergency = Red
Sometimes you can find Blue on some instead of the yellow

Blue is a modern civi thing - like cup holders and 'lectric windows. Pfffff I say.

 

[M35A2-AZ]

No valve!!!!!
When I first got my M923A1 I was new to 5 tons, the truck was just out of rebuild in 2010.
I was washing it and I noticed the valve on the front service glad hand was open, so I closed it and kelp on washing.
Then later in the week I drove the truck to town and started having brake problems unknowing that the closed valve was the problem.
When you drove the truck the brakes would start to drag then lock up.

When you release the brakes a little air needs to vent out the front glad hand, but if it does not it starts to build up and starts to apply the brakes slowly.
That is my newbie story on 5 tons.

 

[painter paul]

Another confusing thing is that all of the older MV air shutoff valves are opposite of the civi valves in that off position is with the handle in line with the piping. I have found some of the 939 series valves are the same as the civi valves where off position is with the handle at a 90° angle to the line or piping. Arrrrgg, just have to test them to be sure.