anatomy of the pesky gladhand/emergency glad-hand valves

[Lmtv772]

So I replaced the gladhand and emergency gladhand valves under the cabin. And the emergency gladhand stopped leaking. Now I had to satisfy my curiosity and took a valve apart.
a couple of views of the valve, I took all the fittings off.



this is what the inside looks like
and the inside of that large cap
inside the cap is a clip and a membrane
this is what most likely the culprit is,as far as leakage is concerned. a dried out damaged membrane.

I'll take the other valve apart and see if there is something like a check valve somewhere.

 

[Lmtv772]

I took apart the second valve and it looks the same way inside, as the first one did. The membrane is torn.
There was no need to dissect the 3 rd valve, it was kind of obvious already.
The valves I have replaced them with made a clanking sound when I moved them left and right. It seems to me , that they have changed the design and put an actual valve inside???
Anyway, if you have a gland hand leak at the Emergency gladhand and the air pressure goes down rapidly when you press the brake pedal, then this is your first spot to check.

 

[Ukraine Train]

How much are the replacements? Seems like good preventative maintenance.

 

[Lmtv772]

There are two designs
a diaphragm valve as in the LMTV KN25060
Repair kit for diaphragm valve RN11V
or a shuttle type valve as in the MTV KN25061

 

[Blackmagic94]

Can just the membrane be replaced?



Also I noticed that compared to my M923A2 trucks they have an on / off valve for the glad hands, do the FMTVs do this as well or as soon as you connect you have power?

 

[Lmtv772]

FMTV's have a on off valve.

top one is for trailer supply . Lower lever for park break
And the membrane can be replaced with the repair kit for diaphragm valves part #RN11V, I've posted

 

[10Lugger]

Can just the membrane be replaced?



Also I noticed that compared to my M923A2 trucks they have an on / off valve for the glad hands, do the FMTVs do this as well or as soon as you connect you have power?

Yes, I used kit from Haldex #RN11v. Note: this will only work on 1 of two possible valve designs though.