Eaton RTLO-16913A range issue...

This question is unrelated to my shifter head question on air lines...

I had the Range (Hi/Lo) Servo and Splitter Servo units rebuilt with new O-rings and a new piston.
The shop did a good job, but when we aired the truck up I only had splitter function.
The Range paddle didnt do anything but hiss air when the lever was flipped.

The tech took the cover off and was able to manually move things.
They were not too tight at all.
He put the cover back on and we tried again and it worked.

It worked fine the rest of the day (last week Wednesday).
I then parked the rig.

Today, almost a week later...I went to head back out and discovered I have no RANGE function again.
I hear air when I flip the paddle up or down but no 'clunk' out of the trannie.
The splitter still functions just fine.

Anyone have any tips as to what this could be or how to troubleshoot this?
I had no issues like this before the rebuild but at the same time, not ready to blame the guys that did the work.

They are offering to come out to me and replace the air regulator at no cost (parts or labor) as something to try..
....but I'm not sure that will do anything.

Thoughts?

 

My tech spoke to Badger Transmission repair today.
They suggested the sealant used on the gasket (when used as directed by Eaton)
can come in contact with the piston and cause a 'frozen' state...

They have found that it binds the piston in place and the air pressure cannot
overcome it?? - So the idea is to remove the cover plate, see if it was stuck and using brake clean, remove the stuff and reassemble.

I will find out more Wednesday. Seems plausible given the fact that when this first happened - the tech did remove the cover plate
and when reinstalled it worked for a few days. Until the rig SAT for awhile...and now it wont shift.

 

Turns out its a 'known issue' around trans shops here.
When you replace the cover/gasket on the range unit, Eaton says to use Hi-Tack on each side of the gasket.
When you do that, Hi-Tack can come in contact with the piston on the inside and cause binding.

Sure enough..the piston was hard stuck to the cover.
The tech took the cover off and cleaned/free'd up everything and we are AOK now.

The advice from Badger Transmissions was to not use Hi-Tech on the inside face of the gasket that faces the piston.
They stopped that practice about 4 months ago and their call-backs stopped.