I have a 2007 Bounder 36Z with F53 chassis and 6.8 motor. Am having compressor replaced and the mechanic can’t locate the orfice tube or the expansion valve (depending which it takes) and can’t seem to find any info on it. Called REV they gave me a email to use and I still have no response from them after a couple of tries. If there is anyone who might have an idea please let me know. Trying to get drawings or as builds hasn’t been successful. Thanks so much in advance. Bill

I really appreciate your response. We were thinking the same thing but wasn’t sure as the lines lead to the hvac box in the hood compartment and couldn’t find any signs of orfice or expansion valve. I took it to my regular mechanic and he wasn’t sure about RV’s. So I guess we’ll try figuring  out how to get access to it from the inside. We were planning to replace the drier along with the compressor and flushing the system. Again thanks for your response. Bill

Thank you, this gives me an idea as what to look for. Now it’s time to get to seeing how the dash comes apart so we can get to it. It might be awhile as the old bones don’t get into contorted positions as easy as they once did.

Mine's probably not exactly like yours because mine's a diesel but is probably close.  I first removed a small cabinet and drawers that was fastened to the floor at the center of the dash where your 'dog house' would be.  I the removed the vertical close out panel to the right of the cabinet where the 120V outlet and A/C duct are located.  The screws were not visible because they were screwed thru or were covered by the carpet so I removed the carpet which we're replacing soon.  Note that screws were used on the two sides and staples on the bottom.  Only when the panel was removed could I see the 3 sided wood 'frame' that was attached to the floor, the right outer wall, and the cabinet.  Once this stuff was removed it was only a matter of disconnecting some wiring and approximately 8 screws that hold the evaporator case to the wooden 'firewall.'  NOTE that the heater case was separate and did not have to be removed.  All it took was some twisting and coaxing the evaporator case.  Just reverse the process to reassemble. Be sure to add a sealing puddy, etc. on the case where necessary. I have attached a couple of pics that might help you.  

Regarding reharging; I couldn't find a freon capacity anywhere so I used a pressure/temperature chart.  It was cooling well with 3 lbs. of 134a but 1 more lb. lowered my outlet temperature to 43 degrees.  Please let me know how it goes for you.

Mr. Orr, the fan is part of the evaporator case and it will come out as a unit.  The heater/defrost case is mounted above the evaporator case.  You might want to take a close look at the illustration in the Denso Parts Manual.  On mine, the screws were pretty easy to see and access.