!991 Prevost Coach Air

muldoonman · July 19, 2011, 10:38:49 AM

Fixing to hire someone to put Freeze12 in R12 system. He is a mechanic that has spent his early life with Stewart Stevenson. It has The drivers and central air. I bought (2) 30lb. bottles of freeze 12 over the weekend to make sure I would have some in the future. Mr Bob said it would take about 27 lbs. to fill. I couldn't find a soul in West Texas to do the job but found this gentleman's son that said he still works on The Detroits in this area. is there anything I should be looking for other than leaks? What pressure on high and low side should we be looking for? Wish me luck.

robertglines1 · July 19, 2011, 02:16:38 PM

Your ac guy should have answers. hopefully it will still have partial charge. fingers XXXXXX if not next hopefully will hold vacuum . if not he will pressurize and look for bad hoses/seals. Wish you luck. Bob.

Joe Camper · July 19, 2011, 03:07:28 PM

If the system has been compramised for some time you will definatly have problems created my moisture. It will manifest itself by clogging the screens at the expansion valves with scale and rusty bits.

You should flush the entire system first I would buy 2 new expansion valves.

I would also replace every o-ring in every hose end.

There is a solonoid next to the dryer in the condensor bay that is notorious for leaks and I would also get that dryer in there replaced too.

Another thing would be the brushes in the blower motors for the evap and condensor.

The brushes in the evaporator blower motor wear out twice as fast as the condensor blower motor cause the evap blower also runs in the heat cycle in winther and the condensor blower motor does not.

You do not wat to ruin those motors they are 1000 bucks

JohnEd · July 19, 2011, 03:31:51 PM

IF it has sat discharged for a period I would have heart burn. You have back-up OTR AC from your gen powered house air system so that isn't a crisis issue. I would replace the dryer/filter module with out thought. I would also try real hard to add a dryer filter up at the expansion end with those tiny valves being as easily plugged as they are and that is whether they are replaced or not and the smart money says to replace them. The guy with the inside info on the valve/solenoid has some wise advice given he is familiar.

Freeze uses the same oil as R12....verify that.

If this system leaked down 28 pounds of freon in a year you really need to replace the seals and FIND ALL THE LEAKS.

Good luck with this project.

John

robertglines1 · July 19, 2011, 03:41:56 PM

Little background here. Bus sitting in storage since 95. Bought at auction. all is known is ac is not cooling. Owner new to buses is trying to learn. 56,000 miles pro conversion. Might even have partial charge? Has hvac guy coming to diagnose. So is trying to understand general principles and capacities. I'm for one wishing him little trouble and keeping fingers crossed that the previous owners heirs by starting and exercising systems at least preserved some of the system. If worst come to worst. then all of the above will have to be done. Good luck and hope it shines on you. Bob

luvrbus · July 19, 2011, 03:59:50 PM

Just my bucks worth Prevost on their Hvac systems are like everything else they do that system is very complex and over engineered for a 9 ton unit with all the electrical and valves they use he may just have electrical trouble but I doubt that part but pretty sure he will have a few electrical problems it really takes somebody that knows what they are doing on that system.
You can spend some buck with somebody not knowing that system been there done that on mine lol and I was the one doing the work
Do any of the lights working on the system that you know of

hope it works for you
good luck

muldoonman · July 19, 2011, 04:20:30 PM

Ac guy stood me up. He had a field job. He said tomorrow afternoon. We will see. If not, I think I will drive the coach to my place between Austin and Houston. Leave in early morning and hope for the best. Mr Nick gave me a number for AAP and they gave me a number out of San Antonio and I called this afternoon and they said they worked on the Cruise airs and bus air. We will see. Thanks for help.

Glen

Ps.
Buying a coach that has been sitting for years has really been eye opening. Ah but she drives like a dream and looks new to match. I've got the fever boys.