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OTR Freon
Does anyone have a recommendation for servicing the OTR AC near Augusta, Ga to Columbia SC (i’m about 1/2 way between)
My Condensor motor won’t turn on and the tailtell light in the cokpit is on. Based on the troubleshooting I’ve done the low pressure switch is open so it is likely low on freon. Sytem worked last summer, quite working in the fall and I’m just now getting to it.
93 XL with freon 12 system. Does anyone have experience with the replacement product freeze 12 instead of the freon 12? I know the freon 12 is hard to come by.
Thanks
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13 Replies
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I used freez 12 in mine but thann i was advised that it was propane based and not safe to use so i took it out
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Joe,
Usually when the light is on and the condenser motor is not running it is either a tripped circuit breaker or the brushes in the motor are at the end of life.
Since Prevost has had different locations for the circuit breakers (and associated relays which also could be bad) I canot tell you where to locate them but look on the ceiling of the front bay, driver’s side or in a box inside the condenser compartment. Verify the breaker is OK, check for power through the relay and if they check out pull the brushes. I think 3/4 length is the recommended minimum.
If the coach is low on Freon the clutch might not engage. All those things you can check with a tester. If all checks out then have a tech put some gauges on it.
R12 is available and from reports here on the forum it is getting pretty cheap because almost all applications now are 134.
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I use R12 in both of my AC systems, dash air and CC salon air. I buy my R12 from Ebay. You will need a technician license to purchase the R12, all available from internet course ware providers. More expensive to purchase, but I like the performance.
The key is to assure you AC systems are leak proof. I replaced all the rubber AC hoses on my Prevost dash air. I have enjoyed a realiable AC system for 4 years until a recent compressor failure.
The rubber hoses in the rear of the coach seemed to be deteriorated more. The hoses in the front of the coach are protected and were in good shape. I used nitrogen to pressure the system to check for leaks. It was a pain to do, but had great results.
I have not experience with using R12 replacements.
Good Luck,
Hector -
Hector made an excellent point in that R12 is going to work best. First, I know there are drop in replacements, some of which are propane based. From reports they will work, but the fact the refrigeration industry has not embraced them would cause me to consider if I wanted to try them. David apparently uses a drop in replacement and perhaps he can share the comparative data. I would focus on the flash point compared to R12 and its efficiency.
Some coaches have been converted to 134A. Once you are confident the system is leak free that might be a consideration. The proper way is to replace all hoses, the expansion valve and certainly all the R12 compatible oil you can flush from the system. Using the proper oil along with 134A you will have a system with a readily available refrigerant for future service. However Hector’s point about performance is absolutely on target. Nothing is going to provide the cooling that R12 is going to. With 134A for example, even with a new expansion valve the system will have a loss of about 15% efficiency.
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Jon,
I checked the breaker (in the box in the condenser bay) last fall when it stopped worling. I will double check but the breaker wascclosed and the relays were ok. The clutch does not pull in. I recall checking the high and low switches with the high switch being closed and the low being open. Therefore my conclusion that it is low on freon. I don’t have any gages and can’t check pressure myself.
I have not checked the brushes but will do that also.
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I will check into the ebay freon 12 supply. Thanks for the tip.
I would prefer to stay with freon 12.
Does anyone know the system capacity (lbs)? I can not seem to find that information in “the book”.
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From memory: empty-around 28lbs plus oil. So would ck to see if I had partial charge and if it has leak fix it first. It is in book somewhere. Big expense that’s why everyone exhaust all other possibilities first. Guages are cheap in the overall cost picture..FWIW only Bob
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Around fittings for oil trace or signs of dirt/oil accumulation=sometimes is sign of slow leak that draws dirt to it. Also around seals on compressor. Should be AC clutch relay in rear electrical box-make sure it is good. Power to it and out when signal recieved. Your light on dash is probably correct but if compressor is not running there is no pressure to read. Again just trying to think thru your problem. Good luck. Might ck with a local charter company–they are usually glad to help and well equipped. Bob
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The system according to Prevost holds 24 pounds, but that is an approximate. Also as an approximation is when the system is charged, and running with all stabilized the red ball in the lower sight glass on the receiver should be in the middle of the sight glass.
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Have had Freeze 12 in my system for over 2 summers going on 3. Napa had a few bottles when I bought in west texas. Paid a little over 100 bucks for the 30 lb bottle. That is the reason I stayed with 12. Bought 3 bottles of the stuff. Wanted double the price with the 134. I’ve heard the propane based is no bueno. Works for me.
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R134a is at sams club for under $800 for a 30 lb can ,, when i got the freez 12 it was about $1090 for a 30lb equevent can about 18 lbs ,,,, You use about 1/3 less r134a than r12. not quite as cold . I have R134a in my dash air and evaporator is 46 degrees im happy and im in Florida .
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we use R 12 in our OTR we buy 30lb bottles on craigslist from a licensed refrigeration tech for $300/ bucks and have Stewart Stevenson pump it in
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Thanks everyone.
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