Air Conditioning

[Terry Neal]

Thanks Don for this info. Good things to consider. My dash air has
always been just average performance so I suspect the dryer needs
replacement as well as charging the refrigerant. As I recall, it is
still R12. I do have the eqpt to change it over to R134A though. The
condenser sits on top of the roof and I'll head up there to make sure
that it's clean & getting proper air flow.



Appreciate your sharing your experience on this subject. We'll be
seeing 100+ soon in Montana & I want to be ready for it.

Terry

Terry Neal

Bozeman, MT

82PT40 6V92TA

74FC34 6V53T











Don Bradner wrote:







There've been a few A/C discussions in various threads recently -

must be a calendar thing. I thought I would add my own.







I've always been very impressed with how well the overhead chassis air

cooled driver and passenger in Blue Thunder. In previous SOBs on really

hot days the dash air was never enough - had to run the generator and a

house A/C as well. Blue Thunder is one of the 90s with the condenser

back at the radiator rather than on top of the front cap.







10 days or so ago there was a big heatwave on the west coast, and I

turned on the A/C for the first time in a couple of months - no cold at

all, sigh. Ran the generator as needed to keep things decent, and

waited until we got home to check things out.







On top of the hoses as they leave the compressor are R12-to-R134a elbow

service ports. Both were loose, and a small amount of pressure on the

high-side fitting caused it to separate. There was no gas escape,

indicating that it was all long-since leaked out.







I assume that I am the culprit on this. I had to drop the pump in order

to disconnect one of the gate valves when I was searching for my

chassis heater problems, and I'm guessing I hit the fittings at some

point during the process. They are rather exposed and easy to collide

with.







A local outfit did the service, replacing both fittings and using 7-1/4

lbs of R134a. An expensive lesson, for sure, over $600 bottom line.







The records from the coach's second owner shows a $700 bill in July of

2001 for "A/C repair" so I'm guessing that may have been the original

conversion.







I know there are a number of folks who have posted that their dash air

does not work, and they just use the generator/house air solution. We

considered that, but even with the high cost of repair the economics

appear to be in favor of the repair route. Our generator pulls about

1/2 gallon per hour when doing light work like a single air

conditioner. At $5 per gallon that would mean $600 would run the A/C

for 240 hours. At most that would be a couple of years for us, and

probably less. We will be traveling to the East Coast in August, and

are likely to be in hot weather until we leave Florida in November.







I'll be sorry if it turns out that I have a leak somewhere else, but

I'm fairly confident that I don't. The tech put plenty of fluorescent

dye in with the refrigerant, and nothing has shown up anywhere.







Don Bradner



90 PT40 "Blue Thunder"



Eureka, CA