Community Forums

Riverside · 11-19-2009, 10:47 AM

Anyone know the refrigerant capacity for the dash A/C in a '99 36'? How about an '01 38'? I am charging my dad's 36 now and am looking for a starting point.

Thanks.

ernieh · 11-19-2009, 11:03 AM

A good starting point might be what kind of MH.

Just a thought.

Riverside · 11-19-2009, 11:07 AM

Alpine is the coach brand.

justimagination · 11-20-2009, 01:36 AM

Look on the evaperator housing under the hood on the passenger side. There should be a placard (sticker) with the amount of freon. Not knowing what engine you have, I would start with somewhere around 38 ounces, don't overcharge it, and go from there. I would slide temp lever all to coldest setting, put the fan speed on low, and let it run a bit. Put a temperature in the center outlet, 40 degrees is great, and you can get that even with 134 freon. Good Luck.
David G.

TXiceman · 11-20-2009, 07:14 AM

You really need to get some help now and get a set of gauges so that you can check the pressures. The fan should be set on high speed, not low to charge the system.

I do not weigh the charge in, but charge using a set of gauges, checking the air out temperature and felling for the liquid level in the condenser and liquid line.

If you are not familiar with handling refrigerant properly, it can be very dangerous.

Ken

Old Scout · 11-20-2009, 08:00 AM

I agree with TXiceman, replacing/filling the 134a on our coaches is not a straight-forward process. I called Acme [they built the Alpine dash A/C components] and they told me it was a 5 lb system--wrong--more like three or four. Anyway, you need to use guages, know the desired high/low side pressures for the ambient temp, know how much compressor oil is already in the system, draw a full vacuum [30 minutes] if the system has been opened or leaked. And if that isnt enough, older Alpines have an issue with the hydraulic engine fan--it doesnt always engage/run fast enough at engine idle to sufficiently cool the A/C radiator[false guage readings]. Finally, good luck getting the cooling temps to 40 degrees--mid 50s if you are luck. So are you sure you really want to do this yourself??????

justimagination · 11-20-2009, 07:26 PM

TXIceman & Ole Scout, I was assuming he has the ability to use a set of gauges to put freon in a system. His original question was how much freon, that's all I was trying to answer. That being said, not knowing what system he has, @ 38 ounce recomendation, that is a good starting point, as too much freon will not cool properly. If you running 134 and you can't get 42-44 degrees with good air flow(55 mph), your system is not correctly charged. My 12 year old motorhome will do it with the original freon charge from the factory, of course it's a Ford, which just turned 40K mles. Ford has always had a good system, whether in a motorhome, truck, or passenger car.
My suggestion for high cool temperature and low blower speed was meant for checking the temperature "AFTER CHARGING", and in no way was it meant for charging the system. JMHO people, just trying to help. Good Luck,
David G.

Riverside · 11-20-2009, 10:31 PM

Thanks David. You are exactly correct. I have all the correct equipment as well as quite a bit of experience with R-134 systems in your every day auto as I own a collision repair shop. I was just looking to get a starting point to charge my dad's coach with it completely empty. I scaled it when we ran it down but I didn't trust it was charged correctly to begin with so I wanted to start with the correct amount. At this point it blows cold and the pressures are pretty good so all is well.
Also I appolgize for not initially posting my coach brand and have since put it in my signature. Being new, I guessed that since I posted in the Alpine forum I either own or was discussing an Alpine. Please don't hate the newbie!

Thanks.

Michael

"007" · 11-20-2009, 11:25 PM

Nobody hates a newbie Riverside its always easier to post a question its just all the small stuff that gets people confused.

Welcome to irv2 enjoy the forums and do post often.

justimagination · 11-21-2009, 12:09 AM

Thanks Michael, glad I could be of help. A/C systems are very peculiar, too much or not enough and it just won't do it's job.
David G.

Old Scout · 11-21-2009, 09:42 AM

I am sorry if I hurt anyone's feelings--that was not my intent. Perhaps my own frustrations with the dash A/C on my 03 Alpine were creeping into the conversation. My point on capacities were two-fold: 1-the Acme tech [company now defunct] seeemed to be aware of the Alpine system and told me it was a 5lbs system. Based on my experience, its more like 3-4 lbs; and 2-unless you can evacuate the entire system and start from scratch, eg, oil, 134, dryer, etc., it seems to me that capacity is kind of a guess anyway. Not sure what model year Alpine you are working on but despite numerous hours on my own and quite a few $$$$s to other, so called profssionals, the dash A/c performance on our 03 is only adequate.