Our GV is a 1989 model. Did it originally come with R-134? What year was R-134 the change made from the old Freon? I found records from a PO where the system was charged with R-134. I looked at the compressor and it is a Harrison and the nameplate has a tag with R-22 on it.
One of the receipts for the service of the dash cooling system shows X amount of R-134 and around $100 for labor to service the system. Wouldn't a unit converted from the old Freon to R-134 have a tag or something to indicate the conversion? The condenser unit up front has two large electric fans mounted on the front of the unit controlled by two switches on the dash.
Has any other 1989 owner any information as to which refrigerant they have?
FWIW, our 88 had R-12. We changed it out (134a) in the year we purchased the coach, think it was 03. Seals in compressor were dry recharge worked for 2 years then replacements. ^.^d
You might look at the charging ports. Their is a size difference where the hoses connect. Older units can have the adapters screwed on, and the 134a ports will have larger diameters.
R-12 manufacture was banned in the United States along with many other countries in 1994. R-134a was implemented as it's replacement in the early 1990s. You cannot add one to the other because, like Dave says, the ports are a different size.
Ports for R-12 are threaded and look like a tire stem but only larger. R-134 ports are quick connects (like an air chuck) with one being larger than the other. They maybe color coded with one being blue and the other red. The ports are located just above the condenser fan on the forward bulkhead. My condenser fans come on automatically with the compressor clutch - there is no switch on the dash. I don't think your dash switches are OEM.
Edit: Keep forgetting Nitehawk's coach is an Oshkosh chassis. So don't know where the charge ports might be.
Our 88 ports were under the front cowlling near the coil. ^.^d
Correct quick connect
Now, having some idea what to look for, I found the following: opening the small access panel up front on the passenger side I found "stuff".
There is a chrome thingamabob with copper tubing coming out the end (just found it is the expansion valve). Maybe a diaphragm of some sort? It is about the size of a silver dollar (remember those? size before deflation?). Under the copper tubing that comes out the center of the disc is a blue label, upside down, that reads R-134A.
Over on the "firewall" where the hoses are fastened to the wall there is a tee fitting with a red plastic cap screwed onto the tee fitting. It has a hex on the top end, obviously for a wrench. Do I dare remove this cap to ascertain whether there is a connection under it? This is the only "fitting" up front. Is it the low or high pressure hose? How do I find out?
Whatever you do, wear gloves!
The coil is that enclosure on the navigator side. The low and the high doesln't matfer-perse' because the DYI stuff you can't hook it up wrong. ^.^d
blue low, red high
The red cap is for the high side and yes it can be removed, and you will find the r134 port there. There should also be another port fairly close that might have a blue cap. The caps can be removed as there is a shrader valve in the fitting to keep in the refrigerant
Thanks Ron, and everyone. I can see the red capped fitting, but have not located the other/blue fitting. Is it on the other hose?
Might be back at the compressor also. R134a began phasing in about 1992. Take a look at your towed to see what the caps look like. They may be red & blue, but if they're OEM they might be black or brown or maroon or light green... The shapes are strikingly similar between manufacturers. In the picture the group of 4 is high side caps (Reds a little taller because on retrofit fittings) and the group of 3 are low side caps (blue on retrofit fitting). When I was a tech, I didn't worry about the color of the fitting. If I dropped one, I got a spare out of my junk drawer and theirs went in the drawer when I swept up. Never play connect the color! Techs will change colors on you to meet functionality parameters. I learned that the hard way.
Having red and blue caps on the a/c lines does not necessarily mean that they are R134. Our '93 U225 is R12 but I have done a conversion on the caps to allow me to use our a/c manifold to recharge... with R12. When we moved here 20 years ago I lost my old gauges and manifold so bought a new one from Harbor Freight but since it only fit R134 valves I had to install the little converters. I suspect that a lot of coaches have had that done.
I think that if I didn't know - for sure - the refrigerant then I would check to see if there is any notice around the compressor area to indicate that it had been converted.
I've heard various stories about whether it's ok to put R134 into an older system that was designed for R12 but at the very least I would put a vacuum pump on it and suck it down to nada before adding R134.
Craig
Craig, like I said in an earlier post--I found a label under the copper tube that comes out of the expansion valve that says R-134A. Also, I have found two references/receipts in the PO receipts and records indicating recharged with R-134A. I do intend to look under the red cap and look for the low pressure connection also today.
I just wanted to make sure the coach uses R-134A. With the help of members on Foreforums I am now confident I have the R-134A upgrade as of 2009.
Thanks everyone. Now I only need to find out what # the system requires.
I would consider just going to Wally world or an auto parts place and getting one of those cans of freon with the hose and adapter on it. Usually has a little guage that shows green red and yellow. You can top off your AC with freon doing this. I have done it and worked well for some time now. It was easy, quick, and pretty inexpensive to restore my dash AC cooling. Probably took about 30 mins and 30 dollars. If you have a major issue (besides small leak) then probably won't last long or even restore cooling. But if you only have a small leak, got her done (at least for a while)! Best!
X 2 what Charles said ^.^d
They also have a seal treatment.
Oh! Neglected to say that I agree with John, WEAR GLOVES if you decide to add a little freon to recharge your AC. That dang stuff is COLD! LOL, I also wear glasses, but if for some reason you don't, this would be a good time to wear some for safety.
The blue cap should be on the other line which might be larger in diameter. Also make sue to only add through the low side fitting, not the red high side fitting as that might cause the can to explode. Be careful.
There are some really good A/C servicing videos on YouTube that explain a lot of the issues. This guy seems to have a lot of videos out there. scotty kilmer - YouTube (https://www.youtube.com/results?search_query=scotty+kilmer)
Recover & evacuate through hi & lo ports. Always charge on the low side. Put your dye in first & use your refrigerant charge to wash it into the system. Can upright to charge with vapor. Don't try charging with liquid if you don't know how. Hydrolock your AC comp if you do it wrong. system turned off, pressures should be about/slightly above ambient temp. System on, steadily engaged AC clutch lo side about 25-30 psi steady. hi side will vary greatly depending on ambient temp, heat load, RPM & other variables. 150+ psi up to 400 which is when I start to cringe & look for an exit. 150-250 normal, higher could be heat load. Over 300 high side psi something's wrong with system or test procedure. Its easy to overcharge a system. Not so easy replacing burst hoses. Be careful! I'm a big believer in UV dye. It can make leak detection fairly easy.
Well, so far "no joy in Mudville", as I could not find another fitting back by the compressor or up front. I started to take off the sheet metal cover on the Atwood housing this morning but had to quit as our oldest great grandson "graduated" from kindergarten today and the DW and I had to be there for the big occasion. Then this evening was his T-ball game. Hada be there!!
Question: The fitting I described earlier--the one with the red cap-- is mounted between two sections of hose and the hose ends are clamped on with radiator hose clamps. Sure doesn't seem like this would be high pressure. The other hose looks quite strong as the fittings on the ends are crimped on. Am I looking at the low pressure side when looking at this red capped fitting??
I don't know. Post a picture. Does it look like the one in the picture I posted?
Agree with Brad, here is one youtube video that really should be helpful with regard to what to look for for the low pressure side and also how to add freon. This is by a company that sells a product. It seems to be spot on.
Charles
How to Recharge Your Car AC with Arctic Freeze - YouTube (https://www.youtube.com/watch?v=-p2WzuoSHHA)
The low side fitting on your coach should be up front somewhere in the area of the other fitting that you found. That hose will be the larger hose coming out of the evaporator