Well I changed my freon to 134 with a kit. The kit had the low side fitting and I put that on. My question is on the high side. Is the high side that small fitting that is up by the compressor and is on the black bottle by the compressor ??? If so what fitting size do I need as my kit did not have one ???
David, Low side line is the larger line while the high pressure side is the smaller diameter line. Not knowing what lines may have been changed this is a general rule to follow. George has some good information on his site http://www.buickperformance.com/ac.htm Hope this helps.
Sorry that didn't help, it didn't tell me what I needed to know. I know that the Low Side, (the hose that you need for the recharge kits cheap fill hoses) is the hose that runs between the evaporator and the compressor. The evaporator is most times up close to the firewall (sometimes under the dash) and that the High Side is out by the radiator and will be by the condenser and the dryer. What I don't remember (it's been a long time since I've worked on AC systems) is what is the High Side fitting on this system. As I said I think it is the fitting that is on that black bottle looking part (I can't remember if that is the dryer in this system or not) that is mounted just above the compressor. i think it is as I can not find any other fitting that would be the High Side fitting. I want to get the correct fitting for it, as I have added the Low Side fitting and changed it over to R-134a now, I want the correct fitting on the High Side so I can hook up the newer R134a Gauges to do the system correctly if I want to do a vaccum draw or any other of the services that a AC system needs. I know that NAPA has a small kit https://www.napaonline.com/Catalog/CatalogItemDetail.aspx?A=BK_7653144_0312341275&An=0 but I don't think the fitting I need is in that kit. Thanks Though.
I think I have found what I need, it's a 3/16" threaded converting adapter from NAPA. the straight one https://www.napaonline.com/Catalog/CatalogItemDetail.aspx?A=TEM409902_0249719835&An=0 will work, or I could go with the 90 0/0 one https://www.napaonline.com/Catalog/CatalogItemDetail.aspx?A=TEM409908_0215040068&An=0 Sorry I have to give you those links to NAPA, I can't give you the ones I get off of my dealer side of NAPA (it shows more info) but I have tryed to post those links and they won't allow them to open unless you are signed in. Any AC guys out here, am I on the correct path now :Brow:
The high side on r12 is a smaller fitting. after you convert it the high side will be the larger fitting. on my 350 the low side is on the poa valve ontop of the evap box and the high side is on the back of the compressor:3gears: From the pic you posted the high side is on the big black accumulator
Great, Thank You. I thought it was that fitting, as I said I couldn't find any other HS fitting so I thought it had to be that one. I'm going to check it out tomorrow and see what one it is (3/16" or 1/4") and order it up from NAPA. Thanks Again
Your original High side fitting will be 1/4". The smaller 3/15" HS fitting didn't come into use until the late 70s. Your NAPA store should have adapter fittings available in steel. The cheap aluminum fittings are very prone to leak. If the Low side fitting in the kit was aluminum, you should consider replacing it with a steel one.
I have the 3/16" one, I checked it today, it's the 3/8" X 24 thread. I ordered up one of the regular ones and one of the 90 degree ones. That way I can decide which one to use, that black can is up high and if I put the straight one on I'm worrying about clearence trouble, I won't know till I get it though. I would rather run the straight one if I can, it will be less chance of leakage with the straight one then the 90 degree one with it's extra parts to it. I'm going to grap some of the red and blue caps also as my retro kit only had black caps. The Low Side one from the kit was aluminum, so I will grap a steel one tomorrow while I'm there getting the other ones, thanks. :TU:
The "black bottle part" above the compressor is a muffler. I believe on your vintage Buick, the receiver/dryer is just inboard of the radiator core support, or on the inner fender. The viewing window is on top, and if you are really lucky, still has the the plastic dust cap covering the window. Do not rely on this for gauging TC134A performance, by watching for bubbles, as you would for R-12. Also, you do not need the high side fitting to evacuate the system, only to gauge high side pressure. Whatever you do, don't charge through the high side valve. But you knew that, right? Nice clean lookin' underhood, BTW.
On that note, I hope you changed the receiver/dryer.The TC134A system uses a different desiccant, I believe. Did you flush all the old oil out of the system when you refilled the compressor with the TC134A-compatible oil?
Yes I know not to fill from the High Side, but thanks. Things tend to go wrong if you try to fill from the High Side, like big bangs and booms and people get hurt, so yes never fill from the High Side !!! So far the "black bottle" is the only other fitting I have found besides the Low Side fitting, I'll look again to see if it hidding were you say, but, I haven't seen it there yet, but I will check again. Well yes and no :Brow: , the AC wasn't working and it wasn't showing anything on the gauge. I wanted to find out if the system would work or not so I just put the Low Side fitting on and filled it. :Brow: Now that I know the system works and I'm getting the correct High Side fitting I will change things like receiver/dryer and what ever else needs to be done. I didn't want to throw a bunch of money at it at 1st, the kit didn't cost me much with my discount that I get at NAPA. So I figured if a kit with 3 cans of 134a (with the oil and everything else needed in those cans) would bring the AC back to life I would then do it correctly and do the flush and all. I couldn't see dropping a bunch of money into it to find the compressor or the condensor or something else wrong. If there was something else wrong that was going to run me a bunch of money to fix I was going to take everything off and get one of the cover plates that is just for the heater and not have AC. Now that I see that it works I will do it correctly now and get everything set up for the 134a. I'll do the receiver/dryer now and I'll flush the system now that I know I don't have to spend a million dollars to fix anything. Thanks
Its interesting that your HS port is 3/16". I wonder if that is a replacement line set made some time after the different fitting sizes were mandated? When you do the full service on the system, don't forget that your A6 compressor has an oil sump. You drain, oil flush and fill the crankcase via the drain plug. You add the entire oil amount to the compressor, not into the lines like on later systems. The port on the muffler is the HS service port. I recall that being a "Buick thing" back in the day. I'm pretty sure that none of the GM other manufacturers placed it there. NAPA will have a 90 degree retrofit adapter for that. On the steel retrofit fittings, remove the old valve cores. The new fittings have the scharder valves in them.
