Posted by Jon Hagen on April 24, 2009 at 18:16:59 from (12.175.230.58):
In Reply to: Air conditioning help posted by Bill in IL on April 24, 2009 at 12:51:11:
Before you do anything, you need to get a gauge set on there to see what the low / high pressures are.
If this is on a R12 to R134a conversion, The 80 % rule that works fairly well on automotive systems, will almost certainly get you overcharged on an AG application.
I have found that charging a converted system is best done by vent temp alone. add enough R134a to get the system working, them add more, a few ounces at a time until adding a bit more (2 oz) does not produce a further drop in vent temp. This is the "sweet spot" that will give maximum cooling with minimum high side pressure. Adding more refrigerant beyond this point will actually reduce cooling and the high side pressure gets nuts real fast. I have done many of these conversions, and find this charging procedure produces the best results.
I hope your unit is just overcharged, as many compressors with reed valves like the old inline York pumps will see exhaust valve damage if slugged with liquid refrigerant during charging. If an exhaust valve is damaged, the cylinders will fill with liquid refrigerant that backfed from the condenser. Restarting a compressor with a damaged exhaust reed valve will take so much torque to push the liquid refrigerant out that if usually smokes the clutch or drive belt. Its tough to throttle liquid refrigerant into the low side of those systems, so I will only charge them using vapor. If your filling it with the 12 oz cans, it helps to set the can in a container of warm water to "boil off" the liquid to vapor. I use only Ester compressor oil in a converted system, as it will tolerate a bit of mineral oil still in the system, where PAG will not.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Old Time Threshing - by Anthony West. A lovely harvest evening late September 1947, I was a school boy, like all school boys I loved harvest time. The golden corn ripens well and early, the stoking, stacking,.... the drawing in with the tractors and trailers and a few buck rakes thrown in, and possibly a heavy horse. It would be a great day for the collies and the terrier dogs, rats and mice would be at the bottom of the stacks so the dogs, would have a busy time hunting and killing, all the corn was gathered and ricked in what we c
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
