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 - A Lifetime of David Brown Tractors - by Samuel Kennedy. I was born in 1950 and reared on my family�s 100 acre farm. It was a fairly typical Northern Ireland farm where the main enterprise was dairying but some pigs, poultry and sheep were also kept. Potatoes were grown for sale and oats were grown to be used for cattle and horse feeding. Up to about 1958 the dairy cows were fed hay with some turnips and after that grass silage was the main winter feed. That same year was the last in which flax was grown on the farm. Flax provided the fibre which w
... [Read Article]
Latest Ad:
For sale Farmall super A tractor is complete and has just been setting for awhile,it was running when pulled out of the barn,shouldn’t take to much to get it going asking 1100.00
[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.
