Ok, another A/C query.
We just finish a total restoration of our 1970 2800CS. As part of that we upgraded the A/C system with parallel flow condenser, @Blinkling upgraded evaporator, and a new Sanden 508 compressor, and R134a. We chased a number of leaks until we finally got it (we believe) leak tight.
Recently we took a long drive in hot sweaty SW Florida to see how the system is working. See all of my posts on the A/C system and more recently the vapor lock issue thread.
Anyhow it seems that when the compressor is on, it really loads down the engine more than I think it should, which most likely contributed to the vapor lock issue, which we never experience before here in SW FL. we have a Porsche 914 with A/C, and the compressor does not load the engine down as much as the 2800CS with half the HP.
During the installation chasing leaks we had evacuated the system numerous times and during the process we think we sucked out a lot of the pag oil in the new compressor. Once leak tight we charged the system with 2-12 oz cans of 134a. We stopped with the end of the 2nd can as the suction line was just starting to sweat, an indicator that the charge is nearing the correct amount.
We have an engine sticker and factory data says the correct R12 charge should be 2.81lbs or about 45oz. A general rule of thumb is r134a charge is .75 times the R12, in this case almost 34 oz of 134a. We only put in 24oz.
To verify the total charge in the system, we just recovered the refrigerant and got just shy of 23oz.
So we are asking, are we low on the 134a charge, which could make the compressor load increase?
Also we did check the oil amount by using these
and only got a little indication, mostly yellow dye we think, so we do believe we are low on oil which could also load down the engine if the compressor is working hard. Admittedly these things are not very accurate.
So, A/C gurus, what amount of 134a in oz is a target charge. Am I really low on charge???
We plan on adding some pag oil and recharge the system to how many oz??????
Thanks
jjs2800cs
We just finish a total restoration of our 1970 2800CS. As part of that we upgraded the A/C system with parallel flow condenser, @Blinkling upgraded evaporator, and a new Sanden 508 compressor, and R134a. We chased a number of leaks until we finally got it (we believe) leak tight.
Recently we took a long drive in hot sweaty SW Florida to see how the system is working. See all of my posts on the A/C system and more recently the vapor lock issue thread.
Anyhow it seems that when the compressor is on, it really loads down the engine more than I think it should, which most likely contributed to the vapor lock issue, which we never experience before here in SW FL. we have a Porsche 914 with A/C, and the compressor does not load the engine down as much as the 2800CS with half the HP.
During the installation chasing leaks we had evacuated the system numerous times and during the process we think we sucked out a lot of the pag oil in the new compressor. Once leak tight we charged the system with 2-12 oz cans of 134a. We stopped with the end of the 2nd can as the suction line was just starting to sweat, an indicator that the charge is nearing the correct amount.
We have an engine sticker and factory data says the correct R12 charge should be 2.81lbs or about 45oz. A general rule of thumb is r134a charge is .75 times the R12, in this case almost 34 oz of 134a. We only put in 24oz.
To verify the total charge in the system, we just recovered the refrigerant and got just shy of 23oz.
So we are asking, are we low on the 134a charge, which could make the compressor load increase?
Also we did check the oil amount by using these
Enviro-Safe Pittstop R134a Oil Checker Analyzer Tester 10 pack #5030 816024002902| eBay
Part#: 5030. Many A/C compressor failures are caused by low oil levels and dirty contaminated oil in the A/C system. A cost effective and easy way to detect air conditioning oil levels and harmful acids in the oil of A/C systems without changing out the A/C system and draining all the oil from...
www.ebay.com
and only got a little indication, mostly yellow dye we think, so we do believe we are low on oil which could also load down the engine if the compressor is working hard. Admittedly these things are not very accurate.
So, A/C gurus, what amount of 134a in oz is a target charge. Am I really low on charge???
We plan on adding some pag oil and recharge the system to how many oz??????
Thanks
jjs2800cs
