York compressor swap/oil replace question

Stevehose

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I've pretty much determined my new a/c upgrade setup, keeping r-12:

Sanden 709 compressor
new drier
16x20 parallel flow condensor
york-sanden bracket
custom fit hoses (prob not red ones due to expense and availability)

nuke the vibration damper canister

The compressor comes filled with r-12 oil, do I have to drain any to compensate for oil in the evaporator portion already or is it insignificant? If I need to compensate, how much should I take out or how should I estimate the difference? Any issues with my chosen rig? Am tired of my York dropping the rpms and sounding like a cement mixer when kicking on.
 

sfdon

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I run every compressor with carquest oil that works with both r12 and 134a
costs more but leaves your options open.
 

61porsche

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No more oil. That compressor and oil is compatible with what you have.

If you ever had to change the oil- the nameplate tells you how much. Not ever likely though.

As long as your system was working fine before and you're not changing to 134a, then no; there's nothing more to do. If it wasn't , I'd say change the expansion valve and filter. The story goes that the temperature switch on the later models had a sticker on an adjustment screw in the back.

The compressor and crossflow condensor will be much more efficient. Sandens had a low pressure switch on the rear- look for it. haven't seen the new ones yet.

When filling watch your discharge air temp. The last 6oz of refrigerant will cause a rapid decrease so shoot for 40 degrees slowly. I assume you're using guages as well. You need to find a temperature/ pressure chart.

Here's some tips- http://www.aircondition.com/tech/questions/82/ to help in the understanding of the relatonship of ambient to pressure readings.

Keep the original bracket and compressor for someone else- I know John Heine is looking. That's all he needed. Maybe pm him. Might be able to offset some of the costs.

Good luck and call if you get stuck.:) Piece of cake compared to stabing that 4 speed while on your back.
 

61porsche

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Believe it or not- they still make the stuff- in Alabama. If you have the license- you can get 50lb jugs and cases of cans delivered to your door!:)
 

Stevehose

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Ok thanks for the oil info.

The bracket - I am using one that attaches to the existing York swing bracket that the Sanden mounts to so I am keeping the bracket at this point. John can have my York so I will PM him - it still works.

Gauges for sure - new set on the way.

Thanks for the tips I've got your number :mrgreen: and am not in any hurry to do anything to the drive train for a long time!

No more oil. That compressor and oil is compatible with what you have.

If you ever had to change the oil- the nameplate tells you how much. Not ever likely though.

As long as your system was working fine before and you're not changing to 134a, then no; there's nothing more to do. If it wasn't , I'd say change the expansion valve and filter. The story goes that the temperature switch on the later models had a sticker on an adjustment screw in the back.

The compressor and crossflow condensor will be much more efficient. Sandens had a low pressure switch on the rear- look for it. haven't seen the new ones yet.

When filling watch your discharge air temp. The last 6oz of refrigerant will cause a rapid decrease so shoot for 40 degrees slowly. I assume you're using guages as well. You need to find a temperature/ pressure chart.

Here's some tips- http://www.aircondition.com/tech/questions/82/ to help in the understanding of the relatonship of ambient to pressure readings.

Keep the original bracket and compressor for someone else- I know John Heine is looking. That's all he needed. Maybe pm him. Might be able to offset some of the costs.

Good luck and call if you get stuck.:) Piece of cake compared to stabing that 4 speed while on your back.
 

hans3

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As you know, the system vacuum pull will not necessarily reveal small leaks. Leak detectors are $$$ and tough to locate for rentals. After charging, spray all connections with sopay water or simple green, etc, to identify these small leaks.
 

thehackmechanic

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If you know you're sticking with R12 (a fine choice, IMHO), the best compressor oil is tried-and-true mineral oil. If your new compressor comes filled, that's almost certainly what it comes filled with.

To answer your question about whether you need to take oil out, oil tends to get distributed throughout an a/c system, with portions of it residing in the compressor, condenser, evaporator, and receiver. If the system takes, for example, 8oz of oil, you can estimate rule of thumb 2oz in each of these four components. The ONLY way to be 100% certain how much oil is left -- and thus how much to add -- is to flush the entire system. Because there's not an a/c oil dipstick, over time a/c systems either have too little oil in them or too much (many mechanics routinely add 2oz of oil whenever the system is serviced). But if you're replacing the compressor, condenser, and receiver, all that's left is the evaporator; You could take 1/4 of the oil out of the compressor, but I wouldn't worry about it too much. I'd just leave it be, but I'd remember that you could be slightly on the high side.

If you're rejuvenating a long-dead system, you should flush the system anyway, which flushes out any crap along with whatever oil is left. Flushing is achieved with a canister that you fill with a/c flush or mineral spirits, and pressurize with your compressor. Sounds like you're replacing the condenser, so flushing that part is not necessary. Ideally you should flush the condenser, evaporator, and every hose. You should never flush a compressor; you should just fill and drain it a few times. And the dryer should just be replaced. Actually you can't flush through the evaporator because the expansion valve is in the way, but you can pop-flush (hold the flush canister on the evaporator input, then on the output, and have it build up pressure until it pops off, then use the same pop-off technique with compressed air).

All that having been said, there is risk in flushing because there is risk in taking off hose connections that haven't been disassembled in 35 years. If a car has been sitting with the a/c open (ie, no compressor, hoses hanging), or if the compressor has seized and may have thrown metal into the system, you do need to flush, but if you're, say, replacing a leaky condenser, you can risk going without the flush.

Back to the oil... Last year I bought a '93 Toyota Land Cruiser with non-functional a/c. I flushed every line. I leak-tested it (I use pressurized nitrogen) and found a leaky condenser and replaced it. Then I leak-tested it again and found a leaky evaporator core and replaced it. The old core was wet with oil. I leak-tested the system a third time and it held. I was about to evacuate it and charge it up when I thought... gee, with that core wet with oil. I wonder how much is left? The only way to know was to pull the compressor and turn it upside down. I'm normally not a do-it-once-do-it-right guy, but I sighed and pulled the compressor. It was bone-dry. No oil at all. Had I not done this I would've cooked the system.
 

Stevehose

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Thanks for this, my a/c works now but I don't like it when the York kicks on - it ruins my driving experience :). I am keeping r-12 and replacing everything except the evaporator and installing the most efficient components at reasonable cost. The sanden 709 compressor is 7 pistons instead of the 5 on the 507 which should give it a smoother rotation and more output, especially at low rpm. The parallel flow condenser should help. So the weak link efficiency-wise will be the evaporator but not much can be done there and I don't want to take it out right now and start that bloody mess.

I took the radiator out last night and it's headed to the shop today for a re-core. "May as well do that while I am in there" :mrgreen:


If you know you're sticking with R12 (a fine choice, IMHO), the best compressor oil is tried-and-true mineral oil. If your new compressor comes filled, that's almost certainly what it comes filled with.

To answer your question about whether you need to take oil out, oil tends to get distributed throughout an a/c system, with portions of it residing in the compressor, condenser, evaporator, and receiver. If the system takes, for example, 8oz of oil, you can estimate rule of thumb 2oz in each of these four components. The ONLY way to be 100% certain how much oil is left -- and thus how much to add -- is to flush the entire system. Because there's not an a/c oil dipstick, over time a/c systems either have too little oil in them or too much (many mechanics routinely add 2oz of oil whenever the system is serviced). But if you're replacing the compressor, condenser, and receiver, all that's left is the evaporator; You could take 1/4 of the oil out of the compressor, but I wouldn't worry about it too much. I'd just leave it be, but I'd remember that you could be slightly on the high side.

If you're rejuvenating a long-dead system, you should flush the system anyway, which flushes out any crap along with whatever oil is left. Flushing is achieved with a canister that you fill with a/c flush or mineral spirits, and pressurize with your compressor. Sounds like you're replacing the condenser, so flushing that part is not necessary. Ideally you should flush the condenser, evaporator, and every hose. You should never flush a compressor; you should just fill and drain it a few times. And the dryer should just be replaced. Actually you can't flush through the evaporator because the expansion valve is in the way, but you can pop-flush (hold the flush canister on the evaporator input, then on the output, and have it build up pressure until it pops off, then use the same pop-off technique with compressed air).

All that having been said, there is risk in flushing because there is risk in taking off hose connections that haven't been disassembled in 35 years. If a car has been sitting with the a/c open (ie, no compressor, hoses hanging), or if the compressor has seized and may have thrown metal into the system, you do need to flush, but if you're, say, replacing a leaky condenser, you can risk going without the flush.

Back to the oil... Last year I bought a '93 Toyota Land Cruiser with non-functional a/c. I flushed every line. I leak-tested it (I use pressurized nitrogen) and found a leaky condenser and replaced it. Then I leak-tested it again and found a leaky evaporator core and replaced it. The old core was wet with oil. I leak-tested the system a third time and it held. I was about to evacuate it and charge it up when I thought... gee, with that core wet with oil. I wonder how much is left? The only way to know was to pull the compressor and turn it upside down. I'm normally not a do-it-once-do-it-right guy, but I sighed and pulled the compressor. It was bone-dry. No oil at all. Had I not done this I would've cooked the system.
 
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