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Oil Distribution before vacuuming, 1997 VW Golf Cabrio?

bearing01 on Sun May 11, 2008 12:29 PM User is offline

Year: 1997
Make: vw
Model: cabrio
Engine Size: 2.0L
Refrigerant Type: R134a
Country of Origin: United States

Sanden SD7V16 compressor.
Total System takes 3.9oz of SP-10 (PAG-46)

Hey all,

Quick question regarding where to put the oil before I button up the system. I just flicked through the Bentley service manual to see the oil distribution chart. They list a distribution of: 1.9oz in compressor, 0.4oz in condenser, 0.8oz in evap, 0.4oz in drier and 0.4oz in low side hose.

In also states that OEM dealer compressors come filled with 3.9oz, which is the total system capacity for oil. In a later section, giving the recipe for flushing, it states to drain the compressor's oil and to refill the compressor with the total amount of oil.

Seems odd to be told to dump all the oil in the compressor. Should I follow these instructions or should I distribute it around as per above?


mk378 on Sun May 11, 2008 1:46 PM User is offline

It works fine to put it all in the compressor. The amounts for each component are in case you are just replacing one component and need to replace the oil it contained.

Edited: Sun May 11, 2008 at 1:48 PM by mk378

iceman2555 on Sun May 11, 2008 2:45 PM User is offlineView users profile

Adding to much lubricant to a compressor maybe as harmful as having too little.
Also, are you completely sure there is the correct amount of lubricant in the compressor? And are you absolutely sure of the quality? There is one method...drain, measure and refill with the correct amount and a quality that meets your satisfaction.
Two oz is normally sufficient for a scroll or rotary vane compressor.....excessive amounts may result in possible damage.

The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

bearing01 on Sun May 11, 2008 5:44 PM User is offline

I'm 100% sure the specified volume of oil for the entire system is 3.9oz (115mL)

I don't think the new SD7V16 compressor I got from ACkits has any oil in it. It's just the compressor from the dealer has prefilled oil, as suggested in the Bentley manual. I will be draining any/all of the oil out of the compressor before filling it.

From what I know it's always good practice to turn the compressor's crankshaft 10 times or more to pump excess oil out.

Right now I have the compressor drained, drilled a hole in the drier and nothing drained out of that, blew air through the hoses and I got around 30mL so far. I got the condenser left to blow air through but at the rate I'm going to say that I don't know where the other 80mL of oil is. The system didn't have a leak so I don't think I lost it that way.

I think I'm going to put most of the oil in the compressor, as per the manual, and then put the rest in the evaporator. Turn the compressor's crankshaft 10 turns or more to hopefully pump out the excess oil.

bearing01 on Mon May 12, 2008 10:24 AM User is offline

I finished the job and she now blows 10'C vent temp on max blower speed and around 8'C on low speed. I'm fine with that for now. It was only around 65'F outside so I couldn't do a good performance test.. Looks like I got ballpark 30'F temp drop from condenser inlet to outlet. I didn't measure the evap super heat, but both high side lines in/out of the drier appear to be the same temperature corresponding to high side pressure. On the next hot weekend I'll have to redo the performance test.

The Sanden SD7V16 from ACkits did come filled with the full 115mL system oil capacity. I guess I could have just left the oil in there but I had a new bottle of double-end-capped Pag46 with UV that I knew had no moisture in it. I dumped the oil out of the compressor and put around 72mL of new oil in the compressor, around 20mL in the evaporator and the rest in the condenser and drier. I then turned the compressor's crankshaft snout 10 times with a wrench to hopefully avoid any possible hydro-lock. Then I pulled a deep vacuum for 90 minutes considering 70'F ambient temperature.

Another note. The SD7V16 has two thin O-rings on the inlet/outlet ports that didn't have a match in the European o-ring kit supplied by ACkits. There certainly is a ton of O-rings in that kit, but none had a thickness that matched the compressor ports. I reluctantly reused the O-rings off the old compressor because they looked in good shape and I feared that if I used ones that were too thick the high one could blow out.

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