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Priming compressor

LincolnF on Tue July 23, 2013 9:36 PM User is offline

Year: 1999
Make: Ford
Model: Escort
Engine Size: 2.0
Refrigerant Type: R134a

Is the purpose of priming a compressor to remove the oil or is it to get the oil in position to lubricate the compressor?

Reason I ask:
Replaced the low pressure hose from accumulator, accumulator, FS-10 compressor (new came with oil or so said the instruction sheet), and orifice tube. Connected everything, oiled o-rings, made sure the spring locks are connected.

I left off the low pressure hose from compressor to condenser (I guess technically at this time it's high pressure). The hose is long enough and flexible enough that I have the opening (condenser side fitting) literally above the radiator.

As I turn the compressor clutch clockwise by hand I eventually heard some gurgling, then eventually a load of oil spits out.

Should I connect the system "completely" then prime the compressor? Should there be oil spitting out the hose? If I do connect the system completely, will it take a year of lifting at Gold's Gym to be able to turn (and hence compress the air) the compressor clutch?

Sorry for the long post.

iceman2555 on Tue July 23, 2013 9:45 PM User is offlineView users profile

This issue about 'priming' or clearing lubricant from the piston bores has always been fascinating. A compressor at rest has both the suction and discharge reeds closed. There fore there should be not lubricant in the piston compression areas. Back side of pistons, yes....for sure.
The issue you are experiencing is the result of compressor rotation produces both suction and discharge pressures....and thus the lubricant being expelled from the unit. We always drained and refilled compressor with the correct type and amount of lubricant....never trusted the labels....never...never...never.
Why not try mounting the compressor and install the manifold. Rotate the compressor all you like...the lubricant stays within the system.
A side note: Compressors delivered to the OE assembly line are shipped with a full system lubricant charge and never rotated until start up. Also they are shipped with the clutches 'burnished' and ready to operate.
Good luck with your repair.

-------------------------
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

LincolnF on Tue July 23, 2013 9:56 PM User is offline

Thank you sir. I may do that -- remove the compressor, drain and measure oil according the Ford factory manual, replace with amount Ford says, and go from there. Remount, button up whole system and prime away.

My biggest worry was/is how difficult is it to prime the compressor by hand with whole system closed (obviously air filled)?

wptski on Wed July 24, 2013 8:03 AM User is offline

Quote
Originally posted by: iceman2555
This issue about 'priming' or clearing lubricant from the piston bores has always been fascinating. A compressor at rest has both the suction and discharge reeds closed. There fore there should be not lubricant in the piston compression areas. Back side of pistons, yes....for sure.

The issue you are experiencing is the result of compressor rotation produces both suction and discharge pressures....and thus the lubricant being expelled from the unit. We always drained and refilled compressor with the correct type and amount of lubricant....never trusted the labels....never...never...never.

Why not try mounting the compressor and install the manifold. Rotate the compressor all you like...the lubricant stays within the system.

A side note: Compressors delivered to the OE assembly line are shipped with a full system lubricant charge and never rotated until start up. Also they are shipped with the clutches 'burnished' and ready to operate.

Good luck with your repair.
Don't know how many times I've read here to add oil to the compressor then rotate a few times then install. I've also read one of your posts which stated to put about half the oil in the compressor and the rest in the accumulator, which is it? Another issue is when oil is added to the compressor before installing, how do you keep it from draining out while you wrestle it in position? You may have plugs of sort, I don't and may have to add the oil after installing, somehow.

iceman2555 on Wed July 24, 2013 10:55 AM User is offlineView users profile

It is ALWAYS necessary to determine the correct amount of lubricant within the compressor prior to installation and start up. Adding app 2-4 oz to the compressor is the industry norm. Adding 1/2 system charge to compressor, the remainder to he accumulator is a long practiced procedure and truly acceptable. The accumulator and evaporator are system lubricant reserves for the compressor. Adding lubricant to the compressor must be completed in the correct location also. Some require in the suction port...others thru a fill/drain plug in the compressor. Failure to add to the correct location will result in premature compressor damage and possible failure.

Adding lubricant to the compressor has not been a industry problem...yes, at times it occurs....the largest issue for compressor longevity due to lubricant problems is a possible undercharged/leaking/or restricted system. Each or a total of these events will result in a premature compressor failure. See it all the time. Heck, this lack of lubricant flow is the major cause of OE compressor failures. Maintain refrigerant levels to OE specs and ensure proper engine cooling performance and the system should remain viable for many years.

Learned over time to not trust labels....never know if too much...too little...type....quality....always suggest to drain and refill. Not sure what Ford's recommendation is...typically what is drained out of the old unit and add that amount back. However, this is not always a valid approach. This was typically a resource for charge rate for the replacement of that item only.

Adding lubricant to the unit and rotating is a suggested procedure....insures lubricant of moving parts prior to start up and aids in decrease of possible compressor noise from a 'dry' start up. It also a good idea to add lubricant to the compressor...re install the port covers and stand the compressor up on the driver (front of clutch) for several minutes. This enables the shaft seal to be properly lubricated prior to start up.

Insuring that the compressor is lubricated at start up and during operation should be considered one of the most important steps is a successful compressor replacement. It boggles the mind that someone will install an engine and insure that all the components are properly lubricated...primed....quality lubricant....new oil filter....etc and yet install a compressor on a system that is or could be totally trashed inside...have not idea of the amount or quality of lubricant remaining within the system....never rotate the unit (prime it) or insure sufficient refrigerant to maintain lubricant flow at start up...and then 'bitch and complain' when the unit is noisy or fails after a short run time.

Maintaining compressor integrity by keeping the port plugs in place during installation is a good idea. Exp when the unit has to be rotated in multiple plains prior to bolt in....keeps the lube where it needs to be...in the unit...not on your hands.
Also a proper remanufactured or new GM compressor is almost impossible to rotate by hand. A mechanical advantage must be used....spanner wrench...clutch turning tool....no do not use the 6' channel locks to rotate the unit.

Lubricant is the 'life blood' of any reciprocating part and a compressor is no exemption. Get it lubed....keep it lubed (recharge amount/restriction in system), maintain proper cooling and it should last for many years.

-------------------------
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

wptski on Wed July 24, 2013 11:31 AM User is offline

Thanks for the detailed reply.

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