You don't need to remove a hose to undo the compressor shaft nut. You just need to hold the clutch with an oil filter wrench with one hand while you loosen the nut with the other. In fact, you can remove the pulley and clutch coil as well without unbolting the compressor or its lines.

928intl has rebuilt 10PA20C compressors. The same compressor was also used in '88-'96 corvettes, except they have a serpentine belt pulley, a different manifold and a different clutch coil connector, but you can reuse all of those components from your old one if you choose to go that route. Cheapest possible solution (but risky) would be to get a used corvette compressor like this.

Dan
'91 928GT S/C 475hp/460lb.ft

 

Dan,
Thanks for the input. I could not get to the front bolt as the hose is routed in front of it. Therefore had to remove the hose to get to the bolt.
I am actually looking for a new compressor as the clutch bearing does not feel smooth and I don't want to be redoing it again. My compressor is the new type and does not look like what you showed on the link, but maybe it is because of all the additional items on it.
Thanks

 

I have no experience with this vendor, so I have no idea what you get as far as customer service or product. But, they do have the lowest prices that I could find for a new Denso.

http://catalog.importrp.com/item.wws?sku=656 43003 122&itempk=231953&mfr=DENSO NEW&weight=16.610

Good luck.

JD

 

Rear evaporator leak fix:
It seems that most rear evaporators leak at the junction where the copper pipes enter the aluminum evaporator.
I have sucessfully fixed many this way.
Clean each junction with a wire brush and then acetone. Apply a vacuum to the evap and then apply JBWELD epoxy to each junction. Remove vacuum and allow to cure. I have never tried the 5 minute epoxy but it may work. Other epoxy will probably work. My theory is that the vacuum sucks the epoxy into the failing part.

Earl

For some reason the front evaporator does not seem to have this problem.

 

Thanks, Earl!

 

I got my compressor yesterday. I was reading the literature/manual that came with it. As part of the installation procedure, they outline the removal of the oil from the existing compressor and also take the oil out of the new compressor, then put back the amount of oil in the new compressor equal to what came out of the old compressor.
Is this really necessary to go through this procedure? Oil also leaked out of some of the joints when I was changing some of the o-rings. It is very hard to quantify how much oil was lost. So it will be a best guess on how much to put back in addition to what came out of the old compressor.

 

Correct: it's going to be a best guess. The assumption behind the procedures is that no oil escaped from the system and that by using the 'old' oil amount in the new compressor that the overall level of oil in the system will be proper.

This of course assumes also that you've already put the proper amount of oil in any other component that has been replaced or flushed. The receiver/dryer is likely to be one such component. If you flushed the rest of the system of oil then you'll need to add the amount of oil specified for the whole system.

Typically folks add the required (guess) of oil to the compressor under the assumption that operating the system will circulate the oil.

Of course that very first assumption is likely to be false because oil does escape from the system due to a) disconnecting lines and b) the natural course of leaking refrigerant taking some oil with it. So the trick is to guess about how much oil has been lost.

I always try to capture oil for later measurement as it comes out. Typically this is only at the under-car lines. I then add to this, the amount that comes out of the compressor. For filling the new compressor I take the measure of all the captured oil, add the spec amount for the r/d and a half-ounce to account for additional escaped oil. All that goes into the compressor.

This, of course, only applies if I didn't flush the system. I may add more "guess oil" depending upon the history of the A/C system. If it has a history of just 'topping off' the charge over the course of many years I will add more oil. This is most common with r134 systems - factory or converted. If this history is too full of 'topping off' or if there's no history, then it's best to do a flush and start with a clean system and the total system oil amount.

It is possible to over-oil the system in which case it will prevent efficient transfer of heat from the evaporators.

HTH.

 

I made a flat guess and things seem fine. I suppose if I under did it, eventually it will break, and if I over did it, the cold air wouldn't be as cold. Thus, I believe, at this moment, my guess is OK, or the tolerance for a wrong guess. Is generous.