Compressor not holding vacuum

[Cusser]

Even though this site's software won't "remember me", I do remember that my 1984 V6 Jeep Cherokee had a Sanden compressor.

When it seized in the early 1990s, and compressors were for this were like $700 and unavailable at that time, someone offered to swap the rear plate to a new/different Sanden, still expensive.

Well, I had two little kids to feed, I bought a used compressor from a Jeep wrecking yard for $75, and that worked fine.

[tbirdtbird]

I had no idea that a Sanden would have isolation valves like a York. Those were the good old days.
On residential equipment the condensing unit used to come with built in hi and low pressure cutoffs, those are gone too

[Cusser]

I had no idea that a Sanden would have isolation valves like a York. Those were the good old days.

I liked the manual isolation valves; I installed that used compressor and only lost a tad of R-12. I used a 1/4-inch socket upside down, using a L-shaped allen wrench to turn the socket on the 1/4-ich square isolation valve stem. There were aluminum dust caps to protect the valve stems, but the caps did not have any sealing function.

Maybe something like this

[Tim]

Yep, if a compressor had tube-o connections. You may see them used. Not just a York item.

[tbirdtbird]

yep, that is it. There is a "refrigeration wrench" with 4 ratcheting sizes with square holes for various sizes of stems.
Also works slick for using small size taps which always have a square shank

I worked on a '61 RollsRoyce once that had isolation valves on the York

61p-TB9lbwL._AC_SL1500_.jpg (41.59 KiB) Viewed 6384 times

[fhorta]

Put freon in and seems to be all good. Thanks soo much. Now it Looks like i have a bit more troubleshooting. Ac only blows through defrost vents. Ideas? (:

[Cusser]

Now it Looks like i have a bit more troubleshooting. Ac only blows through defrost vents. Ideas? (:

My 1984 Jeep Cherokee had similar issue. Mine had three vacuum-operated actuators to direct its air flows. Two of these were identical part except for a paint color code, as different functions, and the third was different from these. I was poorer then, bought replacement actuators at the parts yard, took my hand-held vacuum pump with me to test before buying.

NOTE: some term these "motors" even though they had no motor !

[tbirdtbird]

check vacuum lines, start at engine and trace rearward

[fhorta]

Ok. Thanks.

​​​​​​​I have put 2 cans of freon. Cans say they have a net weight of 12 ounces. Compressor originally takes 2.38 lbs of R12. According to a chart, that is equivalent to 2 lbs of R134A. I am coming up with 36 ounces of R 134A of freon to charge compressor. So I would need another can.  Is that about right? When I weighed full can, I got .75lbs

[tbirdtbird]

Please recall that you will not get all 12 oz out of the cans.
A pound is 16 oz
So 2.38 lbs is 38.08 oz, take 80% of that to get your 134 charge = 30.4 oz

Since you put in 24, I would add another 6 oz