89 Crown Victoria - AC Oil Question
 

The AC high pressure hose blew on my wife's car. Before replacing it, should I add oil to the system? I have Ester oil in a pourable can (not pressurized). If I should add oil, what is the best way to add it.... a few ounces in the suction port of the compressor and accumulator, something of that nature?

Also, my memory is flawed somewhat (age)..... I've read (somewhere) not to open the high pressure knob on the AC gauge set, but then I've read in my manual to check the high pressure with the engine running, very confusing. Advice on this point?

A few years ago, I opened that high pressure knob on another gauge set and blew the high pressure gauge hose apart..... my goof or bad hose?

Joe

I was hoping someone else would respond to your question, but no takers!
When you connect the manifold gauges to each of the hi and low side ports the reading on the gauge is the system pressure at that time. The only time you open the low side is to pull a vacuum or admit either compressor oil or refrigerant in gas form. Your system uses R12 does it not? You can obtain compressor oil for R12 systems in small pressurized containers(2 oz). This way the oil is moisture free and clean. You add it to the system after pulling a vacuum on the system for a minimum of 45 minutes to an hour.It is added through the low side hose from the center of the manifold hose through the open low side manifold valve. There is no need to open the high side valve at any time except when evacuating the system and pulling a vacuum other than that keep it firmly closed.
You may need to jump the low side pressure switch contacts to get the compressor to run a little longer so you can get the refrigerant into the system quicker. Keep in mind the lo side switch is to protect the compressor if the system runs too low on refrigerant. If you feel the refrigerant isn't going in fast enough remove the jumper from the plug to allow the system pressure and lubricant to stabilize.
I believe your hi side manifold hose blew due to deterioration/age.
I always remember the saying about some so called old things, especially, "The older the fiddle , the better it plays" ! Hope I answered some of your concerns,,,,, hanky

89 Crown Victoria - AC Question
 

Hanky..... Thank you very much my friend, I do appreciate your reply. Yes, you've answered my questions to the letter. My main concern was about opening the high pressure side with the engine running..... some of the manual is rather vague on that point, leading one to lean either way.

I did years ago open the high side valve with a engine running and promptly blew the high pressure line apart. This manual had me wondering if that was just a weird happening or is opening that valve with the engine running really a no no. Obviously, after reading your reply, that is a no no.

I did read that with the unit pressurized and the engine NOT running, I could open both for a static reading..... that piece of instruction was pretty well cut and dried.

So..... I thank you again for the reply. Should you have a problem with a Evinrude or Johnson outboard, keep me in mind. (Joe..... 30+ years with OMC)

Thank you for the offer! I did manage to go to the OMC school in Parsippany , NJ , many years ago and was surprised to learn the only difference between an Evinrude and a Johnson was the color of the paint! At least it was at that time! I'll bet we could exchange some real stories. Thanks again, ,,,,,,,,hanky