rmr25

The a/c temp was running barely cool, so I figured a refrigerant boost was needed. (Note: the PO had converted to R134a and replaced the compressor, expansion valve, r/d, and low- and high-pressure hoses in '97, about 12,000 miles ago.) I had 1/2 can of freon handy that I put in, but only got about 10 psi on the gauge. The sight glass showed a milky stream. The next day, armed with several cans of refrigerant, I resumed recharging. Only to discover 0 psi! Since the compressor clutch wasn't operating, I used a jumper on the pressure switch plug terminals. But I couldn't get any freon to flow; the sight glass was blank. I see no external signs of leakage around the compressor, fittings, hoses, or expansion valve.

Does all of this sound like compressor failure? Or is there something else I can test? I'll deeply appreciate any suggestions.

tomcat

One thing I would check is the 134 fitting. The one we put on DonT's R-12 fitting pushes the schraeder (sp) valve down by default. And the only thing, it seemed, that held the 134 in at the valve was the plastic cap. Maybe the fitting was f'ed up, but we decided to leave the fitting off.

SteveG

So what is the pressure in the system now? If you lost pressure overnight and there isn't oil visible, I would think the valve.

If there is freon, did you try 12V directly from jump post to the compressor? Only run it for short period if there is no freon in the system. Search here, there is lots on this recently.

If you are jumping the newer 4-pin low pressure plug, you need long narrow spades, jump the two black wires together. I could not get it with simple DVM probes; I fabricated from a woman's hair clip a longer spade. That enabled me to top off my system.

griffiths

1) What type of equipment are you using to charge the system?
(i.e. gauge set with hoses or a store bought can with just a charge hose and simple gauge).

2) Are you charging through the low side or high side?

3) Is the refrigerant can right side up or inverted?

4) Do you mean "freon" as in R134a refrigerant or R12 refrigerant?

5) Is this a front air car or do you have rear air too?

6) When you jumped the pressure switch did the outer hub of the compressor pull in and turn with the pulley?

rmr25

Guys:
Thanks for the suggestions/questions.

Here's the status:

There is now no pressure in the system.

1. Equipment: I'm using a manifold gauge set (three hoses; red, blue, and yellow.)
2. Charging: through the low pressure port.
3. Can when charging: right side up (not inverted).
4. Freon: R134a.
5 System: both front and rear air.
6. Compressor clutch: it does engage when I jump the pressure switch. I can also feel the revs drop slightly.

As I said in my original post, with the compressor (clutch engaged) running and the freon can in the upright charging position, I see no freon flowing in either the gauge sight glass or the sight glass near the r/d.

griffiths

Pull a vacuum on the system for about 1-1.5 hours.
Then recharge the system through the low side (gas method; can upright) filling it with approximately 85% (weight value) of the OE R12 charge using R134a.
Run the system (parked, idle, max cold, windows up) for 10 minutes and document the ambient temperature, low and high side pressures (at idle). Let us know what you get.
Use an electronic leak detector (sniffer) to sniff the following with the system running:
Hose connections at compressor, evaporator pipe (side wall to compressor), condenser and drier connections, R134a charge port adapters,front expansion valve, remove rear grill and sniff the rear expansion valve as well as the solenoid valve back there, if you want to be thorough pull back the carpet and check the refrigerant lines there and sniff front vents at low fan speed and then locate condensation drain tube for front evaporator and turn off system and quickly sniff the drain tube.
Let us know where you found the leaks.

Ted928

rmr25,

This may sound stupid, but you may not have the filling valve opened. I had this problem with the cheap gage set I bought from Habor Freight. If I remember correctly, the instructions were in error. I think it was the valve that attaches to the low side that turns the opposite direction.

rmr25

Ted928:
Midst all the confusion I was floundering in, you spotted the problem! Yes, I had obtained the HF manifold gauge kit. Turns out, the Low Pressure coupler/valve was defective: it would not open in either the clockwise or counterclockwise positions. By contrast, the High Pressure coupler/valve worked fine. As you can see, with the low pressure valve inoperative, I couldn't get anything into the system just to troubleshoot, let alone make it operate correctly. So I'll be negotiating with HF for a replacement.

For all who responded, again, my sincere thanks.

Bob

griffiths

Sounds like Ted and and Tomcat split the winning prize of one years supply of cold Becks.
RMR.... you're buying. Right?

rmr25

Griff:

OK. But don't I have to wait until December 31st? Maybe there will be some offsets to my Beck's debt.

griffiths

Strategically you would be better to pay off the debt today.
Consider the following:

A) Goodwill - by setting down a few cold ones immediately the responder(s) will
correlate the cold glass before them to some action they must have taken. This will help to enforce or compel quick responses to future questions.

B) Inflation - with the global energy demand cranking up the drill bits and the shallow refinery infrastructure there will be a great pull for capital, hence a rise in borrowing rates which will simply lead to inflation and higher brewsky costs.

Consider a home equity loan !