A/C won't recharge

[Sweeny Todd]

Howdy,

I need some help, please. Hopefully, someone knows what's up.

Here's the facts.

I replaced all my o-rings with the R134 compatible o-rings. I replaced my drier with a kuehl from Griffiths. I drained oil from the compressor and lines, I then filled it back with about 4 oz. total R134 compatible oil. Forget the name, right now. This is per the specs in the Bentley.

I have manifold guages attached - red to the side that goes to the condenser on the engine cover and blue to the other side. I sucked it down with my 5CFM Electric vacuum pump. It'll hold 3 microns for half an hour.

Now the problem. I connect a can of R134 to the center feed on the manifold guage set. I then start the car and slowly open the low side - blue - vacuum side - on the manifold set. Sounds right, right?

Ok. Then why does nothing happen? There's no temp change on the can, the needle on the guage set doesn't move, it still shows a mild vacuum, but it doesn't change. The can still has pressure, if I loosen the puncture seal refrigerant escapes so I know there's pressure in the can. What am I doing wrong here?

Hal

[Hugh R]

Do you have a high/low pressure switch? Is the magnetic clutch turning on the compressor? Can you loosen the center hose off of the manifold and get gas escaping? Some hoses have one way valves that you must remove on the center hose.

Just a few guesses, good luck.

[Sweeny Todd]

Thanks Hugh.

Didn't think to look for air coming out the high side. That would be a simple way to see if the pump is working. Unfortunately, I'd have to waste a can of R134 to do it.

The 911 does not have a high/low cutoff. The compressor clutch does engage when the a/c is turned on in the cabin - which it was.

I checked the other service hoses and they are open. They don't have valves in them, so I doubt the service hose for the center has one either.

Any other ideas?

Hal

[Grezdlitn]

I had a similar problem once. Try disconnecting your low side (blue) and examine the hose connection. There is a small stem in the end which must be long enough to depress the schrader valve on the compressor. If it doesn't you can pull it out with needle nose pliers and adjust. You may be only pulling a vacuum on the guage and hose set.

[Sweeny Todd]

That was it. Well, almost. As it turns out, there's a pin in one end of the service hose and not the other. The end with the pin was plugged into the guage set. Turns out, I never pulled a vacuum on it, at all.

Oh well, back to square one.

Thanks!

I love this board.


Hal

[Grezdlitn]

Hooray!!! I love this board to......