A/C not cooperating.
 

Yesterday we tried to charge the A/C. For some reason the freon wouldn't go past the valve. We pulled the compressor, verified that the service valves were open, Hooked the can to the valve and verified it was working, and put it all back in the car. But when we start the car and hook the can to the valve it spikes the gauge and nothing makes it into the system. For some reason the freon isn't getting past the valve, even though it worked fine when we had it out of the car? We even tried two different hoses. Couldn't get it to work.
Don't have time to mess with it till afer the move. So all you OC guys put on your A/C thinking caps. You have about a week to think it over before I start calling you out.;)

If you are using refrigerant hoses the angled end of the hose goes on the suction side of the compressor. In the hose there is a stem that will engage the schrader valve on the compressor.

I think Brian may have the answer -- in the hose end is a little plunger that's supposed to depress the valve and allow the refrigerant to pump from the can into the compressor. Check to be sure you haven't installed the hoses on your gauge manifold "bass-ackwards" (i.e., with the little plunger at the manifold end rather than at the compressor end of the hose).

Good luck.

Whatever you're using to hook the freon to the compressor, junk it and get something else. Also check the high side and low side BEFORE doing anything. Make sure that there is not a blockage in the system.

When the enginge lid is open and the AC is on, you should run a small shop fan across the condensor coils to keep the system from getting too hot and burning out the compressor.

Remember to evacuate the system and pull a vacuum to 30in for at least 45 mins.

I used to fly into Warsaw Indiana all the time!!! I wish we could have gotten together and had one or 20 and talked cars.

About your AC problems........just remove it and you won't have to hassle with it. :)

Brian

Hey Shawn

Did you check out this post http://forums.pelicanparts.com/porsche-911-technical-forum/285279-c-wont-recharge.html

If you have the old York compressor they have stem valves and not shrader valves. You need to open the stem valve in order to access the system.

If you converted to 134a refrigerant and have the quick connect fittings, check the quick connect fitting from the gauges. On some 134a manifold fttings, once you attach the quick connect fittings to the system, you need to turn a tumbscrew to open the valve.

Like I said to you in a previous post if you don't have someone who know what they are doing, don't mess with the a/c because you can hurt yourself.

If you are in the Land of the World Series Champions, give me a shout and I could probably help you with the a/c.

Re: A/C not cooperating.
 

Thrown'n da hamer,

Have you pulled a vacuum on this system?

You are not using one of those a/c refrigerant "kits" from one of the bigbox auto parts stores.... right?

You are NOT connecting the hose from the refrigerant can to the "high" side connection on the compressor (compressor to condenser)
with the engine running... right! :eek:



!!!!!!!!!!!!!!!!!!!!!

How come everytime I post a question everybody climbs under the desk and covers thier ears?:D

Please re-read the original post. We used TWO different hoses and neither one would let freon into the system while the compressor was in the car. We pulled the compressor out of the car. We verified the service valves were open and while it was sitting on the garage floor verified that the freon was getting past the valve. IE we hooked the can to the valve and blew a small amount into the compressor and out the opening that hooks to the hose. I had a liscensed A/C tech at my house that is allowed to discharge 50 ounces of freon a year so no wigging out.

The system is void of freon, I replaced the dryer and changed the compressor oil over for the R134a freon. If I can assume the valve works since it worked on the garage floor then there must be some kind of blockage somewhere.

Your goint to have to do the obvious. Test each component and hose seperately. You might as well run flush fluid through to do it. Remeber not to run flush fluid through the dryer or expansion valve.

Whoah, someone missed their valium or coffee dosage.
We can't read minds through the threads.
ASSUMING your "ac technician" knew what they were doing you would not be posting here.

So, how long did you pull a vacuum on this system?
If you did pull a vacuum, did the low side gauge register a max depth rather quickly?

Is this a Nippon or York?

Just so no one reads what I wrote out of context I am reposting my statement as it was meant to be read.

I have never taken any valium but am a little short on coffee at the moment.

The compressor is the original York.

The A/C tech that came to my house is a good friend of mine and runs a successful business. He came over to help charge the system assuming everything worked and it just needed a charge. He has never worked on a Porsche A/C system before and wanted to verify the service valves were open before we started. He said if the service valves were closed it would show vacuum but only be pulling vacuum on the hoses. He hooked the bottle up and nothing went in. So he turned the valves all the way in and nothing went in either. At that point we pulled the compressor to see what was up. The freon went in when the compressor was on the garage floor with the service valves turned all the way out. Seemed odd. We put it back in the car and no freon would not go into the system. He didn’t come prepared to do a complete tear down of the system and troubleshooting. He spent more time than he had allotted and had to go to his son’s baseball game. So after he left I posted the question.

Capt. Carrera, Thanks. That’s what I figured. I don’t have time right now. I suppose I will have to address this after the move.

Ok, so I've had my first 16 oz of coffee and I'm chilled.

The York has "service valves" on the hose manifolds attached to the compressor. You connect your service hoses to the R12 ports on the manifold. The "service valves" will block off in the manifold between R12 port and compressor. Turned fully CW closes, turning CCW opens.
So, if the service valves were closed and you tried to pull a vacuum on the system you would only be pulling a vacuum between your service gauges and the hose connection at the manifold on the compressor.

Which leads us to the unanswered question.... did your ac tech hook up a vacuum pump and pull a vacuum on the system" and if yes where the service valves open before you tried to put refrigerant in the system?

We never got to that point. He said the valve is usually open CCW but wanted to verify before he put the vacuum to it.

I have also had my dose of coffee and fell much better now.

Here is what you can do:

Assuming there is not refrigerant in the system.
Install a new drier.

Add 6-8 ounces of ester oil to the compressor.

1) Hook up your service gauge hoses to the compressor manifolds.
2) Connect your vacuum pump.
3) Open the service manifold nuts "nearly" fully CCW. I say nearly full CCW because I recall on some if you go full CCW it will close again.
4) Pull a vacuum for 3 hours.
5) Lock up your service "gauge manifold" valves fully CCW and turn off the vacuum pump.
6) Take a small tip marker and mark on the face of the low side gauge where the needle is, should be close to -30 in.
7) Go have a Becks or cup of java and wait 20 mins, not more than three Becks.
8) After 20 mins. see if the gauge needle on the low side moved back toward "0". If not and it is still where you made the mark then you have a good "gross leak" check. If if moved back toward "0" then you have a leak somewhere between the service guages and the cars system.
9) If the gross leak check was good THEN you can put the refrigerant in the system. In order for the refrigerant to go out of its container into the system the system pressure must be lower than the pressure in the refrigerant container.
10) You can do an initial charge or partial charge through the high side manifold WITH THE ENGINE OFF using liquid (refrigerant can upside down), or if your expert has a heater blanket for the refrigerant can you do do liquid or gas..... making your final charge using a P&T chart, your expert should know.

I think you should take your car over to his place and have him hook up his equipment to diagnose what's going on. I assume you connected the refrigerant to the low side valve. Sounds like he tried to charge the system (liquid) through the high side valve (no, no and dangerous).

What are the gauges reading?

Or maybe the compressor is blocked or not rotating (check the clutch?). Even then, refrigerant would still fill up the low side of the system (low pressure hose > evaporator > expansion valve).

BTW, Porsche A/C has the same basic components and works the same as any A/C system. Nothing personal, but does your friend own or work at his A/C shop?

?
Sherwood

<i>BTW, Porsche A/C has the same basic components and works the same as any A/C system.</i>

.....hmmmmm, no.
The 911 uses a drier and an expansion valve to meter the refrigerant, the compressor is cycled by the thermostat directly. Other vehicles can have orifice tubes with accumulators and can cycle the compressor by various combinations of switches and sensors.

Sherwood, I realize in California a 911 is a common sight. In northern Indiana I may as well have a pre-war Bugatti. He just wanted to be sure he understood the system. Most cars he has dealt with don’t have a A/C condensor on top of the engine.

I am moving on Saturday. I don’t have time to deal with it at the moment. After the move from a 911 perspective I will be in much better hands.

A MOVE!

who's bringing the beer and burgers?

I will bring both if you charge my A/C.;)

"Other vehicles can have orifice tubes with accumulators and can cycle the compressor by various combinations of switches and sensors."

Basic A/C components are the same (compressor, condenser, receiver/drier, expansion valve, evaporator). There are variations of control mechanisms, and the receiver/drier is now placed inside the condenser on some vehicles (sub-cool condenser). Those other systems are just a variation of the basic A/C system.

I wonder why the A/C tech was thrown off by the location of the condenser? It doesn't matter where it is as long as it transfers heat to atmosphere.

I hope you get it working soon.

Sherwood