Charging 1988 911 R134 A/C

[rdoine]

I was charging the R134 a/c system using gauges and getting readings on the low side of about 30psi and on the high side of about 150psi. The high side port started spewing green refrigerant so I shut the car off.

What would have caused the refrigerant to discharge from the high side port when the readings were within the acceptable levels, according to the gauges?

I had only added a 12 ounce can of R134 and a few ounces of oil.

Thanks for any help provided.

Randall Doine

[DRACO A5OG]

It was leaking while the gauge was on?

Or After you removed it?

If after your stem valve is loose and needs tightening. If during, the gauge is leaking at the connection.

Jim

[rdoine]

The gauges were still connected and the can of freon was reaching the empty point. The readings seemed ok and all of a sudden the freon started spewing out.

Hope that helps.

Randall

[rdoine]

Oh, so if the hose was connected more firmly, it would not have happened?

Because it seemed as though I needed to add a bit more freon but I stopped when the discharge occurred.

Randall

[DRACO A5OG]

Was the refrigerant coming straight out of the "port" or out the side?

A pic of your "port" would really help. Who installed the after market fit of the r134 fittings?

[DRACO A5OG]

Originally Posted by rdoine

Oh, so if the hose was connected more firmly, it would not have happened?

Because it seemed as though I needed to add a bit more freon but I stopped when the discharge occurred.

Randall

Yes, r134 system uses a quick release connectors, make sure it is firmly attached/ actually the quick release valve is fully engaged.

[rdoine]

Sorry, I don't know who did the conversion. It was like that when I bought the car about 4 years ago. Car had 14,600 miles on it when I bought it.

But, the quick connect had been in place for some ten minutes or so when the freon started to spew out around the connection. So, your thought that the connect may not have been secure could be right on point.

When I get back into town next weekend, I'll re-attach the gauges and see what happens. Sorry, I can't do a picture until I get back.

Randall

[rdoine]

Ok, got back home, bought a new set of gauges with better connectors. Hooked everything up and I'm getting readings of about 32 on the low side and 270 on the high side.

I cannot seem to get refrigerant to go in or it seems to take forever. Can does not get cold. The connector gets cold if I run the rpm up and hold them there for a minute or so. But, I can't get the can to empty out. I'm trying to get the low side closer to 40.

Do I have a 1) bad compressor, 2) too much refrigerant, or a blockage somewhere?

Any thoughts? I can always take it in and have it looked at but I would like to learn how to do some of this myself. I've owned quite a few 911's and worked on a lot of areas, but never the a/c.

Thanks for any guidance those of you smarter than I might have.

Randall

[Mitch Leland]

I know in my case when my A/C shop tried to connect his quick couplers to my R134 adapters there wasn't enough clearance between the compressor and the R134 connectors. So he took a grinder and ground off one side of his coupler to gain some clearance so his coupler would go all the way down onto the connector. I'm wondering if you had that problem? The hose coupler was never seated onto the compressor 134 valve connector?

[rdoine]

That may have been the case with the gauges I used when it happened but I bought new ones yesterday and they go on just like they are supposed to.

Finally got everything working with the gauges as they should. Finally got refrigerant to go into the system.

Best I can get is about 60 degrees from the center vent while driving down the road. I guess it's better than nothing, eh?

[Mitch Leland]

Originally Posted by rdoine

That may have been the case with the gauges I used when it happened but I bought new ones yesterday and they go on just like they are supposed to.

Finally got everything working with the gauges as they should. Finally got refrigerant to go into the system.

Best I can get is about 60 degrees from the center vent while driving down the road. I guess it's better than nothing, eh?

I bet by now you might not have the correct amount of oil in your system, you've probably have gotten moisture into your system. I've done a lot of free lancing on my A/C and Charlie Griffiths has finally made a believer out of me. He says that using refrigerant cans isn't going to give you a good charge with good numbers.

I paid $70 and got a good evacuation, vacuum, got the correct amount of oil added, the correct the charge with a $5,000 A/C refrigeration machine. Unless you're really qualified I think for the average guy we're spinning our wheels to be charging our own A/C systems. You can do it, but you're not getting the maximum results.

[megerian]

I also have an 88 thats been converted to 134a. I recently did a recharge using a can from the auto parts store. The reading was very low when I started and by the time the can was empty, it was reading correctly. But... After all that it barely blows cool, certainly not cold. We have checked for leaks with the UV stuff. So I agree with the previous post that it's inevitable that a professional recharge will be needed.

[fred cook]

In order to get pretty cold air from the a/c in my 1980 SC coupe, I have had to replace the entire system, upgrading compents when possible. I have replaced the hoses with barrier hoses, added a Rennaire Desert Duty front condenser and evaporator, pro cooler and a new stock type rear condenser. Now I can get about 45 degree air on a 95-100 degree day (in town driving). On the highway, the car gets cool enough to be able to run the fan on the middle setting. I also have adde the Khuel vents center and ends. This is using R134a. The a/c can be made to work, you just have to be willing to open the wallet a bit. By the way, there is a move afoot to get rid of the R134a refrigerant. Look for it to start climbing in price soon.

[dshepp806]

Originally Posted by fred cook

In order to get pretty cold air from the a/c in my 1980 SC coupe, I have had to replace the entire system, upgrading compents when possible. I have replaced the hoses with barrier hoses, added a Rennaire Desert Duty front condenser and evaporator, pro cooler and a new stock type rear condenser. Now I can get about 45 degree air on a 95-100 degree day (in town driving). On the highway, the car gets cool enough to be able to run the fan on the middle setting. I also have adde the Khuel vents center and ends. This is using R134a. The a/c can be made to work, you just have to be willing to open the wallet a bit. By the way, there is a move afoot to get rid of the R134a refrigerant. Look for it to start climbing in price soon.

Yeap, it's (R134a) definately on it's way out!

BEST!

Doyle

[rdoine]

Thanks for everyone's input. It has been greatly appreciated.

Finally got the right amount of refrigerant in and the pressures where they should be for the 95 degree weather we had yesterday.

Took the car out this morning and got 40 degrees at the vent on low fan speed and 50 degrees at medium.

I'm satisfied with that for now.

By the way, I did add some oil before I started adding the refrigerant. But, a good vacuum session would definitely be a good idea.

I'll watch it for a few weeks and then decide if I need to do anything else.

Eventually, changing all the hoses, condenser, etc. is on the list.

But, it's not doing too badly for a 23 year old car with 29,000 miles on the clock.

Thanks again.