hans57

All,

My air does not blow cold, I think it is just low on charge. I know it cannot just be recharged without a complete leak check. Are there any known areas that are prone to leaks? Are there any other major areas to look at that causes the air to not work? The climate control panel is new, and I think the compressor engages with the button. I am looking for some tips before I take it to a shop for repair.
Thanks!

springer3

Look for any wet-looking refrigerant hose ends. The shop should have a "sniffer" capable of finding leaks in the oz/year range. Compressor seal leak if you can find one anywhere else.

What refrigerant are you running? If you are still on R-12, you have a very old system and are probably due for the conversion to R134a.

If you have been converted, and it still blows cold after being off for the winter, your leak is pretty small. A can of gas or less per year is a pretty tiny loss. I would top up and enjoy another season before I spent big money on a leak repair.

hans57

Springer,
Thanks for the advice. I am not sure if it has been converted, how can I tell?

dfinnegan

There is supposed to be a sticker, or, at least, some hand writing on an existing sticker, indicating that it has been upgarded.

The valves are different for R-134a. They look like standard (schraeder) bicycle tire valves. Mine have red and blue caps that screw off, like the valves/caps on the car tires, actually.

I think the original R-12's were black; not 100% sure on this.

BlackWidow964

R-12 valves look like regular bicycle/auto tire valves, and are threaded on the outside.

R-134a valves are much larger in diameter and are not threaded on the outside.

jneteler

I had the same problem. Took it into a specialist shop this Saturday and they recharged it with R12 and a dye. They said come back in two weeks or so. Also noted that the pressure was low when running.

It was nice going for a drive with AC working again.

Regards,

JNeteler

hans57

Mine look different, the valves are facing towards the side of the car,with only one covered with a black cap. They are threaded on the outside so it looks like they must be R 12. Now, to find someone that will do testing/refill without a total system rebuild proposal.
I wonder, when is the time to convert to R 134a? How much work can I do myself? Costs?

ducnine

Anyone know ballpark what the conversion should cost?

MisterRisky

Be careful if you take it to a shop that is not used to Porsche ACs. Nothing magical about it, but it does run at a lower pressure than some other systems. I am of the opinion, however, that they should not be measuring pressure as they should evacuate the system totally and add the gas back by weight.

When I got my car it was actually over charged with R 134a.

jneteler

Is there a specification for the pressure? Does it depend on the refrigerant gas type?

Regards,

JNeteler

J richard

The low pressure switch keeps the compressor from engaging if you are completely dry, so odds are you just need a recharge. There are several areas they leak, getting some dye in the system is your best bet. The evaporator on these cars is prone to corrosion, and then they leak, if that is the case you will get dye where the condensate drips on the garage floor out of the bottom of the car, on the right side just behind the wheel, sort of where the fuel pump is.

The conversion over to R134 requires replacing all the rubber lines with barrier type hoses, since the R134 can pass through the r12 type hoses. I think the extra cost of the r12 fill up is worth it, it is more efficient than the r134, let alone the cost of conversion and it's not as "green" as everyone thought it was anyway...

dfinnegan

So, what is the expectation if the hoses are not replaced when the R134 conversion is done? A season? Less? Two years? How fast will it pass through the hoses?

Thanks.

MisterRisky

I was under the impression that our hoses were the barrier type as Porsche anticipated the change over from R12. I believe that I read that in Adrian's book.

JNeteler, the best places to get pressure info is the workshop manual or Adrian's 964 book. You MUST use a dual gauge to read the pressure. It is tempting to use a cheap low pressure only gauge, but it is easy to screw things up if you use only the low pressure reading. If you want to DIY, get a dual pressure gauge from somewhere like Harbor Freight Tools.

911URGE

Just had mine done today. Lost all freon and the shop stated 9 times out of 10 a compressor seal is the issue. That was my issue. Look on your engine lid and see if you notice more than normal amounts of dirt, oil or grime where the compressor sits as thats a huge clue the compressor seal went south.

As for R134a - stick with the R12. PO did 134a conversion without replacing hoses on a solid, leak free system and he was recharging the system at least once a year. I took it back to R12 and got colder vent temps and went 2 yrs on that before my compressor seal let loose. YMMV.

Bearclaw

I just went through this, and chose to do an R12 charge instead of converting.
I think a lot of past conversions were done on the notion that there would be no R12 left in the world to be had. Proved not be the case.
Every HVAC guy I know has a big supply of it.