yann986

Hi guys!

Went I bought my used Porsche, air conditioning was functional.
some days laters, no A/C.
I checked everything according the service manual, all components are in good shape (compressor engaged, etc.)
No error code via my Durametric cable.
Then I bought recharge R134a, but when I am injecting pressure always fall back to 0 after some tries.

Then, I am thinking that I have a leak...

I read about that, and I have options:
- Injecting stop leak like that:
https://www.napaonline.com/p/NCB00222
- Find the leak with a leak detector. I saw yellow can that you inject and you are suppose to the leak with a lamp an glasses...
Then repair where is the leak.
- Or change all O rings? And redo. I dont know too much about theses O rings...

I am not a fan of stop leak stuff... but I would like to have your feedbacks on this topics.
Does Boxster have some weakness at some place on AC pipes/O rings?

PS: I am just thinking at the same time I am typing here... from a completely empty AC system, how many cans are required? Perhaps I just not insisted enough?

Thank you.

Schnell Gelb

You need some specialized equipment for this. Why not take it to an a/c specialist? For example - How will you evacuate and vacuum the system?
First find the leak.
Next buy the Viton seals,then nylog or similar.You may be lucky and just tightening connections may fix it.

Macster

I'm with SG on this. I think an A/C specialist is advised.

The system needs to be evacuated and all the refrigerant removed -- if any is left -- and possibly some compressor oil.

The system is left at a very low pressure for a while to check for leaks. If any leaks are detected they have to be fixed. The system is again evacuated to confirm no more leaks -- and to remove any moisture -- then the right amount of refrigerant and any oil that removed during the previous evacuation is added back to the system and the system checked for proper operation.

Also, with a leak one has to be concerned that some oil was lost along with refrigerant and the system can be low on oil which can compromise the compressor's operation. Not sure how this is handled but the specialist should know.

yann986

OK then, You are right that it is certainly a good idea to go and see a A/C specialist...

Reason why I was trying to fix it, it is because I love to fixe issue myself :-) I fixed almost everything on my car, but it is true that for this one, not very easy without equipments and skills.

Thank you SG and Macster, I will let you know findings...

yann986

Hi guys,

I checked the AC compressor today, to verify...
And even if I can hear the motor drop a little, when I engage the AC, the AC compressor does not look to engage! The inside wheel of the compressor stays still, dont turn at all... I guess it should turn when AC is ON...

Here a picture of a video, motor is on, AC is ON (as you can almost read the text... it is not turning):



Am I good for a new AC compressor, right?

Yann

yann986

Perhaps only the AC clutch is dead?

Dave H.

you need to have steady system pressure before you worry about parts failing.

you have already stated that you have zero system pressure, so the low pressure switch is not supplying a ground to energize the clutch.

no pressure = no oil circulation, so an open low pressure switch = compressor protection.

yann986

Thank you Dave H.,

you have a good point! Then, I should stay on the leak theory first.

And, you know what, I just think that last time I clean front radiator it was not very clean (first time after I bought this car...)...
And A/C condensers look like this :

http://philipraby.co.uk/porsche-996-...ion-a-warning/

Mine are not as bad, but I remember a strange stain on the condensers... and it was a bit like the last photo...

Then, as I tried to add some refrigerant, I should have more "fresh" stain on the same spot... I will look at this soon...

Thanks.

yann986

Then, I think I found the leak.

As discussed, here photos of my front A/C condensers, I can smell an strong odor on the left side, that smell like the A/C can recharge...

I am good for new A/C condensers radiators.

Macster

Be advised if you replace say the condensers the Porsche factory manual gives the corresponding amount of compressor oil removing the old parts takes out of the system and this must be added back so there is enough oil.

For my Turbo the amount is 20 cm ^ 3 per condenser. But you need the amount for your car.

Do not remove the plugs for the condenser lines and connections until just before you install the new condenser.

yann986

Thank you Macster for the tip.
Make sense! When you think about it :-) (I did not think about that..)

I was not able to find the right amount oil needed when replacing one condensers for the Boxster. Nothing in the repair manual... or online... I saw that some people add some new oil directly in the new condenser just before install it. But put an approximative amount in it...

For you last comment, I think it is to avoid moisture, right?.
Make sense to change it right away after removal to avoid moisture to get in.

I think I am almost ready; new condensers, new o rings, some oil, and recharge with refrigerant.

Macster

Leaving the covers/caps on the connections is not about moisture. Once the system is back together the system gets evacuated and held at a real low pressure (vacuum) for used to be an hour. Besides being a leak test this removes any moisture.

If I had to guess, I'd say leaving the covers/caps on is intended to avoid getting something in one of those items, a bit of dirt, a moth, fly, etc.

yann986

Hi Guys,

Just to let you know that I did it, A/C is working now! :-)
I replaced two condensers (Added some new oil in them before installation.), recharged with R134a, and cold air came back!
I was surprise, I did not need to use too much R134a... but anyway it is working now.

Thanks.

Schnell Gelb

Since you opened up the system to replace the condensers ,there are other procedures to follow beyond just refilling with R134a. And replace the Receiver Drier. It is tedious but half measures w/o the correct equipment are seldom effective for long with a/c work.

sniperonhigh

No doubt it has been done before - but it doesn't mean it was done correctly. Failure to evac an a/c system will leave you with a system that doesn't quite perform 100% as a best case and a system with moisture in it which may corrode parts, plug the drier and/or freeze up and frag your compressor. If you are really wanting to DIY this job, at a bare minimum scrounge up a vacuum pump and some gauges and evac the system for a couple of hours after replacing your drier.

Or you can run it as is and hope all these other guys are wrong and maybe you got lucky.