Hi,

I noticed that my airco wasn't functioning anymore and at the Airco shop they detected that I had a leak in the system as it didn't hold pressure.
So they filled the system up and added leak detection fluid.

After one hour a pudlle of leak detection fluid had formed on my driveway underneath the car after I had parked it there. The pressure it completely gone, so it must be quite a leak ....

The spot where the dectection fluid left the car is just behind the middle / centre between the front wheels.

What Airco system component is installed here?
How difficult/easy is it to reach to check if it needs to be replaced or to check for a bad hose connection?

 

Dear Toon,
Most likely the evaporator or the plumbing too and from. Mongrel of a job. I would advise the first place to check is the expansion valve. This sits almost in the middle of the rear of the luggage compartment. You remove a couple of small screws and take off the plastic cover and you will see it. After that check the pressure switch which is on the left of the expansion (right as you look from the front).
Ciao,
Adrian
964C4

PS: You cannot miss these components they have metal tubes into them.

 

Adrian,

I have checked the pressure switch and the expantion but no apparent leaks from there. This was also my first concern after I had replaced the LH front blower that I might have damaged the airco lines/connections but those are all fine.

So where is the evaporater installed and how do I get to this?

 

Dear Toon,
You know where the expansion vavle is fitted. Well move slightly forward of this and you will find the evaporator. It might be hard to see. You can get a better view if you go from underneath. Quite a bit of disassembly is required to get it out.
Ciao,
Adrian
964C4

 

This is the procedure for a 993, but according to the PET the 964 A/C arrangement appears to be identical. If something failed in here like a o-ring, fitting, evaporator, your leak check fluid would drain right behind and in the middle of the front tires. #18 in this picture is the evaporator, #15 is the expansion valve

Here is a picture of the heating / A/C system




Here is the procedure for getting into this area (there are diagrams, but I left them out for ease of posting) which is not an easy task.


870119 Removing and installing heater I air conditioning unit


Removal

1. Take off battery ground cable.

2. Draw off refrigerant with service equipment.

3. Remove fuel tank.

4. Remove cover of heater/ A/C unit (old version
is held in place by 2 bolts with washers,
new version is fitted with spring clamp).

5. Remove Central Electrical System.

6. Remove wiring harness cover.

7. Detach electrical connector from fan housing
cover and place Central Electrical System
on fender (use fender protectors).

8. Detach wire connector from blower
final stage.

9. Remove firewall

10. Remove fresh-air cleaner grille.

11. Undo fastening screws.

12. Disconnect air conditioning pipes from expansion
valve. Plug ports and piping immediately
with air-tight seals.

13. Pull off connector from pressure switch.

14. Detach NC piping bracket and move NC
piping out of the way.

15. Pull off condensation water and water drain
hoses (disconnect tie-wraps) and
push rubber grommets forward.

16. Remove radio, heater/ A/C regulator and
glove compartment. Pull off connector
above glove compartment.

17. Undo fastening bolt and nuts.

18. Remove side panel and pull off right and
left hot air induction flanges.

19. Pull off connector from servo motor for
temperature mixing valves.

20. Separate wiring harness from heater/ A/C
regulator (harness is tied to the passenger
compartment wiring harness) and pull
through to passenger side.

21. Start by removing heater/ A/C unit on righthand
side. Pull off air ducting to side
nozzles and pull wiring harness along.

Installation

1. Detach spring clamp of left and right heater!
A/C unit (new version).
911 Carrera (993) Air Conditioning

2. When re-installing, fit right-hand air guide
before heater/ A/C unit is brought into installation
position (for better accessibility). The
left-hand air guide can be pushed in place
with the heater/ A/C unit fitted after the large
instrument cluster has been removed.

3. Replace a-ring for refrigerant pipes at expansion
valve and coat lightly with refrigerant
oil.
Note
Be sure to top up with refrigerant oil when
replacing the heater/ NC unit or the evaporator.
Determine refrigerant oil volume and refill
with refrigerant oil (volume drawn off + 30 cc).
Refrigerant oil drawn off from an NC system
that has already been operated must not be
reused.

 

Thanks Bob,

just did the procedure last week (well al least a part of it) when I replaced my LH front blower. If I hand only known then that I had an airco leak down there .....