Replacing A/C Fittings

[MK802]

I have been working on my ’91 S2 with an a/c problem. With the system emptied of refrigerant, it wouldn’t hold a vacuum which means I have a leak somewhere so I’ve been systematically changing all the seals at all the hose/pipe connection points in the system and have a question: Does anybody out there know how to get to the fittings between the evaporator coil/expansion valve where they pass through the firewall from the engine compartment? It almost looks like the engine has to come out as ridiculous as that seems. Anybody out there ever done this?

Thanks

[Zero10]

It is _SUPER_ tight. You can drop the engine an inch or two by un-doing the steering shaft and lowering the crossmember. This should give you enough room to get at the bolts. If this doesn't, disconnect the rad hoses and drop a bit further. If this won't go, then you are stuck.

That said, I would be tempted to put a small amount of refrigerant in the system then use a sniffer to hunt down the leaks. I have never seen those fittings leak before, and they sure aren't a common source of failure. The fittings in question are to the evaporator, the expansion valve is mounted up top, under the blower motor IIRC.

[mattdavis11]

Put some air or nitrogen in the system and use a spray bottle filled with soapy water if you want to find the leaks. 100 PSI should be enough. I too have never heard of a leak on our car in that location. Schrader valves are known to be the most common source for a leak. Take a good look at your compressor, if it is covered from front to back in black, grimey, oily residue, there is almost 100% chance that the front seal on the compressor has blown.

[Zero10]

More common than the front seal failing is the 4 O-rings ontop of the compressor under the manifold plate failing. When they fail the oil runs all over the compressor and it looks exactly like a front seal failure, but the advantage is this costs about $6 and takes 20 minutes to fix.

If you don't have a sniffer then use mattdavis' method, I'll repeat again, I have never seen those fittings leak before.

[TJFORGUE]

I had a leak on my S2 on the tube that's by the firewall. Use nitrogen or refrigerant to leak check, air will put moisture into the system that will cause more problems.