156 A/C - basic questions

[Citroënbender]

They're not serviced as a spare part by Sanden but are all over third party sales sites.

eg: http://latticetech.com/control_valves/control_valve_ltcv02.html

On the four pot 932 series, there is frequently chafing to one refrigerant hose on the fan shroud edge. It's enough to cause the gas to leak.

[poohbah]

Cheers CB.

I'll have a poke around from the ground and see if I can see any chafed hose.

Probably the most sensible thing to do is swing by the workshop and see if I can get a pressure check and quick diagnosis.

[bazzbazz]

The item you have circled in the V6 pic is the power steering pulley. The A/C compressor is the unit & pulley below the one you circled.

The most common cause of slow leaks other than physical damage are faulty/dried/perished connector seals/O-Rings.

I would suggest that as you have most likely lost gas over a short period of time that you have a leaking seal somewhere. In this instance, as I am a mobile service and am limited to how much equipment I can carry, I recommend clients take the car to a A/C Service Center that just specializes in A/C. They have the ability to pressure test the system with nitrogen and will find the leak quickly, its what they do.

Otherwise, without the specialist tools/equipment you can be chasing your tail, in both time & money.

[poohbah]

Cheers bazz.

[poohbah]

Jacked her up this arvo and had a good poke around. Compressor clutch is definitely engaging, and couldn't see any obvious chafed hosing, or anything obvious amiss really. Nothing left to do now but seek professional diagnosis ...

[Citroënbender]

Good work eyeing it up first though. The other cheap fun tool is a UV torch and appropriate safety goggles often sold together as a kit.

[poohbah]

Good tip CB. Might pick one up next time I'm at supercheap.

[Citroënbender]

Any progress?

Now you've got a nice new screen you can get the AC icy cold - so when it sallies forth out the demister vents, your glass cracks all across the bottom...

[poohbah]

Not yet - have parked that issue for the moment as I just had to spend a fair wad on the GTV (full service, wheel bolts and new tyres).

Will get around to it when I've had a break from spending!

[bazzbazz]

Will get around to it when I've had a break from spending!

Like that's gonna happen . . . . 

[Citroënbender]

Was that "window cut" your experimentation to see if the TXV could be replaced in-situ?

I note the 147 and facelift 156 seem to share expansion valves (by part number) and quite possibly evaporators - with just slight differences in the intermediate tubing from valve to firewall junction. 

When you look at the regs for a warrantable replacement of a Sanden compressor, it does indeed make the process seem unviable as they deem modern evaporators to be unsuited for flushing - and therefore must be replaced... 

Unrelated/related overall:

To date I haven't seen any stuff on the internet for testing of the compressor's internal control valve (mechanical type) - whether the rating is a simple "cracking pressure" like an old diesel injector or when it is fully open (or if there is any meaningful difference between these two points).  I'd like to know because the pressures are quite small and it would be easy/fun to build a simple tester.  There is informed commentary from some sources saying the valves are more often than not the root of a "tired" SD7V16 compressor per gauges, but it would be nice to have the ability to discern if/when this is actually the case. 

[poohbah]

f you want to know where the expansion valve or TX valve is on a 156 JTS

Is it the same in a Series 1 V6?