Aircon issues

[riverstyx]

Hi All,

I'm in the process of repairing the front end of our '97 A4 1.9TDi 110 after my girlfriend had a little accident in the snow before Christmas. One of the items that was damaged is the air-con condenser but I'd like some input before I decide on whether to replace it...

Basically, the aircon didn't work properly before the accident:-

I did get kwik-fit to empty and refill the system as I though it might have been low on refrigerant, but they ended up refunding me as a) I couldn't feel any noticeable improvement, and b) the printer on their machine was not working so they couldn't verify whether it had met the "10% improvement or your money back" criteria that they advertise.

A scan of the aircon ECU revealed no fault codes, the compressor clutch would engage and the compressor ran so it isn't siezed, and the condenser would get warm, but there seemed to be no noticeable cooling effect in the cabin. The two metal pipes that run down the right hand side of the engine bay would get warm and cool respectively but not hot and cold as I have observed on previous vehicles I have owned.

I'm really looking for any suggestions as to what the fault might be as I am reluctant to spend money replacing the now punctured condenser unless I stand a reasonable chance of fixing the pre-existing fault.

In addition whilst trying to remove the damaged condenser I have stripped the thread of the compression nut on the end of one hose and have still not managed to remove the other hose at all. They were both well and truly seized and even the liberal application of penetrating oil followed by the plenty of heat, cold, heat, cold routine did nothing to loosen them up.

The pipes seem to be constructed as one part with crimped joints between rubber and metal sections - if I cut the damaged compression fitting from the end of each rubber hose does anyone know whether an air-con specialist would be able to crimp on new ends?

Apologies for the long post, and thanks in advance for any info...

 

[aragorn]

Theres a few things that would cause poor performance, the most likely on an old system is the drier, which is a metal can mounted just beside the compressor. These only have a finite life and just wear out. The orifice pipe may also be blocked up.

The pipes almost ALWAYS sieze solid onto the alloy parts, and trying to remove them will only result in things breaking.

I have to say i kinda doubt an AC specialist would have the equipment to crimp on new fittings, and they'd likely just recommend getting a new pipe. New pipe might be a good thing though, because it allows you to change the orifice pipe, one of the other possibilities for a poor performing system.

In effect your going to need a new condensor, a new drier, some new pipes (unless your VERY lucky and manage to find a good used set that havent siezed on) then a full regas/oil.

I just ripped it all out of the Shed, especially as my compressor was siezed. Presumably in a similar manner to you my system had been damaged some sort of collison, and was then badly repaired. They'd completely mangled the fittings trying to unbolt the condensor, snapped the pipes off the condensor end tanks then chemical metaled them back on!

 

[riverstyx]

Thanks aragorn for your very comprehensive reply.

It looks like the only part that is a real pain to replace is the evaporator. The system didn't appear to be leaking before the condenser was punctured so assuming these are not prone to blockage I'd assume that it is probably ok.

I'd be looking to replace the dryer anyway given the system has now been opened to the atmosphere as even if it had been ok before its likely it is now full of moisture.

I think I will replace the parts you suggested and see how things go from there.

Thanks again...