P505 Air Conditioning

[KIMDEB]

I have within the last 3 weeks had the airconditioning on my Series 2 GTI converted and re-gassed (R134). It had been unused for 3 years, due to the car being stored.

Within a fortnight of the re-gas, sufficient gas had leaked away to activate the pressure switch, and thus isolate the electrical circuit to the compressor.

The re-gas included the addition of a leak detector dye, and thus far, no evidence of a leak can be found. The thought at the moment is that it may be the evaporator. The evaporator drain tube, above the gearbox, appears to be dry, although the present cold, low moisture conditions would not be helping in the leak detection process.

When the car was on R12, no gas losses occured.

Has anyone removed an evaporator unit from a 505 before? The Haynes manual does not seem to address the airconditioning system, and I suspect that the job may be quite labour intensive, especially if the dash, instruments, ducting etc needs to be removed. I have replaced a Series 1 dash in the past, which was reasonably straight forward.

Cheers,
Kim.

 

[fiveohs]

The 505 is easier than many cars, because the evaporator comes out from the engine bay side. The hardest part is removing all that firewall insulation first, without destroying it.

Also with the GTI, the engine might get in the way of removing the stuff from the firewall. Yet another instance of how those particular engines just make these cars alot harder to work on than they should be.

Dave

<small>[ 27 June 2002, 10:38 AM: Message edited by: fiveohs ]</small>

 

[charles]

even if you could get the evap out from the engine side the gti is too close to the motor there is not enough room.could be wrong on that but the last one i had dramas with had to come out the inside.major time strip down,have plenty of time on you hands when you start.good luck.its pretty rare to have a evap leak,keep chasing outside,try another a/c guy he might have a different approach.pin hole in the condensor can be hard to trace due to the akward place.

 

[Chuck]

Greetings Kimdeb
Stop!!
The first move is to inspect joints and hoses for your AC system. Leaks usually occur 90 percent of the time from AC experts not following the Montreal Protocol. Parts of this Protocol insisted upon replacement of all system O Rings when retrofitting from R12 to R134a.
Due to the age of the vehicle you may expect pinholes in the condensor or anywhere else including gas leaks at the joins of rubber hose to metal fittings.
My suggestions are to purchase a TX Valve and replace every O Ring which means dismantle every pipe joint including the most difficult two pipes behin the TX Valve (19mm spanner) up on the firewall (don't be scared to bend up the metal overhanging the TX Valve to get the spanner on)
Let's just fix it!!
You can do this yourself - lubricate the O Rings using some AC oil or glycerine.
An air-conditioning guy can evacuate the system and do a vacuum leak - test for 15 mins - to establish a leak-proof system.
Good Luck!
Cheers
Chuck

 

[Chuck]

PS
Look for signs of oily residue around joints for your gas leaks including the compressor clutch and rubber hose to metal fitting.
Chuck

dance dance

 

[KIMDEB]

Thanks to everyone for your replies and suggestions. I had the system topped up again following the initial discovery of the gas loss, as a means of establishing the source of the leak.

Since then, the AC system has been operating OK, although I notice that the sight glass shows evidence of bubbles.

I think that it may be aged 'O' rings, which are perhaps becoming more supple with use. However, the suggestion to have replaced them during the gas conversion is valid.

I am driving to Adelaide this weekend, so I will top up again, and monitor the situation as the warmer months approach.

Thanks again.

Kim.

 

[Simon]

Just wondering if the leak is because the system was empty for three years and moisture has caused internal corrosion of the condenser or other alloy parts? Also it could be dried out seals in the compressor from lack of gas and lubrication.

Just wondering, don't you also have to change the "rubber" A/C hoses when going from R12 to R134? I seem to remember something about the new gas "leaking" through the R12 type hoses.

Simon

 

[KIMDEB]

Simon,
I am sure you are right. I think the initial loss of gas was due to dried 'O'Rings and compressor seals. The system remained sealed whilst in storage, but some minor corrosion may have occurred.

I had the "bubbles" re-checked, before departing for Adelaide. The sight glass was in fact showing traces of the mineral oil that is added during the conversion, so all seems OK for now. I used the system ooccasionally on the trip across, and it was cycling OK.

I do not think that the 505 Series 2 ducting and air flow is quite as efficient as the Series 1, but perhaps that is another point for discussion.

Cheers,
Kim.