Replace air con condensors [ release any residual pressure

On my 996 C4, I need to replace both my condensers and radiators after 20 years of good service. There is seepage from the condenser, but there could still be pressure in the lines. How do I safely release any residual pressure before i disconnect the condensers? The car is already on stands and what was needed to be removed to get to the condensers and radiator is complete so the car is going nowhere now, Need some advise how to release any pressure. thanks!

What do you mean by safely? Not damaging the environment or not damaging yourself? You should get a specialist round to drain the system.......or take the caps off the inlet valves and press the pins down in the middle to pump toxic gas out (like how you let a tyre down but more dangerous). Ps. The 2nd option is highly illegal.

Hi, its unlikely there will be any pressure in the system. if there is they are intact, you would need to go to a garage with a a/c service centre and they will remove the refrigerant for you. This complies with the law. When did the System last work?? Cheers

air conditioning condenser - release presssure Hi, thanks for the quick reply, aircond didn't really stop working, I just took advantage of lockdown and started bumper to bumper maintenance, got to the radiators and saw the leak, so there maybe pressure left, car is on blocks with may missing items to prevent driving - so I'm in a bit of a pickle to take to a shop at this time, is there a safe way to test if there is pressure left? when I say safely, I mean me primary, but environment important too, athough I doubt there is much gas anyway. here is pic of what I found,

if the system is still cold and working, that means you have enough refrigerant in the system for the pressure switch to allow the compressor to engage. If the system is leaking it will dispense its contents in about 30 secs, if you have a hole in the condenser(which is common) due to rotting out, it will lose the contents quickly. From looking at your pic, it could look like they are wet due to the debris between the rads? possibly not wet from leaking?? If its still blowing cold then i definitely recommend you take it to a garage to have the remaining contents removed and then swap the condensers. Its against the law for you to deliberately release refrigerant into the atmosphere. If they have never been renewed, then its highly unlikely they will still have refrigerant? Let me know how you get on

yes agree, will keep the condensers intact for now, replace all around it and then take to shop to Degas and fit new ones. thx

If the clutch is engaging on the compressor there's pressure in the system.

Clean, including the radiator behind the condenser, and reassemble everything. You can then check some weeks later if there are visible leaks. Mine had clear patches of green refridgerant on them when they went last summer.

Hi Alex, as per my running thread, I am not sure about taking this job on. I was going to post a question about what happens if I switch the engine on to move the car when apart - would you recommend that or is it even possible please?

Not quite sure what you mean by 'apart'? If you've taken the condensors off, there is no gas. You can still run the engine, even with the AC on as the pump shouldn't run. There are plenty of people here who run cars with failed AC systems and no gas.

Hi Mike, by apart, I meant bumpers off and at least condensers off. When I am in there, I am going to check the rads. The thought is take everything off and drive the car back in the garage, get parts and re-assemble at a later date.

That shouldn't cause you any issues, i would order a drier and have the system vacuumed to boil of any moisture. Like said by a few is that the compressor shouldn't kick in if there is no refrigerant.

A lad down the road has just done similar with a Boxster, he needed his wife's car re gassing so got a mobile guy in a van out and had his system vacuumed at the same time, two days later he cane back to re fill and he gave him some pag oil to lube the O rings for install. He also changed the drier.

thanks, that sounds likes the perfect option! I'll look for that in my area

Others beat me to it but that should be straightforward. I agree with the comment about the drier and you'll find AC parts are readily available from various suppliers at good prices. Check the resistors for the fans, they're fairly easy to change while you're there, use cheap Chinese replacements (there's a thread on here somewhere). Delivery will take a little while from China.