RangeRovers.net Forum banner

1 - 16 of 16 Posts

·
Registered
1995-2002 Range Rover P38A
Joined
·
292 Posts
Discussion Starter #1 (Edited)
Pressing the pins on the valves in the AC lines - both high and low - resulted in a tiny puff, then nothing. All the gas is gone, it seems.

Where would I look for a leak, or do I call Mr AC man to put dye in the system? I've never worked on any AC systems.

Thanks - Tom
 

·
Registered
Joined
·
978 Posts
Here in the US, it's possible to buy a refrigerant canister with dye that reacts to UV light relatively easily. Through an outlet like Amazon, it's also possible to just buy just the HVAC dye that you can add to the refrigerant line. For this repair, however, it might be better off to have the pros handle the repair. There's usually a strict refrigerant recovery protocol that you're supposed to follow. The process also requires a few specialized equipment to do correctly. Better yet, maybe the best option is to locate the leak yourself, repair the leak yourself, then have the pros handle the refrigerant charging.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
218 Posts
Tom, take it to the AC man, otherwise you will send months chasing your tail, and it will cost a lot more in the end than having an expert look at it. Usually $100 to $150 will see it done at a reputable shop. Now is a good time as they will start to get very busy soon.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
292 Posts
Discussion Starter #4
I should add this - in the last week or so, I have been noticing a somewhat damp, slightly rotten smell in the cabin. Does this seem to indicate the gas leaking out through the evaporator - in the heater box? If so, brilliant. I can't wait to remove the dash AGAIN. Theo and Dt, yes, I will find and repair the leak if I can, then get it recharged.
 

·
Registered
Joined
·
978 Posts
Refrigerant doesn't smell anything like something rotting. Most likely, the smell is due to abnormality with refrigerant charge causing excessive condensation over the surface of the evaporator.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
292 Posts
Discussion Starter #6
I've booked the man to find the leak tomorrow. I suspect it's a crack somewhere as there was nothing in the system at all.

thanks
 

·
Super Moderator
Joined
·
2,428 Posts
It will almost certainly be leaking from the top corner of the condenser (left side as you look at it, RH side of the car). There's a foam pad that sits on it and eventually allows it to corrode in that corner. If you take the slam panel off, you'll be able to see traces of the PAG oil where it has come out with the refrigerant. Correct way to trace a leak is to pressurise the system with Oxygen Free Nitrogen at 10 bar and with a length of tube as a stethoscope you'll be able to hear it leaking. The canisters you can buy are only to top up a system that is a bit low and usually only contain around 300 grams of R134a, a 2000 P38 takes 1380 grams. The smell would have been due to it still working but with a low charge.
 
  • Like
Reactions: Dtoyne

·
Registered
1995-2002 Range Rover P38A
Joined
·
292 Posts
Discussion Starter #8
Good.

Better that than the evaporator!

AC man is here right now. I'll know in a minute, hopefully.

Climate change anyone? I am not going an Australian summer with no AC...
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
499 Posts
Come to Tassie then , AC is not the button to be pushing in this part of Australia?:LOL:
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
292 Posts
Discussion Starter #11
The answer is... all working now. I'm reluctant these days to farm any work out to anyone except a trusted group of two. Most mechanics today simply do not know how to diagnose faults properly.

The AC company sent a top guy out - he tested the system for leaks thoroughly, evacuated what was left of the old gas, did a negative pressure test, poked everywhere and could not find any leaks. He showed me the gauges holding pressure.

We regassed and it's all working. Could it all have leaked out over time then finally have given up? In hindsight I think it's not been cooling as well as in past years. I've had it on, but on heat mostly during our winter. I have no idea when it was last regassed. Never by me in four years.

I learned something about the HEVAC unit in this. When you first start the car, the AC comp cuts in after a few seconds, if it's all working. Then, after two minutes and 13 seconds - yes, I timed it twice - the HEVAC checks that the AC comp is pumping - via the tripartite switch probably (not via the AC relay - I don't have one as I have a pre-99 HEVAC panel in a 2000 car with a jumper where the relay used to be).

If the comp is not running, it throws the book on the HEVAC.

So if you're getting the book symbol after that time period, it's telling you that it's finding the AC compressor not working.

*

And after five minutes exactly, it polls the temperature sensor on the heater pipe. If it finds that sensor open circuit, it will throw the book.

*

Should I remove my slam panel and inspect where the foam pad sits on the condenser?

Thanks.......Tom
 

·
Super Moderator
Joined
·
2,428 Posts
Could it all have leaked out over time then finally have given up?
Quite possibly. Slow leaks are usually the O rings where the hoses join the compressor or the hoses themselves. A vacuum test will show a leak if left long enough but isn't as effective as a pressure test with Nitrogen. Or just that the hole in the corner of the condenser is only a pinhole at the moment.....
Should I remove my slam panel and inspect where the foam pad sits on the condenser?
Probably not a good idea. If the foam has stuck to the alloy of the condenser, you could turn a minuscule leak into a bigger one when you take it off.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
292 Posts
Discussion Starter #13
I better leave it then for now. He did do a pressure test too - no leaks evident. If it lasts for another few years then I'll consider that a result...
 

·
Registered
2006-2009 Range Rover MkIII / L322
Joined
·
4 Posts
Here in the US, it's possible to buy a refrigerant canister with dye that reacts to UV light relatively easily. Through an outlet like Amazon, it's also possible to just buy just the HVAC dye that you can add to the refrigerant line. For this repair, however, it might be better off to have the pros handle the repair. There's usually a strict refrigerant recovery protocol that you're supposed to follow. The process also requires a few specialized equipment to do correctly. Better yet, maybe the best option is to locate the leak yourself, repair the leak yourself, then have the pros handle the refrigerant charging.
I am getting ready to recharge the AC in my 2007 RRS SC, i cannot find any PAG ND8 oil, however I read that PAG 47 will work. Does anyone know how much oil to add ?
John
 

·
Super Moderator
Joined
·
2,428 Posts
It's in the workshop manual for a P38, so would think it would be in the workshop manual for an RRS too. You might have better luck asking on the L320 forum than here.
 

·
Registered
Joined
·
3 Posts
Pressing the pins on the valves in the AC lines - both high and low - resulted in a tiny puff, then nothing. All the gas is gone, it seems.

Where would I look for a leak, or do I call Mr AC man to put dye in the system? I've never worked on any AC systems.

Thanks - Tom
Pressing the pins on the valves in the AC lines - both high and low - resulted in a tiny puff, then nothing. All the gas is gone, it seems.

Where would I look for a leak, or do I call Mr AC man to put dye in the system? I've never worked on any AC systems.

Thanks - Tom
Often it is corrosion on the top of the receiver dryer causing a leak
 
1 - 16 of 16 Posts
Top