Advise needed about air con re-gassing and oil top up

[larryseaman]

Hi all, I run a KZJ95 (1KZ-TE) Colorado/ Prado now on 260,000 miles in Zambia. When I imported it here almost 10 years ago from the UK I had the air-con re-gassed and until now it has been working wonderfully; not had to touch it once! Just recently it feels like at times it's not quite running as cold as it used to. Sometimes it seems cold and other times it seems just cool. Obviously, here in constant 30-35 degree heat I need it working well!

I was considering getting it topped up with the correct HFC 134a refrigerant but when I spoke to a guy here he suggested I also inject the correct oil (ND-OIL 8) at the same time as the gas to keep the air conditioning pump in tip-top shape. I never knew oil needed to be added and wasn't convinced of his explanation about adding it into the pipes while re-gassing.

Any thoughts please? I don't want to damage what has been a very faithful part of my vehicle until now and can't afford to replace the pump if anything goes wrong!

Thanks

 

[Ben Stratford]

I remember travelling from Lusaka to Kitwe in Dad’s Fiat 132 which had aircon. We weren’t allowed to open the windows because it was just about to cool the car. After 2 hours of arguing about it in 35 degrees he relented and windows were opened. Clearly the aircon wasn’t working.
I would suggest that the aircon seals have started weeping and the refrigerant is leaking out. So regarding whether you use oil or not may be a fruitless task. A pressure test first would be my suggestion which the regarding guys can do for you. Only regards if the system holds pressure.

 

[Dave]

In theory he will need to remove the existing gas, and weigh it. Then you will know how much (if any) has been lost, and decide if you have a leak, or just a bit of natural loss. When recovering the gas, some oil may come with it and this should be measured, and the same amount replaced when recharging.

 

[Towpack]

Any half decent air con specialist/regasser will remove the existing gas charge, do a pressure test and (if testing OK) regas. A full regas should contain the correct amount of compressor oil and usually a UV dye to facilitate identifying any future problems with leaks. I did a diy gas topup some years ago with a recharge can from Halfords and it worked, for a while but ended up taking it to a specialist in the end who identified a slow leak from the condensor.

 

[larryseaman]

I remember travelling from Lusaka to Kitwe in Dad’s Fiat 132 which had aircon. We weren’t allowed to open the windows because it was just about to cool the car. After 2 hours of arguing about it in 35 degrees he relented and windows were opened. Clearly the aircon wasn’t working.
I would suggest that the aircon seals have started weeping and the refrigerant is leaking out. So regarding whether you use oil or not may be a fruitless task. A pressure test first would be my suggestion which the regarding guys can do for you. Only regards if the system holds pressure.

Hi Ben, thanks for the little story, I do visit those cities lots and can imagine what it must have been like desperately hoping that the air-con would get cooler!
Is there a way that I can test for any leaks myself? If so I would prefer to do that as things can get a bit chaotic when using locals sometimes. 3 men and his dog all went to get involved!
Also, if there is no leak, would you still say it's normal practice to add the oil at the same time as the refrigerant?
Thanks

 

[Ben Stratford]

As per @Towpack and @Dave if you take it for a regas but ask them to pressure test first then you should know whether to proceed.
My compressor was found to be leaking so I have ordered a Toyota seal kit for it. Once the seals have been replaced I will call the regas guys and get it refilled with the gas / oil / dye and see how it goes.
I appreciate what it’s like over there with every man and his dog interested in giving advice

 

[Dave]

Depends how much gas comes out. If its a lot less than it should be, then you have a leak. They usually stick some dye (which contains oil) back in when charging. This may have been done on a previous occasion as well, so worth a look with a UV lamp.

 

[larryseaman]

In theory he will need to remove the existing gas, and weigh it. Then you will know how much (if any) has been lost, and decide if you have a leak, or just a bit of natural loss. When recovering the gas, some oil may come with it and this should be measured, and the same amount replaced when recharging.

Thanks for the advice. The guys here are quite the opposite to 'specialist' and I'm sure they won't be able to remove the gas and weigh it. I think the term 'cowboy' comes to mind! That's why I try by all means to do all the work on the Prado myself where possible. I've had far more successes this way. I've considered buying one of those re-gas/ seal/ UV light kits but I'm not sure if they can be shipped due to them being highly flammable and pressurised?

 

[Dave]

You domt want any sealants in there, can cause more problems.

 

[larryseaman]

You domt want any sealants in there, can cause more problems.

Thanks for the advice Dave, I'll avoid the sealants.