Hi,
Anyone help me out with an air con regassing issue.
Friend lent me a STP refill kit as my A/C in my new car isn't working.
When I connect the gauge with the air con off the needle is in the red.
However with the engine and air con on the needle drops to zero.
Before I start to fill the system am I right in thinking that the pressure being high with everything off is correct and then the pressure drops with the engine and air con on as the system will try to equalize the high and low sides of the air con system.
And the fact mine drops to zero just means the system is very low on gas.
Cheers
Po

[Edited on 20/8/21 by po79]

I no little about AC systems other than having taken a couple of cars to garages to have the systems re-charged.

If the car is brand new I'd be heading straight bak to the dealer for them to sort it. It must be under waranty.

If purchased from a trader is it covered by them and can you go back to them.

Other than that I'd be heading to a garage to have the system fault checked (repaired if necessary) and re-charged.

Hi Nick,
No not new just new to me. It's a 2008 bought privately.
I got done the last time I used a local garage door a recharge so when I was given this kit to use thought I'd give it a go
But just want to check that the static pressure is always high until the system starts and then it lowers as the compressor pumps the gas into the high pressure side.
Cheers Po.

AC isn't my area really but... Is the gauge attached to the high or low side? What pressure is it reading? I assume low but haven't seen/used one of the aerosol (I assume) kits for years so can't remember
Low side will read high when engine/ac is off and come down when running.

Thanks adithorp,
That's what I suspected.
My mate bought the bottle and gauge years ago and never used it so he wasn't sure.
I'll to the system up this afternoon and post back.
Hopefully the system isn't too low and the one bottle will be enough to top it up.
Cheers,
Po.

Hi guys,
Just some feedback, it if helps.

The static reading( engine off or a/c off) was 125psi approx.

Engine and a/c running the pressure dropped to 0psi.

Topped the system up and it took a full can and added enough pressure into the system for the a/c to work.

However it's not quite enough to fully pressurize the system so will need to buy another bottle just to get it into the green.

So thanks guys all is well.

Po.