Snake with good lung capacity behind dash!

I'll start at the beginning....

A/C wasn't blowing cold air...(not the blend motors)....low pressure pipe from the evaporator wasn't cold or covered in condensation. No book symbol on the HeVAC panel...everything appears to be ok.
So, a Re-gas then!!....I decided I'd go for the DIY 'in a can version' from Halfrauds.
The can came with a gauge so I'd know if pressures were right, connected as instructed to the low pressure line and I turned on the engine and set Climate to LO.
The gauge read green..low operating pressure (low refridgerant), as expected!
So I pressed the trigger for short bursts of a couple of seconds and watched the gauge..it gradually moved into the blue area . I decided that the halfway point would be about right in the blue segment (30 PSI) so continued squirting in refridgerant....the needle was almost there....pop!!

The needle dropped back into the green. Oh, balls!!! Got into the drivers seat and tested the output temp...tepid air!!
This is where the sound of hissing caught my ear....revved the engine and the hissing increased...turned the A/C off and the hissing stopped.

My own diagnosis is the evaporator had a pin hole leak...and pressurising the system just blew a hole in it. Or a seal has blown!! It must be a big one as the low pressure return has no pressure. The high pressure is still feeding...hence the hissing! Strange though that the HeVAC hasn't detected a evaporator temp error, or error...full stop!!

Criticisms and thoughts please....I personally think it's going to be expensive. I'll take a slap on the wrist for the DIY Re-gas!!!

if as you say it wur a weak spot in the evaporator then yer DIY kit wasn't to blame. I know of a few people on here that use DIY kits and they don't have any problems.
with a low charge in the system you can get a hissing noise from the expansion valve. this hissing does sound like a leak but it isn't.
you may have had some obstruction in the system which was shifted by the increase in pressure when you topped up.

what does the gauge read now?

slob said:

if as you say it wur a weak spot in the evaporator then yer DIY kit wasn't to blame. I know of a few people on here that use DIY kits and they don't have any problems.
with a low charge or even no charge in the system you can get a hissing noise from the expansion valve. this hissing does sound like a leak but it isn't.
you may have had some obstruction in the system which was shifted by the increase in pressure when you topped up.

what does the gauge read now?

Click to expand...

The low pressure side was reading nothing with the engine running. It went up to about 45PSI when the engine stopped!
So there might be a blockage?? Is the expansion valve in the cabin?? It doesn't make a hissing noise in the engine bay!
How do you get rid of the obstruction?

dunt know where the expansion valve is on your rangie but it should be near the evaporator,engine side of the bulkhead.
you will hear the hissing from inside just after you switch on the A/C.
if you have moisture in the system you could get a lump of ice which would cause a block. also if your condensor is blocked ( leaves,dead bugs and general crap) then that can cause weird readings on the gauges.
all of this is just stuff i've picked up while sorting me own A/C out. i'm no expert on it, just learning as i go along so i could be wrong on some things.

have you got leak detector in the system?

No leak detector...
condensor rad was changed about 6 months ago.
Wouldn't ice just melt if left long enough??

Would it be worth having it looked at properly?£££??

either wiat till a A/C eggspurt arrives on here or take it to a garage.
do you know if they changed the dryer at the same time as the condensor?

No they didn't...the blokes arm was well up his back to get the condensor done!! He had to change the blend motors and the HeVAC Panel as well.
And it had two re-gasses, as well!!

Fingers crossed for a blockage!! Or a forum aircon guru............

Still not fixed this yet!! There is still a hissing noise in the cabin but is it a leak???
If the system leaks out completely, doesn't the 'book o death' appear on the HeVac panel! Shouldn't the compressor clutch cut out to save the pump??

Could an obstruction cause the air to accelerate past it..creating an increase in noise... clutching at strays here!!!

Help!!

Aircon guru's where are you??

FORUM AIRCON GURU HERE!
i have no idea what your talking about?

im really sorry but i couldn't resist it. lol

gjb02storm said:

Still not fixed this yet!! There is still a hissing noise in the cabin but is it a leak???
If the system leaks out completely, doesn't the 'book o death' appear on the HeVac panel! Shouldn't the compressor clutch cut out to save the pump??

Could an obstruction cause the air to accelerate past it..creating an increase in noise... clutching at strays here!!!

Help!!

Aircon guru's where are you??

Click to expand...

if you have low enuff pressure in the sytem to affect performance ,then i would of thought the lp "low pressure"would be activated to prevent the compressor running and damaging itself ,if the charge is about right the large diameter pipe"suction line" running into the evaperator ,ie inside bit should be "sweating"ie condensation forming on it with the compressor engaged a hissing or gurgling sound is often normal at the expansion vale as thats where the compressed liquid from the condensor is changing state to a gas again using the heat from the cabin to revaporize,not sure thats much help but without having suction and discharge pressures on a guage manifold its hard to say .....sorry

Low pressure side has no condensation on the pipe at all. Both pipes from the bulkhead (from the evaporator) are warm to the touch. The hissing only started after I tried to recharge the system with a can from Halfords!

As you say low pressure should trigger a response from the system...turning off the compressor..showing the book symbol on the display.

Any more ideas...


Cheers for the windup Redrange!!!

sounds to me like its still a bit short of gas ,but without guages on the system i cant tell exactly whts going on inside,,,,,,,,,