Air Conditioning

[clivvy]

ok, so this is a general air conditioning question, as its for my Mazda. Last week, I had my Air Con re gassed/servcied etc after not being used for probably 5 years. System worked perfect, but it feels liek its not as cold now, after a week. I can verify there are no leaks, and the system is wokring as in the compressor comes on, I can see the flow of liquid, revs rise etc etc but the air coming out only feels cool now.

is there any thing I can check? Is it possible that because the system hasnt been used in such a long time, it may now need extra gas (like topping up the cooling system in a car?)??

hope you can help, im a complete novice when it comes to air con, ive never had it up until last week, so dont really fully understand how it works, or what to expect (other than very cold air!)

thanks!!

 

[Thomas-the-Terrano2]

watching with interest as ours i suspect needs regassing, its cold
or outdoor rammed air temp but not icy like last so fitted car was.

will do once know got engine cooling sorted, mind i do know the
aircon rad fan works as kicks in when car is trying to overheat.

also now know got an aircon rad in from of engine rad

 

[macabethiel]

Did you have it done at a Mazda dealer ? If not then you may not have fully optimised the system. Most modern cars will have a hook up to the ondoard diagnostics that ensure all the controls are set properly plus ensuring the right amount of refridgerant is put back into the system.

On a Mercedes the refridgerant is removed and the volume / weight is measured and the correct amount for that chassis number specific model is replaced.

At the dealership where I work we regularly get customers who have spent £50 at an Autocentre type establishment and they then pay another £75 to have us do the job properly.

If the vehicle has not been used for some time the seals will have dried out and you will have lost some as the system starts to work again.

There might even be a problem with the evaporator due to standing and that can be expensive to replace. I would take it back and get them to re-gas it and hope it OK next time around.

I had an old Merc C250 TD and I had mine re-gassed twice in as many weeks and it kept working until I sold it 18 months later. Often small leaks are difficult to detect even with the dye they use - hope this helps.

 

[clivvy]

I got a mobile chap to come out. he did everythign correct-serviced/cleaned and gassed/dyed. cant see any leaks, so seals must be solid. System is functioning, just not icy cold...on a day like today, you can really tell...

 

[solarman216]

When you say it is not leaking How do you know this??:nenau:nenau Rick

 

[clivvy]

he put green dye in, and i cant see any dye anywhere in the engine bay or where the evaporator is (might need to re check evaporator though), isnt this correct, I should see green dye if there is a leak?

what part of the system could be failing, if the air isnt cold enough??

 

[clivvy]

ok guys, still hoping you can help. just been out to do some diagnostics. this is how the system currently operates-turn on A/C, the relay clicks, both rad fans coem on and STAY on, revs do rise, but sometimes over 1k, sometimes just 800, and stays there unless you turn A/C off/on again. air coming in isnt cold at all. I can hear a sound from under the glove box, this wasnt apparent when the system was working, but became apparent the other day, when the air wasnt chilled any more. I can see gas in the inspection hole in the accumulator in fron tof the rad (if thats what it is called?) and this stops flwoing when I turn off the A/C.

Air does come into the cabin, but its not ice cold, at best, its cool, but its hard to tell if its just air from outside, or partially cooled air, im going to assume its just air from outside. When I turn off the A/C you can hear the noise from under the glove box like something whirring to a standstill, perhaps whirring is the wrong word, alomst like water flow ceasing, the normal sound you hear from air con units!

I checked the white plug that connects the system, one contact was corroded, so cleaned that and refitted, same issue, then I wanted to check the relay near the washer bottle, but I dont know which one it is, i checked the top one of the three, and it seems ok. I checked the fuse and relay in the fuse box, that seems ok too. im lost!

helps!

 

[briggie]

ok guys, still hoping you can help. just been out to do some diagnostics. this is how the system currently operates-turn on A/C, the relay clicks, both rad fans coem on and STAY on, revs do rise, but sometimes over 1k, sometimes just 800, and stays there unless you turn A/C off/on again. air coming in isnt cold at all. I can hear a sound from under the glove box, this wasnt apparent when the system was working, but became apparent the other day, when the air wasnt chilled any more. I can see gas in the inspection hole in the accumulator in fron tof the rad (if thats what it is called?) and this stops flwoing when I turn off the A/C.

Air does come into the cabin, but its not ice cold, at best, its cool, but its hard to tell if its just air from outside, or partially cooled air, im going to assume its just air from outside. When I turn off the A/C you can hear the noise from under the glove box like something whirring to a standstill, perhaps whirring is the wrong word, alomst like water flow ceasing, the normal sound you hear from air con units!

I checked the white plug that connects the system, one contact was corroded, so cleaned that and refitted, same issue, then I wanted to check the relay near the washer bottle, but I dont know which one it is, i checked the top one of the three, and it seems ok. I checked the fuse and relay in the fuse box, that seems ok too. im lost!

helps!

silly question , but , is your recirculation button pressed ? ..... you are describing exactly the same noise / symptoms as when i press the recirculation button ...ideally the vents should be switched as up and not towards the feet .... centre vents will feel cold , but not maybe immediately .... give it a minute or so

 

[clivvy]

ive tried that plus everything else, was working fine up untill Thursday...

 

[jims-terrano]

Get the mobile chap out again to check his work, must have have some kind of guarantee surely?

I had T2 regassed at Kwik Fit two years ago, before this it got cool and I could here a kind of hiss whilst compressor was on. After regas hiss had gone and it was very cold. Now after two years the hiss is back and it only gets cool. May be I'll treat it to another dose of Kwik Fit gas.

Jim

 

[clivvy]

Get the mobile chap out again to check his work, must have have some kind of guarantee surely?

I had T2 regassed at Kwik Fit two years ago, before this it got cool and I could here a kind of hiss whilst compressor was on. After regas hiss had gone and it was very cold. Now after two years the hiss is back and it only gets cool. May be I'll treat it to another dose of Kwik Fit gas.

Jim

you know Jim, I do wander if it is as simple as it needs gas. i do know the system will eventually shut down if there isnt enough gas or pressure, so it could be that due to length of time without gas, ive lost the gas i had, or there isnt enough left in the system... i wonder if its worth trying a recharge kit from Halfrods?

 

[briggie]

you know Jim, I do wander if it is as simple as it needs gas. i do know the system will eventually shut down if there isnt enough gas or pressure, so it could be that due to length of time without gas, ive lost the gas i had, or there isnt enough left in the system... i wonder if its worth trying a recharge kit from Halfrods?

i had mine regassed .... it has gas and oil .... seems it needs oil too

 

[clivvy]

but on the flip side, i only had it gassed last week. didnt take the guy long, no reason to believe he didnt do a good job, no reason to believ he didnt put correct amount of gas in-he had the chart etc and it stated something like "700", whatever that means...

 

[clivvy]

not sure if i had the PAG oil filled or not, but everythign is functioning, no oil or lack of oil would mean the compressor not working?

 

[briggie]

not sure if i had the PAG oil filled or not, but everythign is functioning, no oil or lack of oil would mean the compressor not working?

no harm in ringing him up and asking his advice clive ....... last week in norfolk the temps were around 29 / 31 degrees c ..... but even then i could only have my aircon on for a max of 20 mins because my arms started to grow icycles holding the sterring wheel :lol

 

[solarman216]

I have had lots of cars with dye in them that continually leak over a period of a few months and have never seen any dye on the out side, this dye by the way is flourescent and can be see much better with tinted gogles and ultra violet light, but still never seen it, I have currently two commercial freezers that leak over a 3 month period and have put dye in them, nothing ever seen, and do not worry about oil, if that has leaked out, like any oil it makes a mess, and can be seen fairly well, and of course will be your gas leak as well, but in my experience very rare, Rick

 

[clivvy]

hmm..shouldnt i be able to see the green dye, if there is a leak?? I can see what was spilled when it was filled, is it not the same if it leaks? If I can get this fixed within the next two weeks fairly cheaply, I will, but would be nice to fix it myself, is there a leak-sealer you can buy??

 

[solarman216]

Yes there are leak sealers but again I have not found one that works, and they are expensive, in theory you should see green dye at the leak, the only one I ever saw the dye, was on a fair leak, that if I had had good hearing I would have heard anyway, the best leak detector I am told is the one that works on ultrasonics and can hear a leak even at considerable distances and extremley small leaks as well, they quoat micro grams per month (that is small) your motor contains around 700 grams of gas (in its liquid form) but they are way too expensive for me, Rick

 

[CHASTER]

Air conditioning.

My T2 a/c was not working. Saw a green dye leak on HP pipe which runs along top of rad. Managed to cure it with ally sleeving and took car to Kwikfit for a regass. Lasted a few days but had to take it back and get refund.
Found that they do leak tests by watching if vacuum holds for about 10 mins or so. Not much good on these trucks because the HP pipes have several rubber anti-chaffe sleeves. The vacuum just sucks the sleeves onto any holes and seals them. It's a different story when the same pipes are under working pressure (200 psi or so). My repair was OK but the pipework under the sleeves was corroded.

Had to go to Nissan for a new section with the service point on it.

We will now have two minutes silence for my wallet.

Bought a load of guages, gas etc from Autocool and made a vacuum pump out of old parts from my garage "stock".
Pulled the system down to 28 in HG and left it there for a couple of days to dry out.
Gassed up as per normal proceedures, compressor pulled in at 28PSI. Stuck 700grams of R134a with oil and was delighted to see HP rise to 200.
Wow; is it chilly now. Has been OK for a week now but the sun has b---ered off. Anyway-----the demisting is now instant and we might have an Indian summer.

 

[ssteve]

usualy fill system with nitrogen to test for leaks, how do you find a leak by applying vacuum
to the system??????