Diy Aircon Top-up

[johnb80]

mmm...interesting......

 

 

might be cheaper here

 

 

How do you think I would fare attempting a top up a non-working (3 years now) system?

The real danger here is that if all of the gas is gone i.e. no pressure left then air can be in the system. If air is in there, so is moisture and it will need to be vacuumed (no, not with a hoover or Dyson) with a vac pump. The drop in pressure causes the water to boil and the air gets removed too which reduces the performance of the refrigerant.

 

I don't wish to rain on anybodys parade, the top ups work but are exactly that - top ups. One minor point, when filling a vehicle system you should NOT have it on recirc, you want the system to be working as hard as possible to reduce the pressure in the LP line which makes filling easier and quicker.

 

Regards - JB

[Masked Marauder]

Yes I agree, it is not a substitute for a service and a system that has not worked for a few years is unlikely to be resurected by it.

 

But if you pressure test and there is positve pressure on the suction side with the air con running then it is quite possible that there is no leaks and the top-up may well work for you.

 

As for the recircled air setting, I was just following orders...... Well instructions anyway!

[Guest JohnP]

Thanks for all the info, guys - kit is on order (forgot to get the tester!) and will add comments when I have gone through this procedure. No A/C problems, just not getting as cool as last year (and summer is warming up!)

John

[johnb80]

Yes I agree, it is not a substitute for a service and a system that has not worked for a few years is unlikely to be resurected by it.

 

But if you pressure test and there is positve pressure on the suction side with the air con running then it is quite possible that there is no leaks and the top-up may well work for you.

 

As for the recircled air setting, I was just following orders...... Well instructions anyway!

Totally agree with you !

[johnb80]

Accepting that all cars leak gas via the seal on the compressor shaft and other places, it amazes me that car manufacturers dont put a decent size reservoir in the system i.e. a bit like one of these top up bottles permanently connected.

 

Regards - JB

[GSMGuy]

John P, please post your results... I have an apparently fully functional system, just doesn't seem to get as cold as I'd like, got 10 degrees in the vents with an outside 20 or so, with an expensive Fluke temp gauge and air probe.. Car is 3 years old, 50k so possibly may have lost a little... On another subject, sort of... Has anyone tried the "ice cold" top up available on one of the given links? Claims to reduce the air temp by another 15 degrees....

 

I had an a/c service done on a 406 Exec TD I had about 5 years ago, and the told me they had added a "booster" to the a/c It was great!! I could breathe towards the centre vents and get mist on my breath, if I had the vents on my hands too long I used to get numb fingers!!! Bloody proper aircon...

 

Mike

[Guest andypenn]

Hi All

My Air con was having trouble with cooling today so am V interested in this thread, I have looked on Ebay and on that Autokool site but the pressure tester does not seem to be available at the mo :( , So this is the question does the tester test pressure or vacuum, what pressure/vacuum does the tester read for instance MM says that his Air con tested at 8psi when he started and it took a while to get into the GREEN what pressure does the GREEN start and finnish can you be more elaberate, there is a pressure gauge on the AUTOKOOL site but this has the wrong fitting could you use thi with a coupling hose ? and last but not lease on the newer GAL wher is the low pressure port you discribe.

 

Cheers Andy.

[Masked Marauder]

You measure the suction side of the air con with the air con running. It is better refered to as the "Low Pressure" side.

 

The guide says that you should have between 22 and 44psi on the gauge, that is at normal UK type temperatures!

 

The gauge just presses on to the low pressure connector.

 

The guage on the site is a replacement for the ones on hose sets, you would also need a suitable hose connected to it.

[Guest andypenn]

Hi MM

So could I just push on a tyre pressure gauge? :(

Andy

[Masked Marauder]

Wellllllllll, tbh Mine was not working because the adapter for it would not push the valve down, so I used mine on my tyre to test it and it went up to 44psi. Which is the pressure in the front tyre...

 

And with the adapter off it looks a lot like a tyre pressure gauge.....

 

And as long as the tyre pressure gauge goes high enough, and you can get a good enough seal......

 

May well be worth a try....

 

But remember, low side only, engine running, air con on. I think on your model it is near the compressor, the high side is to the left of the battery box and has a black cap on it and is bigger than the low side.

[Guest JohnP]

I asked about the gauge and got this reply:

 

Unfortunately I sold the last one tonight. The gauge was only to be used as a very rough guide the only way of telling how much refrigerant is in your car is by weighing it.

 

If you think your system is empty then you can charge to the full capacity in weight which is usually indicated on a sticker on the front slam panel. If your car has something in but is not getting cool enough then I would start with one can and see how it is after this.

Hope this helps.

 

This confirms the views on the thread - get an expert to do it properly but if you're just topping up, with a little bit of care, you should be able to improve things. I still haven't received the topup kit - will advise as soon as I get cracking...

[Masked Marauder]

Well if your keen to use a gauge John and your over my way, just ask!

[Guest andypenn]

Hi All

Well recieved my kit today emptyed the leak sealer and dye can into the system to try and identify if I have a leak, then used a hole can off gas after which I had a loverly cold air stream from my vents loverly jubly

:) :) :)

 

Will have to see how long it lasts.

 

Cheers All

 

Andy.

[GSMGuy]

Slightly off topic, but mine has gone in to get the 'box swapped again today.. Saw them regassing a car in there - I wasn't aware they did A/C.. Anyway few little hints dropped, and after finishing my box tomorrow, he is going to empty, vac, flush and refil with new gas and oil.. All FOC as a goodwill gesture :)

 

Result... Only hope the box is ok this time :)

 

Mike

[seatkid]

he is going to empty, vac, flush and refil with new gas and oil..

Are they going to strip it down completely? I mean how do you empty an a/c system of oil? How do you flush an a/c system - what does this mean? According to the TIS when refilling the oil, specific quantities should be plced in the each component, compressor,condensor,evaporator and dryer individually.

 

I am not trying to be negative, just trying to understand how a proper "full" service could be done. I've a feeling the garage's words made you feel comfortable but I doubt they are going to do everything they said.

 

Which leads on to my question about "servicing" where they just vac and refill. What happens to the oil during leaks and servicing?

[GSMGuy]

Apparently, the oil is mixed with the refrigerant, therefore when emptying and vacuuming all the old refrig out, presumably the oil comes too..

 

Mike

[johnb80]

Usually the flushing is done with another gas (Nitrogen from memory), helps to purge the system of air and removes any debris etc. The oil is carried around by the refrigerant.

 

Regards - JB

[neil]

Very interested in trying this out and have followed the various links to suppliers. However, cannot seem to obtain a hose with a pressure gauge inline or the pencil type tester. Does anyone know where I can get either of these?

 

Also, does anyone know whether Interdynamics has a UK distributer for their air con kits?

[Guest JohnP]

They say that you should do at least one thing that scares you each day!

 

Just stopped trembling... I am an electronics engineer - I much prefer wires and things, rather than high pressures and nasty gasses.

 

Anyway, complete success, the aircon has worked well over the weekend, in fact, I nearly didn't do the job. Bit the bullet tonight and read the instructions three times over. The low pressure connector on my R reg TDi Galaxy is indeed behind the drivers indicator - loads of room in there. I removed the indicator housing altogether to be sure of getting plenty of room.

 

I put on rubber gloves in case any refridgerant escaped and dropped on my delicate skin.

 

The hose was duly connected to the can, then the connector went onto the low pressure point without any hiss or kick or anything. Started the engine and waited five minutes for everything to warm up/cool down. The pipe to the can is short...

 

I held the can wrapped in a rag, because it gets cold. Also, unless you wrap it in something, the can bashes the paintwork (the engines running still..)

 

Turned on the valve on the can - nothing happened. Waited for a couple of minutes and sure enough, the can is now starting to get cold. Bear in mind that I am worried sick that the comperssor will suddenly suffer from hydraulic lock because I've put too much in...

 

Anyway, if you listen carefully, you can hear when the compressor is picking up properly. The rattles reduce and the whole thing sounds tighter. The engine has to work slightly harder as well to keep to 1000rpm.

 

I kept on topping up, waiting for either the can to empty or for a more dramatic noise. After about 10 minutes, I stopped with about 1 quarter still in the can because the inside of the car was getting bl**dy cold. No need to push my good luck any further.

 

So, I think that the advice on this thread is sound - if you have any doubts whatsoever, pay the man. If you're prepared to have a go and risk the consequences, it doesn't seem so hard to do. I paid

[gazza007]

Just received my 2 cans & lead.

Postage says

[Rallim]

I believe it is the one on the left, whilst stading in front of the car (nearest the air filter), this has the larger diameter hose.

 

I tired to measure mine with the pencil guage mentioned earlier in this thread but it wouldn't measure anything confirming the need for some form of inbetween pipe is needed to use the guage.... :)

[Masked Marauder]

I believe it is the one on the left,  whilst stading in front of the car (nearest the air filter), this has the larger diameter hose.

 

I tired to measure mine with the pencil guage mentioned earlier in this thread but it wouldn't measure anything confirming the need for some form of inbetween pipe is needed to use the guage....  :(

Yes, I used the tip of a ball point pen case. But you need to cut a slot into the top of the end too.

 

And on a MK2 it is indeed the pipe on the left by the slam bar that you want.

[Velcrohead]

I believe it is the one on the left,  whilst stading in front of the car (nearest the air filter), this has the larger diameter hose.

 

I tired to measure mine with the pencil guage mentioned earlier in this thread but it wouldn't measure anything confirming the need for some form of inbetween pipe is needed to use the guage....  :(

Yes, I used the tip of a ball point pen case. But you need to cut a slot into the top of the end too.

 

And on a MK2 it is indeed the pipe on the left by the slam bar that you want.

Do you by any chance have a clearer picture of this mod MM?

I cannot use mine and love to be able to.

[Guest Scott]

Just received my 2 cans & lead.

Postage says

[Masked Marauder]

Yes, it is his standard postage rate. If you had added other items the postage would have stayed the same.

 

I must ask what his VAT number is next time I buy something though.