How do you charge a car A/C

[dude]

How do you determine when the correct level of charge is reached on a *****® 12 automotive air conditioning system?

How do you charge w/o using gauges?

And if you do use gauges, how do you charge it?

Please no environmental lecturism on political incorrectness of R-12. Thx

[Latte]

The Simple answer is you cannot do it without gauges otherwise how do you know the system is working properly.
The gauges SHOULD fit onto connecters depending on the age of the car you may also have to buy adapters to make them fit.
As you are putting in gas there must be a leak, is it fixed & have you pressure tested the system. If you still have a leak you might as well be peeing up against the wind.
If you are looking to buy gauges/gas,vac pump ect why bother !!!!.
Most engineers will do it for you & will refill with LEGAL GAS (See no Lecture)
and will probably only cost £50-60. Now work out the cost to buy the equipment i think you will find in this case it will be FAR cheaper to get it done correctly by someone trained than to do it yourself

Regards

Raymond

Sorry had to re-edit, the only way to check the correct level is to weigh the gas in, More expense as you will need a decent set of scales as the charge will only be a couple of hundred grams. Post what model car it is a will let you know the exact charge.

[chemi-cool]

hi dude,

automotive AC is a bit different, pressures can go crazy some times.
what you see when the car is not in motion will change dramaticly when you drive fast, a car that was standing a few hours in the sun can reach temp. as high as 60C..

this is no game and can be under certain circumstances even dengerous.

I would suggest that you do not attempt to to do it without the basic knowlege.

go to http://www.airco-climate.com/
its karl hoffman`s web site he is in the automotive AC and I'm sure he can refer you to some one at your erea or you can visit him.

chemi

[Karl Hofmann]

Dude, If you have a main stream car then there may be a sticker somewhere under the bonnet with the weight of refrigerant to be used. If you can't find the sticker then let us know what car it is and I'm sure that I will have the data for that car. Raymond is right that the car may well have a leak since it will be over 12 years old and auto a/c components are made out of the cheapest materials that they can find and are designed to corrode so that you have to buy new parts, so be sure that your system is tight before you try to charge with that oh so precious R12. The greatest crime would be to waste it!

Chemi, I'd almost forgotten that my web site existed.....I think that it may benefit from an up date.

[Brian_UK]

I'll go along with all that has been said but Ray, Chemi and Karl we don't know which country he is from so the availability of parts, tools, gases etc may be tricky.

Having a location of 'home' isn't very helpful

[Latte]

Let us know where you are Dude & maybe we can be a bit more helpful, My guess would be U.S.

PS Happy Birthday Brian

Regards

Raymond

[dude]

Yes I am in the US.

What I commonly hear is you can top off the R-12 system using the sight glass but you can't do that with R-134a.

I haven't completely lost the charge yet. There's just lots and lots of bubbles in the sight glass and it doesn't cool too well.

Automotive A/C is an open drive system and there is a polymer hose for gas to permeate through. It is pretty much a given that open drive will not be leak free forever like hermetically sealed home refrigerators.

I had a different car serviced in the past, because the A/C wasn't cooling too good, but there was refrigerant in there. They evacuated the system, then charged me for system capacity of ***** 12.

When it's $60/lb (That's about £72.70/kg for you UK people) this is a big deal.

My system takes about 1.1kg.

[chemi-cool]

hi dude.

R-12 you can buy at ebay, real cheap.

if the system is loosing charge, it have to be fixed which brings us back to the point that you need an expert!

$60 = 34 quid (webram- why dont I have that GBP sign on my key board?)

chemi

[frank]

Hey Guys - if you look at the top right hand side of this "VERY NICE NEW LAYOUT FORUM" you will notice where the poster is from. Dude is from the US of A.

[chemi-cool]

hi frank.

that happend only after raymond asked him where he was from.

before that it said "home"

chemi

[frank]

OK Chemi - I've been busy these last few days since we got the new forum

Why are we all "Registered Users"?

[chemi-cool]

if you notice, we got promoted to "friend of.....

but we still not "nice guys "

[Karl Hofmann]

Dude,

Although it is common to "Top off" an automotive system,It is also very easy for you to introduce air to the system using this method. I prefer to pump the system out, vacuum and recharge, but then I do have the luxury of having all the equipment to do that. Do be carefull of what you think is R12, because of the price that it is it is not uncommon for some creeps to sell you an R12 substitute without telling you.

The compressor shaft seals are a notorious leak spot on automotive compressors and when they haven't been run for a while they can leak very badly untill the compressor has been run for a little while and the lubricant can seal up between the shaft and the shaft seal. this is very noticeable at this time of year as folk start to use their a/cs again.

It used to be common practice to charge R12 untill the sight glass is full and then add 4oz and it was claimed that this was not possible with R134a, but I do note that Toyota still charge untill the sight glass is full and add 100g, perhaps the removal of the sight glass on the majority of vehicles was either a cost cutting exercise or a way of forcing a car owner to the main agent to have their a/c checked.....at a cost.

[baker]

A method I have heard of to keep the seal in good condition is to wire up the car aircond to the reversing lights, so that the A/C comes on whenever the driver selects reverse.

[frank]

With the car in reverse does the A/C work in reverse???

[bernard]

No but the horn will go peeb peeb

[Karl Hofmann]

LOL Warning this vehicle is cooling

[Latte]

I cant see to be honest that wiring the a/c up to reverse would help preserve seals on it. Most people only use reverse for a few seconds at a time so by the a/c has cut in you will be going forwards again & the oil won't have had time to move around the system.

I guessed Dude was from US of A because he was still able to easily get hold of R12 ( Sore point so i will move swiftly on)/

I cannot really think of a system on a car that could be wired into to switch the a/c on to preserve it. The only real way is to tell people to run it for 10/15mins each month. I know this is the last things on peoples minds during winter but is anyone thinks of a better way let me know

Regards

Raymond

[Karl Hofmann]

Many cars have variable displacement compressors and so when they don't need to cool they sap very little power....leave it on

[Peter_1]

Many cars have variable displacement compressors and so when they don't need to cool they sap very little power....leave it on

How the systems work with variable displacement? I know the common system with the inclinated, rotating swash plate.

Peter.

[Karl Hofmann]

Most variable compressors work by adjusting the angle of the swash plate, but the small VAG and MB group cars use a compressor with no electro magnetic clutch and the refrigerant flow is controled electrically via a diverter valve. the compressor runs constantly and in the event of a seizure the link between the compressor and the compressor pully will shear as they are made of plastic, this will allow you to continue your journey safely

[Bones]

With the car in reverse does the A/C work in reverse???

its just the transmission (your gear selection) which makes you go into backwards... your motor still rotates the same direction and yeh the air would still work.

purhaps an attempt of humor frank, cause i actually thought about it for a near second then thought hang on a minute :P