Car a/c charging chart

[chilly]

Hello All,

Does anyone know where I can download a copy of the charging quantity of refrigerant for cars, Idealy covering all major manufacturers. I dont do many car recharges but the ones i do have usualy been rebuilt from a smash ansd the sticker is missing which normaly gives you the weight of gass.

Any posts much apreciated.

[Karl Hofmann]

Chilly,

Autodata have published a couple of automotive ac books with that info in them or you could try Autoclimates tech line 0906 5565756 It is a premium rate line but it is handy when you are stuck for a weight.

[chemi-cool]

I always charge until the suction line sweats at the compressor inlet.

If a sight glass is present, just fill it up.

Chemi

[Karl Hofmann]

Chemi,

You cant charge many cars with R134a by sight glass, you run the risk of overcharging them, similarly you cant charge variable displacement compressors by pressure.

[chilly]

Agreed, Thanks for the number, I will hope to hear of a site that gives a free download of gas weights otherwise i will probably pay for the proper chart. Thanks for the info.

Incedently when i was training, i used to guage charge everything being brought up on refrigeration, So when i woprked on ac i did the same, Including when I charged cars!
I was charging a new jaguar car infront of the customer when the blow off valve whent off like a tommy gun.. I think weight chargeing is definatly the way to go

[chemi-cool]

Hi Karl,

I have never seen the charge written on any car here,

Never had any problems with it, thats the way I do it.

If you can teach me something new, I'd love to learn.

Chemi

[Karl Hofmann]

Hi Chemi,

I find that most cars with the exception of some Japanese cars have the weight on a sticker under the bonnet, The advantage of weighing in a charge is that it can quickly be charged as a liquid rather than by Vapour which takes longer.

Variable displacement compressors maintain a fixed back pressure and control the head pressure by means of a variable speed fan, so charging by pressure is more of a guessing game.

Not trying to teach my granny how to suck eggs

[Derek]

Found that most European vehicles have some indication of the requirement. Most late model Vauxhalls (Opel) seem to take around 900gm and the Fords around 700 gm. Most BMW systems (5, 7, 8) seem to stick at 1.1 kg. Watch any Far East models as they seem to of got some charges as low as 250gm.

As a rule of thumb and only for 'friends' I start with 500gm on unknown charge Europeans (200gm for small japs) and then 20gm at a time watch the sweat. A temperature probe is very handy as most manufacturers especialy Ford have hidden the system in the bowels of the engine bay behind indicators etc and this saves your fingers.

Last resort is to pop into the local Halfords sneek a peek and see if the data is in the workshop manuals.

Favourite - BMWs everything easy to reach and where it should be.
Worst - My brothers Jag XJS everything impossible to reach.
Most irritating - Ford Focus everything in the wrong place.
Worst design - 90's Vauhall Vectra bulkhead cuts through suction hose.
Industry Failure - Not putting any fine grills in front of the condenser to stop stone chip damage.