DIY Airconditioning pressure check & recharge

[joe1972]

I have a 1994 E300 diesel. (W124 ?)

To cut a long story short, I have been given a can of R134a, and aircon valve & tube with gauge built-in.
My Air conditioning doesn't work. I would like to check the propellant/refridgerant pressure, and fill/ top up the pressure.

So, where abouts is the relevant valve on the car to connect up this can?

Personally, I would've rather taken it to the local Kwikfit for system top-up, but I've been given this stuff, so may as well have a go! I use to work with P11,12 and 134a a while ago, so know what a waste of time I could potentially spend with this can kit! (here goes emptying the can through holes in the system, maybe?!)

I've read all i can find here on airconditioning topics, but my apologies if I've missed some and repeating what's on here elsewhere.
I've not had the car long, so I'm on a steep learning curve.

any advise/ pointers, welcomed

 

[Dosco]

Caution...

...are you sure your system contains the gas you refer to given the age of the car. I am not sure when R11 / R12 / R134 and the rest of them were phased out.

You might want to get in touch with an indie to check it out for you, mixing gases might just bugger up the system.

 

[Bolide]

I'd throw the can in the bin and get an expert to do it

My local chap charges £40 for an a/c top up - so it's not expensive

Nick Froome
www.w124.co.uk

 

[television]

Yes as Bolide, throw it away, its not worth the hassle when it all goes wrong

 

[nickcc101]

Tried a couple of the top up cans bought off ebay some years ago when i had a Focus, even bought the pressure gauge. Found it to be a waste of time and money as aircon remained u/s. Took to agent who carried out recharge, worked ok afterwards.

 

[merc convert]

Just had mine done £45 Kwik Fit No recharge no costs. All ok.

 

[joe1972]

Thanks for the replies.
Yes, it definately contains HFA based R134a, not the CFC based R11/12.
That's assuming the plaque in the engine bay (next to vin plate) is correct!.....it should be as by 1994, all CFC based propellants/refridgerants were about phased out in the EC, other than those needed for medicines/ essensials, which I believe are still being used until supplies run out (ie in theory the manufacture of CFC has stopped)


So, I take it from the replies none of you know where on the car the A/C top up valve is??

Could do with pointers, as the car / merc ownership is new to me. I'm thinking, like many A/C systems it needs a minimum of 2bar pressure to work?

I've not even got a Haynes manual for it yet!

 

[joe1972]

anyone?

 

[joe1972]

Found it.
Charge point is just off the pipe from the condenser.
Will charge it as soon I get chance. I've not spent anything on the kit, so worth a try.

Will post as soon as I've emptied the can into the atmosphere! lol

 

[LYNALL]

I have used these cans of e bay several times with great success.

Discovery TDI/TD5,Mini One/Cooper,Merc ML

One of the valves is hidden behind the fake grill that keeps fingers from the elec fans on my w210.

Make sure engine is running and you want it to go on the suction side ie the larger pipe iirc!




Lynall

 

[joe1972]

Thanks Lynall,
Yes, got it....thanks for that. It was going to connect to the wrong point.
Pressure was very low, but is now great....I went out for a run, and since left it over night. Just checked the pressure again, and it's still the same.
HOWEVER,.....the A/C is working well...but a little TOO well! If I switch the A/C button on the dash it just goes icy cold no matter what the temp dials are set to?! Those dials dont seem to do anything when the A/C is off.

So, at the moment I can be toasty warm in the car, or freezing cold. There's no inbetween, unless I start opening windows/sunroof (which kinda defeats A/C really! lol, unless I want to try chill down the world!)

Looking at the DIY section, there's a brill A/C trouble shooting guide. I printed it off and went investigating under the bonnet. From what I've read, and the fault, I'm thinking the 'temperature sensor' is at fault????

What do others think?

And, whereabouts is the temperature sensor? (and what does it look like?)

cheers