Can some one please tell me exactly how much will be the readings of the gauges for charging a Mercedes 190 with r12 freon?

Actually if someone knows, I would like to know what the readings should be for a 85 300sd with 134a, on both the low and high side. My manuel doesn't say...

You need to get the pressure vs. temperature curves for the refrigerant you're using. Full charge pressure varies (goes up) as temperature increases.

I think you can get the curves from the ACKits.com website.

Rgds,
Bob
'82 300D

Here are the charts for both R-12 and R134a:

http://ackits.com/index.cfm?fuseaction=Chart

__________________
"That f***in' biodiesel is makin' me hungry."

1982 300TD Astral Silver w/ 250k (BIO BNZ)
2001 Aprilia SR50 Corsa Red w/ 5.5k (>100 MPG)

I have another question to go along with this, what means do I use to take the temp from infront of the condensor?

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Temperatures are taken with thermometers.

You can get a dial thermometer from Ace Hardware for like $2.00.

Danny

__________________
1984 300SD Turbo Diesel 150,000 miles

OBK member #23

(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
(")_(") signature to help him gain world domination

Okay cool. Just hold it infront of the condensor I presume?

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Typically its 1 inch in front of the condensor to get your reading. There are lots of cheap digital thermometers with a wire sensor. I bought one from radio shack for around 8-10 bucks if memory serves. I dangle the lead in front of the condensor to get that reading. Its also nice to stick in the center vent to get a good vent temperature reading.

__________________
Tjohn

82 300 SD
77 450 SL (gone)