R-12 or R-134a?

Here is a chart for both:
http://www.autoacforum.com/aacf/ptchart.cfm

I just called autozone, they have a kit with a HP hose and gauge, a LP hose a gauge and a fill hose... 39 bucks, good deal?

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1985 MB 300D/T

Fell off the WVO bandwagon when people started trying to charge $2.50 a gallon for dirty vegetable oil.

I have R134a

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1985 MB 300D/T

Fell off the WVO bandwagon when people started trying to charge $2.50 a gallon for dirty vegetable oil.

NAPA has a R-134 gauge set on sale for $39.95. Looks just the Autozone one, though.

Thanks. That does seem to make sense. I'll give it a try. Where exactly is the probe located - or more importantly the connector, so I can try jumpering it first?

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1991 M-B 560SEL Arctic White/Grey 99,000 Miles
1987 M-B 300SDL Ivory/Palomino 229,000 Miles (sold but never forgotten)
2006 Volvo XC70 Blue/Beige
1999 Porsche Boxster Arena Red/Savanna Beige
1986 Porsche 928S Goldweiss/Brown

engine not running I get 100 (max value on the gauge for low) and 100

engine at idle I get 60 LS and 150 HS

engine at 2k RPMs I get 25 LS and 150 HS

I am not sure why people are giving values for the PSI at 2K so I gave my idle measurements and my 2k rpm measurements.

the box for my gauge kit tells me that low on the low side and low on the high side means add coolant

and high - low means possible faulty compressor.. should I be checking at idle or 2k rpms?


*ETA my wife screwed up the reading, the hs at 2K rpms is probably closer to 180, but still way too low for it being 92* outside.

I fixed the Ls & HS swap!

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1985 MB 300D/T

Fell off the WVO bandwagon when people started trying to charge $2.50 a gallon for dirty vegetable oil.

bump.
anyone have any ideas-opinions-snide comments?

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1985 MB 300D/T

Fell off the WVO bandwagon when people started trying to charge $2.50 a gallon for dirty vegetable oil.

Assuming the ambient temperature is above 70ºF, you're low on refrigerant.

(and you have LS and HS reversed in your third line, post#36 )

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The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

JBAJ, please let me know what tells you I am low on refrigerant.


Just a note, I can hear a sort of a squealing noise inside the dash where I would expect the evaporator to be...

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1985 MB 300D/T

Fell off the WVO bandwagon when people started trying to charge $2.50 a gallon for dirty vegetable oil.

What's the ambient temperature when you took the pressure readings? We'll see if I'm on the track. Also while checking the pressures, hose down the condensor and tell us what that does. Pressures usually reported at 1500-2000 RPM for MVAC diagnosis, but your idle pressures were interesting, though.

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The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

I am wondering if that means my AC clutch is slipping. The temp outside was about 92 degrees. but I think I have put about 3 short cans into the system. I am wondering if I could have somehow screwed up the balance of lubricant and refrigerant... I am so sick of this AC

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1985 MB 300D/T

Fell off the WVO bandwagon when people started trying to charge $2.50 a gallon for dirty vegetable oil.

R134a conversion, particularly with a 1980's MB condensor, would have a high side of ~ 230-250 psi w/o the aux fan working at that ambient.

Jump the wires to the switch on the receiver/dryer to see if the aux fan comes on.

Most of the autopsies on failed compressors show too little oil; so I don't think that a little extra oil is your problem.

Clutch slip? check the clutch gap. should be ~the thickness of a thin style credit card. Doesn't sound like your problem. Usually smokes and screeches a bit if it's slipping.

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The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)