Thread: Ac gauges
View Single Post
mattdavis11 mattdavis11 is offline
Just thinking out loud
 
mattdavis11's Avatar
 
Join Date: Nov 2001
Location: Close by
Posts: 6,885
More. Get the low side to 35-40. The 944 takes 950 grams of R12, or 2.09 lbs. Freeze 12 operates at a higher pressure, so the rule of thumb is 10% less than the rec'd for R12. That puts you at 1.88 lbs of freeze 12 for the system, but that also varies +/-. I'd put in a 1.9 lbs and then look at the gauges and a dash thermometer and dial it in. Keep an eye on the high side, if it gets to 275-300, shut it down and clean the fins on the condensor.

Clarks has the pressures at these numbers. Mine gets colder than this and the pressures are different, but I imagine this is for R12. I'm 134, it's 100 everyday and my vent temps are 37-42 at 2K- 2400 rpm, which is where you should dial it in. I also work on car a/c's everyday, so naturally mine is going to be damned cold.

90 °F ambient

35-40 psi Low

190-225 psi High

44-50 °F Vent
__________________
83 944
91 FJ80
84 Ram Charger (now gone)

Last edited by mattdavis11; 07-17-2008 at 07:43 PM..
Old 07-17-2008, 07:37 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)