Thought about you when I saw this pic on eBay last night: http://i17.ebayimg.com/01/i/01/11/28/2f_1.JPG This is what Ford used at least to mid 1980's to meter freon *AFTER* the evaporator. Responds to suction on the low side, not high side pressure. Very different from GM, but works like a charm. Big vapor line passes through the valve. Red cap on the bottom is a liquid bypass line from the bottom of the evaporator if system ices up (usually caused by stuck open expansion valve, which is itself NOT the metering device -- just kicks off refrigeration cycle then closes). Black cap is a gauge port for the valve only, NOT a shrader valve for the low side in general. Note that 1979 and later STV's are slightly smaller and will not fit lines on 1978 and earlier vehicles. Here's a rude surprise: In 1979 Ford eliminated the low side shrader valve. Unless you retrofit with an earlier style line, is no way to charge A/C system from cans. Can NOT do it through the gauge port on the STV. Apparently Ford wanted you to use a pressurized machine that measured freon as a liquid then pumped in through high side. I simply replaced low side plumbing on my 1979 Lincoln with a line from a 1972 Galaxy. And note: that A/C system is my tightest! (Puts to rest any rumors that rubber A/C hoses can't withstand age). Bill Robertson #5939 _____ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/DMCForum/ * To unsubscribe from this group, send an email to: DMCForum-unsubscribe@xxxxxxxxxxxxxxx <mailto:DMCForum-unsubscribe@xxxxxxxxxxxxxxx?subject=Unsubscribe> * Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> .