The desicant used in the accumulator/dryer on older cars, like TCs, will break down over time with 134a, and will travel thru the system plugging things like the orifice tube, up eventually. When you buy a new accumulator/dryer it will probably have a label that says "R12 & R134a compatable" on it. Personally, I prefer to do it right the first time, and just replace the acculum/dryer. Get this: WHen I recently converted my 91 Escort to 134a, I called the dealer to price a new accumulator, they quoted me $260! Got one at Advance Auto for $60!
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Jeff Korn
88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 20 psi, forced air intercooler, water injection, bypass valve, Ranger roller cam, subframes, etc., etc.. // 86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP nitrous, ignition, gears, suspension, etc., etc.... // 91 Escort: Bone stock winter car // 00 Windstar (wifes vehicle)
Jeff Korn
88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
11 Crown Vic Interceptor
14 Toyota Camry (wifes car)
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized