FREON!! but you can convert it to R-132a. Buy a kit on any auto parts dealer.
I have a 93 previa. I took it to a mechanic because it wasn't cooling. they recharged it after replacing the nipple on the system with one that takes the newer freon.
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By using water
Follow the link below to the Previa user group.http://autos.groups.yahoo.com/group/previa/message/32333
approx 6.1lt
R134A
above heater controls center of dash
chain chain
The 1993 Chevrolet suburban C 1500 5.7 liter engine air conditioning system has a Freon capacity of five pounds. The Freon capacity should never be exceeded.
It is usually written on the compressor.
take it to a shop it needs to be reclamed