View Full Version : 93 RR LWB A/C Line question-Robison?

07-15-2007, 08:10 AM
On the line coming out of the firewall (evaporator to the receiver dryer), there is a series of brass adaptors. I removed these recently for cleaning when I converted to 134a. Inside, there are two shuttle valves, one looks like a spool valve, the other looks like a one way valve. Anyway, I noticed that I couldn't get any flow when flushing out the lines in and out of the evaporator. When I got everything back together, I couldn't get any pressure on the low side. I have replaced all the o-rings and the expansion valve as well.

Is it ok to run the system without these valves?