[mrein3]

Two things need to be done for R134a to work in these old trucks. #1 you need to adjust the POA. #2, the condenser was made for R12 which is much more efficient then R134a. If your pressure is ok but you aren't moving, you might not be pulling enough heat out of the refrigerant. Before you capture any more, take it for a spin and see if the air moving through the radiator/condenser cools it down any.