Iam preparing for the coming R134a conversion to the A/C on my '89 760T. It looks to be very tight to get at the fittings from the evaporator to the accumulator and evaporator to the high pressure line. There is not enough clearance between the fittings and the engine to get a standard length wrench on the fittings and since they are stacked on top of one another with a vacuum block of some sort above, you can't go up with the handles. Are special offset wrenches required?

I checked the size of all the fittngs on and around the accumulator. There are 4-pairs not counting the pressure switch. In total there are 7 different sizes, some metric, some American Standard, and some seem to be inbetween. Is there a conspiracy to keep the amature mechanic away from the A/C system? I was planning to make sure I had all the right size end-wrenches, but not sure now. When I converted the '740 there was plenty of room for two adjustable wrenches, but that is not the case on this model.

Is it OK to spray these fittings with PBlaster? Is there a penetrating oil that works better on aluminum?

Thanks in advance,

Dan