I have a 76 F350 with 460, I bought a conversion kit, and found that I did not have the correct fittings. I bought a pack of fittings for pre 76 vehicles, but I am not sure where to put them. I do have some R 12 pressure, and i did buy a dryer to replace mine. I took some pictures of the system as I am not sure what to do to install these fittings. I have retrofitted newr systems, but not his older type. Assistance would be greatly appreciated!



I'm not sure what is the low pressure side here, and one hose appears to have a pipe splices in, is that ok? These valves are schraderless but with screw in or out fittings?



The two right fittings are the same with the exception of the innner diameter of the second from the right bing slightly larger.

Help please! Thanks in advance!

 

Look at the compressor where the two hoses connect. There are two valves there with square headed valve stems. The valve stems are under the aluminum caps. The ones that look sort of like cones, and are pointing forward on the top one and rearward and up on the lower one. The schrader fittings are on the bottom of both valves, at least I can see one on the low side connector(upper connector). They have hex headed caps on them that must be removed for access. You use the mechanical valves to open and close access to the closed system. Schraders may not have valve stems as you note.
That York (designed anyway) probably won't like to work very well with R134. Pressures are higher than R12. When you have evacuated, flushed, and added Ester oil, you will need about 80-85% of the normal R12 charge. You really should drain the crankcase of mineral oil. There is one bolt in the middle of the 'bottom' that you remove to drain the oil. The old oil is not absolutely required to be removed, it will settle into the low areas benignly, though it does take up volume. It will not mix with the 134, so will not be carried around by the refrigerant. But, because this compressor uses a slipper to pick up its lube for the crankshaft, it would be better to have the new oil there without being mixed with the old. Ester won't pick up as much H2O as PAG does. I would use Nylog on all the fittings you open up.
tom

If you look at the picture of the compressor, you will see a bolt in the center of the crankcase area, right near the clutch wire. That would be a drain hole plug. There may be one just like it on the bottom, or the end opposite the head. It is a versatile compressor as far as which way it can mount. But, the only thing is it cannot stand on its head... heh
t

 

Thanks, which one would be the low side? I'm going to guess that I would open the square headed valve stem after putting the adapter on to fill and then closing it prior to removing the fill hose even though the new adapters have schrader stems? Thanks again!
TomP

 

Simple terms...... Low side has the Big hose.
It leads to the evaporator.

The Discharge hose is smaller and goes to the condenser.

 

I answered in the first post. The square headed valve would be opened after you connect the gauge set, and closed prior to removal. If the new fittings have schraders, then the valves are not critical to be closed before removing the gauge set.
BUT, the new fittings schraders may just be 'extension fittings' that rely on the original schrader to open/close the system. In that case, if you depend on them to contain the refrigerant, you will be disappointed.
tom

 

Thanks fellas, I missed the low side part in the upper reply, I'm gettng senile. I filled it today, I had to find a 90 degree low side port adapter, NAPA ad one. Thanks for the bolt hole tip, I pulled the top bolt and used a peristatic kidney pump to suction it out. All I had waas three cans of 134 with oil., the gauge reflected low after that, but was putting out plenty cold air. Any idea on how much one of these take? Thanks again!

 

Thirty three years ago, when it was new, there would have been a tag on the compressor or on the radiator support. Generally, they were black paint on a sheet of aluminum, with unpainted areas for the numbers to be embossed. Memory says that the compressor tags were 'tent shaped' at the top, and square on the three other edges. But, my memory is older than the truck.
tom

 

Thanks again, I found the tag, but my ocular enhancement devices do not work well enough to read it, I have to break out the shop magnifier.