I/H Farmall 404 Hydraulics

1. Installed new hydraulic pump. Started tractor. Hydraulics were jerky and howled like mad. Removed the plug on side of pump, there was a spring and ball bearing inside. Howling stopped and fluid blurped out. No pressure. Replaced the spring and bearing. No pressure. I suspect that the either or both the filter and uptake screen (if there is one) are plugged. Where is the uptake screen located?

2. I also suspect that the pressure relief valve is sticking. Where is that located?

3. Late last summer hydraulic fluid started leaking from the gear shift lever. I assumed that there was a worn gasket or o-ring but upon removal there is neither. The only seal seems to be the metal to metal contact of the shifter skirt to the shifter housing. There is a gasket where the shifter housing bolts to the tractor but this is not leaking. So I am guessing that no seal is required on the shifter lever and that the hydraulic fluid doesn't belong there. So why is it there?

Thanks in advance for any and all suggestions.

Kent

Oil travels from the rearend to the front mounted hydraulic pump inside the steel manifold lines running along side the right side of the battery and center housing. Small line is pressure (return) from the pump, large line is suction to the pump. To help prime the pump, loosen the capscrew plug on the top-rear of the hydraulic fiter base mounted aft of the hydraulic pump. This will let air escape from the lines and the pump should prime. Cycle the 3 pt or other hydraulic devise to purge the system of remaining air.