farmall 400 hydraulics

I bought a 400 farmall been setting for 6 years in barn nice tractor every thing working except hydraulics Wont raise fast hitch I changed hydralic oil and filled Doesnt seem to change motor noise at all when working lever Im thinking some thing is stuck from setting but dont really know very much about 400 Any ideas where to look Thanks matt

Put the front wheels lower than the rears by about 18 inches. Use an air tank or small compressor to put no more than 20psi in the reservoir (you will need to make an adapter!). With it running and pressure on the res. Work all levers and steering (if power) back and forth for at least 4 or 5 minutes. There is also a tiny screen in the pressure regulator of the valve block that can be an issue. Look at the parts diagram in caseih.com search for parts. Jim

has power steering but has seperate pump above goveror

While running, does the engine seem bogged down like the pump is working/trying to put out presure? I had that problem on my 300...as previously mentioned, there is a small screen inside the pressure regulator block, if this is plugged or collapsed on itselt (like mine did) it will cause your problem. If this is the case, the pump will also get very hot very quickly while tractor is running.

Was the system full of fluid before you got the tractor? Either way it could also be air locked (also previously mentioned). My 400 did that once to me while changing hoses on the loader. I took the breather tube off the top of the reservior and stuck my rubber tipped air gun in the hole. With the tractor running, give it a little shot of air and the pressure should push the fluid through the lines and the air out.

While you are checking these things, it would be a good idea to throw a wrench on your 3 valves and make sure they are all set to either single or double acting. There are roll pins on the top that is supposed to point to which way they are set but those pins can get bent or twisted...if one of your valves is stuck in the middle it would also cause your problem. That also happened to me on the 300 I had.