Super 55 Hydraulics - Revisited

I will apologize up front. I spent all my cash on the tractor and haven't purchased a shop manual, but it is on my list to do. I'm pretty mechanically inclined, so hopefully you guys can point me in the right direction.

The tractor is a 1955 Super 55 with an upgraded hydraulic cover (filter canister out the front) and auxilliary hydraulics. A pressure reading on the Aux. Hyds. only show about 40psi. The lift arms have raised on occassion, but rarely and not reliably. From doing some research and searching this forum, I've gathered that I'll need to:

1. Check the external Over-pressure Valve and make sure it's clean and working properly
2. Make sure all passageways through the aux. hyd. control box are unrestricted
3. Check the internal Over-pressure Valve and make sure it's clean and working properly
4. If any of the 3 above don't fix it, dig into the hydraulic pump for a possible rebuild.

Here are my questions that I need a little guidance on:

1. I checked to make sure the filter was in good condition last night and found that I don't believe it was properly installed. I removed the cylinder to find a ceramic (?) filter inside and a spring floating down the middle of the filter. How does this go together and what is the purpose of the spring? Do I have parts missing?

2. Where is the external Over-pressure Valve located?

3. Where is the internal Over-pressure Valve located?

4. What do I need to look out for when removing the hydraulic cover? Will I need to pay special attention to the gearshift mechanism, or is it contained and easy to see how it goes back together?

5. I'm assuming that I'll need to drain some of the hydraulic fluid from the reservoir to dig into these areas. Is the correct drain the rear-most plug on the underside of the tractor?

Thanks in advance for your help and patience on this. I know it would be simpler to have the shop manual, but please bare with me until I can get one. I greatly appreciate it!

Thanks,
Justin in Indiana

Justin
in Indiana