5 ton pump question

[sewerzuk]

Getting ready to plan the plumbing for my hydro steering setup...I have a 5 ton Vickers pump in my hands and have a question about it. Before I take it apart I thought that somebody here might be able to answer my question...

There are 3 ports on my pump; a larger suction port, a smaller discharge/pressure port, and a small flare fitting. What is this flare fitting for? If it was on the discharge side of the pump I would guess that it was for a small power beyond system, but it looks like it is on the suction side. What is this port tied into on the 5 ton?

 

[hemichallenger]

I have always hooked the small one to the tank neer the bottom. So the tank has three lines. I do not know what it is for but I have ran one of them over 30000 miles on 1400s and still going strong turns the tires at an idle stopped.

 

[m-35tom]

just plug the small port at the pump. it is not needed. in very old hydraulic design they thought it needed a line to the area behind the seal, but in this pump it is connected to the suction line inside the pump so there is never any pressure at the seal.

tom