If the Enerpac benchtop hand press fails to reach pressure, likely it's because the polyurethane o-ring in the hand pump piston/plunger has failed.

> DO NOT empty the hydraulic fluid reservoir. That's not needed for this quick and easy repair.

> Remove the handle hinge pin. Yes the retainer clip is absent. I didn't take it.

> Lift the handle and coming with it should be the plunger cross pin, plunger clip, and plunger with both sealing polyurethane and backing nylon o-rings carried in a single groove. These pieces are not secured together and may fall apart by holding the assembly in the orientation that does that. Nothing much breakable here, other than toes. Hold it above the wooden part of the benchtop until disassembled, rather than over the concrete floor.

> Replace the o-rings with new. Note the new nylon o-rings are cut completely through. Otherwise they would not be able to be placed on the plunger, because not stretchy enough. There are replacement o-rings of both types in the drawer under the press (in 50-count bags, suggesting a high level of recurrence for this particular issue.)

> Replace both o-rings. Nylon on top, poly just below it. It will take quite a bit of force to slide the poly o-ring onto the plunger.

> Grit, grime, bad. Wipe clean the piston and cylinder interior before reassembly.

> Gently replace the handle/cross pin/plunger clip/plunger/o-ring assembly, taking care to keep the plunger/piston on-axis with the cylinder, to avoid damaging the new o-rings.

> Replace the handle hinge pin.

> Bob's your uncle.