Porta power handpump won't hold pressure

[Rougespear]

I'm using a porta power hand pump to hydraulically tension my blade.  The pump is unable to hold pressure, slowly loosing it as measured from a pressure gauge (2000psi to 1000psi over a few seconds, and continues to fall from there).  To test pressure, I'm extending a ram to its furthest extent where it bottoms out, so the blade spring-steel is not a factor in the equation.  There are no visible oil leaks that I can see.  Pump is 4 years old, but with its use level it is basically brand new.  Oil level on the pump is good.  Does anyone have any thoughts why it won't hold pressure??

[ladylake]

 You'll want to install a check valve in the line after the pump.   Steve

[bandmiller2]

Rouges, before you do anything drastic screw the little valve that releases the pressure to its seat and take a small ball peen hammer and give it a light tap to its seat. If it has been working well theirs just something under the seat. Frank C.

[Rougespear]

Thanks for the replies guys.

Ladylake: I never thought of putting a check valve in line... that's a good idea.  But how then would I release the pressure on the ram to change blades?  Would need some type of bypass valve yes?

bandmiller2: do you mean tap on the main on/off rotary valve that opens.closes the pump action?

Brent

[Dave Shepard]

I think what bandmiller is suggesting is to tap on the end of the valve handle, gently, to smash anything that might be on the seat causing a leak. If that doesn't help, then you either need to take it apart and clean it or rebuild it.

I would use the band for the tension test. Put your normal tension on it, then see where it settles. Pushing to the limit of the ram probably isn't going to be a good way to do it.

[Rougespear]

Hummm, interesting.  I did try and tap the end of the valve just now but no luck.  I unscrewed the valve handle all the way and pulled it out.  In behind there was a little stainless steel ball... all looked good so I put it back together.  And she still doesn't hold pressure.  Very odd situation...

[ladylake]

item number: 9-7961-4

Look over at Surplus Center for the above item number, should work.  I have trouble hydraulic jacks porta power floor jacks etc holding their position to trust those valves.  Steve

[Rougespear]

Thanks for that Steve, that should work well.  Now just to order one to Canada haha.  I still wonder what's wrong with my hand pump but I wonder if its prohibitively extensive to fix...

Cheers, Brent

[Nomad]

You probably just have a seal leaking internally.  A new seal kit would fix that.

[Don_Papenburg]

Is it a genuine Blackhawk  Porta Power ? or is it a lookalike from the C H  Ina company?  I had been having trouble with the latter ,so I quit purchasing  from them.  Bottle jacks were the worst. 

[MikeZ]

cyl ram seal ?

[StimW]

Under the pump handle there should be a piston that pumps the pressure. That assembly should be removable. It should have a check ball that holds pressure when you pump fluid.
I would try to remove, clean and inspect that assembly for dirt/trash.

[ely]

My dad just had to put a new o ring in his Porta power pump.