Northern Hydraulics 1164 Splitter Problem - Need help please

[quid_non]

Got an old NH 20T log splitter - ~25yrs old. 5HP, 2stage 11GPM pump, 4"x24" ram.
Worked fine for 25 yrs - recently noticed some decrease in splitting power. Now, it will pause when it meets a log, then after a few seconds a massive "POP" and it splits the log. This is in contrast to the usual steady splitting seen in the past. I have checked the oil - seems fluid levels are fine, no noticeable engine problems - it is running at full speed thru out this.

I'm thinking it might be the pump or cylinder - how can I troubleshoot and determine which one to fix/replace?
Thanks!!

 

[triptester]

The cylinder would be a good place to start. Ex tend the ram to the end of the stroke. Shut off engine and remove the hose at the ram end of the cylinder.Install fittings or hose to direct possible fluid flow from cylinder into a container. Start engine and put control lever in extend position. Little to no fluid should come from the open ram end hose. If there is fluid flow this would indicate damaged seals.
Be carefull to protect yourself from possible high pressure fluid spray.

 

[J_J]

On the two stage pumps, I believe there is is a device to shift the pump from high speed low pressure to low speed and high pressure.

It might be sticking.

They usually shift around 700 to 900 psi.

Put a hyd gage in the system and you will probably see what is happening.

Does it have a return filter and is it good. Some have a gage to tell you whether it is in bypass.