New Pump bad?

Mikeskodiak · Nov 14, 2023

I am new to this site. So, not sure if this subject has been beat to death or not? I have a 1999 Gehl Dyna lift DP4 ( an older Lull). The machine was perfect until a few months ago it would work for an hour and it would begin to slow on hydraulic power. Boom up was fine, boom in very slow. squirt out was fine squirt in very slow and then it would stop all controls or so slow it couldn't be used. I replaced all filters and changed all oils. Problem was still the same. I then pulled the hydraulic pump sent to a shop they determined the pump failed. I purchased a new pump installed and still have the same issue? any ideas? I was thinking the torque converter could be bad, however, this thing will crawl in any terrain.
Thank you for the help

Tinhack · Nov 14, 2023

I don't know anything about the Dyna Lifts but perhaps the pump is still bad.

The first question is how much pressure is it providing the system? In other words, did you do a pressure test? The "squirt test" is not only unreliable but also considerably dangerous--As in fatal or amputation.

It's not uncommon for the cylinders needing to be repacked. Here's a video of one person doing the extension cylinder. Farm Craft.