I have 444e loader and as the title states it is sluggish in forward gears but the loader acts perfectly in reverse. I have checked the filters and sumps for metal a nd have not found anything alarming yet. Although I have not yet checked the large filter inside the tank. I have checked closed loop pressure and charge pressure. My results were in neutral charge pressure was around 180psi at idle and 250psi with high rpm. With the machine in forward gear, high speed, high rpm, the high pressure goes up to about 1500psi and the charge pressure goes to 0psi. With the machine in reverse gear, high speed, high rpm, the the high pressure will get to 4500-5000 psi and charge pressure stays at 150psi minimum. With this reading would anyone have any insight as to weather the machine has a pump/motor wear issue or if there is some sort of a check valve issue in the hydrostatic/charge circuit?
Welcome to HEF O’Leary. I don’t think there is a significant pump /motor wear issue as it would be sluggish in both directions. i would try swap the forward and reverse high pressure relief valves , see if the problem follows,
Thanks for the reply! I will have to try that. I am not overly familiar with the machine yet, but I have the book and have been doing quite lots of reading! Any idea where the high pressure relief valves might live?
The high pressure relief manifold is attached to the hydrostatic pump. Likely the same place you took the charge pressure and high pressure readings The for and rev high pressure reliefs are # 24 in screenshot below.
Thank you for the images! I put the gauges in two o ring boss ports on the side of what I see to be the pressure relief valve manifold in your pictures, If I get a chance to try swapping them tomorrow I will post my results.
Good morning, I swapped the the forward and reverse high pressure relief valves, as far as I could tell my symptom did not change, pressure read very similarly.When I test the pressure going forward the charge pressure seems to stay up until I start to build a little bit of hydrostatic pressure then the charge pressure drops to 0, I read in the book that that could also mean charge check valve leakage? I would appreciate your input if you have a minute Diesel Dave.
Sorry it took so long to get back to you, was looking for a manual I agree charge check valve leakage would be a source for a single direction low charge pressure issue. .
Ok great I appreciate the input
I was able to pull the hydraulic pumps to gain access to the face of the hydrostatic pump and one of these valves had screwed all the way out and the other was loose, both were missing their o rings, put it back together and now my pressures are within spec and the loader is much more powerful, but I still feel like it may be slower than it should be in forward high range. I appreciate all the advice thus far and I will continue trying to test other pressures to see if it can go faster.
Good to here you are winning ! The screenshot below is from the 444E Operators manual ,shows the road speeds. You likely won’t get to 20 mph but should be close. .
Havent gotten very close to 20 yet, I think the ranch that owns it is going to use it as is, it was a loader in a salt pit back east so the amount of rust damage makes its value pretty low!