JD 750 Hydraulic issue

Klaibs27 · Dec 25, 2022

So my very worn (4400+ hours) 750 was making a heck of a racket when I started her up this morning. Up until now, they hydraulics were smooth but slow and I know I need to rebuild the curl cylinders but that's a project for another time.
The motor seemed to be purring quite nicely but I think the hydraulic pump was squealing. Everything would chatter when trying to raise the bucket or 3 point and I had ZERO power steering. The dealer flushed the screen and hydraulic system multiple times when I first got it (less than 20 hours on it since then probably) and the hydraulic oil level seems OK and it's not milky at all. Take a look at the video and let me know your thoughts?

oldnslo · Dec 25, 2022

Not sure where you are located but if in area with colder temps I would check the pump inlet or suction lines to see if any cracks in a hose or loose hose clamp. Cold weather makes oil thicker so any air leak is magnified and would cause pump to be noisy and system to chatter.

Klaibs27 · Feb 23, 2023

We thought it might have been a clogged filter screen. We did a full hydraulic flush and both that filter and the spin on filter still looked good. The noise is coming more from the Selective Control Valve so we'll have to investigate further.

Henman · Aug 23, 2025

Klaibs27 said:
So my very worn (4400+ hours) 750 was making a heck of a racket when I started her up this morning. Up until now, they hydraulics were smooth but slow and I know I need to rebuild the curl cylinders but that's a project for another time.
The motor seemed to be purring quite nicely but I think the hydraulic pump was squealing. Everything would chatter when trying to raise the bucket or 3 point and I had ZERO power steering. The dealer flushed the screen and hydraulic system multiple times when I first got it (less than 20 hours on it since then probably) and the hydraulic oil level seems OK and it's not milky at all. Take a look at the video and let me know your thoughts?

It’s a little off your subject, but when you flush the system, did you had to bleed the air out of the system?