LM5080 slow hydraulics

[92U 3406]

Looking for a direction to go with on this one. Unfortunately I do not have a S/N on hand at the moment.

Hydraulics are slow, story I got was it was sent out for servicing a while back and when returned the hydraulics were slow, I'd guess about half the speed they should be.

This machine has a Rexroth variable displacement piston pump and relief is set at spec (approx 3,480 PSI). I'm suspecting the pump isn't upstroking as much as it should. The hydraulics don't feel weak, just slow. I have access to a shop manual but it is very poorly written. I can't see it being a pump failure being that it happened so quickly and has not degraded any further over the last few months. Is there an adjustment someone could have monkeyed around with that would have affected the pump upstroke?

 

[mg2361]

Just throwing darts since I know nothing about your machine. Load sense differential pressure to spec?

 

[Vetech63]

Is there an adjustment someone could have monkeyed around with that would have affected the pump upstroke?

It depends on which series of pump it is. Is this mechanically cable controlled? Hydraulic pilot controlled? Or EDC controlled?

Hydraulics are slow, story I got was it was sent out for servicing a while back and when returned the hydraulics were slow,

Machine serviced? Or the pump was serviced as in a repair?

 

[92U 3406]

Just throwing darts since I know nothing about your machine. Load sense differential pressure to spec?

Couldn't find a spec. The manual is not well written.

It depends on which series of pump it is. Is this mechanically cable controlled? Hydraulic pilot controlled? Or EDC controlled?

Machine serviced? Or the pump was serviced as in a repair?

Hydraulic pilot controlled pump. From what I was told it was just a regular service where they spun a new filter on.

 

[mg2361]

I would think it would be in the 285-305 psi (19.6 - 21 bar) range??

 

[Vetech63]

Pic of pump? Several pics

 

[92U 3406]

I won't have a chance to see this machine for a couple weeks so Google images is the best I can do at the moment. Looks like an A10V Rexroth.

 

[92U 3406]

I would think it would be in the 285-305 psi (19.6 - 21 bar) range??

How is the pressure differential checked? Should load sense pressure be higher than pump output pressure?

 

[mg2361]

Pump output will be higher than load sense. Load sense differential (some people call it load sense delta) is the difference between the pump output pressure and the load sense pressure. Usually measured at idle with the all controls in neutral. If, for example, your load sense differential measured 200 psi, then you would have slow, sluggish hydraulics. If it was 400 psi, then you would have aggressive hydraulics.

I don't know if this is the correct pump. I pulled it off a google search. Obviously, you will need to find out the spec from the end user (New Holland?).