Discussion:
Aisle master slow hydraulics

Got an aisle master 20SE. The battery is in below average condition, however when sideshift is operated the pump motor operates at full speed. When tilt or lift are operated the pump is very slow, like it's still in steering only mode.

From what I can see the Motor speed is controlled by a pressure switch on the valve block, does this send a signal to the controller to tell the motor to speed up when it senses pressure? It is a DC lift, AC drive model.

I wouldn't have thought that would be faulty though as it seems to be working with sideshift. I'm tempted to think that the battery is cactus but voltage is not significantly dropping when lift is applied. It is dropping to to 42V when sideshift bottoms out though.

Thoughts?
  • Posted 13 Jun 2019 14:41
  • Discussion started by Jofork
  • Western Australia, Australia
Showing items 1 - 4 of 4 results.
The pressure switch has a small adjusting screw in the top of it, try adjusting it to see if it makes any difference, you only need to move it a small amount.
  • Posted 19 Jun 2019 19:32
  • Reply by danny_k
  • Buckinghamshire, United Kingdom
It's a valid point but the mast and tilt still operate, just very slowly. The pump motor will always be running for steering so when a function is used it activates a pressure switch on the valve block which speeds the pump up. Maybe the pressure is not building enough due to something bypassing in the valve block for lift and tilt.
  • Posted 19 Jun 2019 19:21
  • Reply by Jofork
  • Western Australia, Australia
Not familiar with this specific brand but on other brands this might be your tilt and height cut out switches which stop the operator from tilting past a certain point when forks raised past forklift and from lifting past that point when tilted forward.
  • Posted 16 Jun 2019 14:20
  • Reply by Yidneck
  • New York, United States
Ok so I found that if I bridge out the pressure switch the pump will run at full speed and lift and tilt are ok. Also, when operating the sideshift the switch will close and pump will run normally. But if I operate lift or tilt the switch won't close. Pretty strange. Anyone had similar issues to this?
  • Posted 16 Jun 2019 12:06
  • Reply by Jofork
  • Western Australia, Australia

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