Pressure above “tare” weight of grab, (“cylinder pressure” with grab hanging is normally about 18-22 bar depending on weight of grab, if this pressure rises above this it thinks its weight in the grab and will not re-set for next grab weight) Solution: leave grab on ground open small pipe and release pressure this will then reduce the “cylinder pressure” on the screen.
During loading it stopes working (green bar on R/H/S)?
(Read above), there is a little bit of oil coming over tap and over time pressurizing link line.
No power at unit?
1amp fuse next to on/off switch (external version) 3amp fuse in white box (cab version)
Total load not accurate?
Hold F1+F2 until “Auto” is on bottom of screen this takes a better average weight of grab weight, With “Auto” not shown it only takes one snap shot weight of grab.
Pressure doing too much fluctuation to take weight?
1mm restrictor missing form either end (ram/sensor)
Truck Hydraulics
What pump should I fit to my truck?
98cc and 108cc bent axle pump are most common size, this means every revolution that is the output of this pump. So you could have small pump running fast or big pump running slow to get same output (cranes usually require 90 liters/min).
What engine RPM should truck run at for correct flow?
This depends on type of truck gearbox and gear drive to drive pump and of course pump size, the only way to know what engine RPM you require is with hydraulic flow meter connected to obtain correct l/m.
What direction should pump run?
This depends on type of drive on gearbox, some have a drop gear this means the direction is reversed!
Can I change direction of pump by changing pipes?
Normally no, always the bigger port is feed from tank and smaller one is pressure. Most pumps have arrow to indicate direction and you can open the 4 screws and turn end plate on pump (do not dismantle just turn end-plate in position).
Difference between tipping hydraulics and crane?
Tipping usually set at lower pressure (150 bar) and has a single pipe to tipper function through an air/hydraulic tipping valve with internal relieve valve. Crane has 2 pipes feed/return and can operate up to 350 bar pressure, good practice for this arrangement is to have relieve valve on the truck chassis incase a pipe disconnects.
Is hydraulic cooler required?
If crane only loads its own trailer and set correctly then it should work without cooler but it depends on pipe size, duration of work etc,
What size pipes should be used to plumb truck?
Tank to pump, as big as possible need as little resistance to flow as possible, ideal 2” and don’t forget tap! Pressure line: 3/4 will comfortable handle 90-100 l/m. Return line: 1” will comfortably handle 90-100 l/m.
Should quick couplers be used?
¾ for feed 1” for return Flat Face fitting have a longer life and are safer wit less risk of disconnecting.
Where should return line be plumbed into tank?
Proper place is below oil level or if through return filter on top of tank then oil level must be above bottom of filter at all times, if not then there is a high risk of “aeration in the oil” this will lead to cavitation’s in pump this will cause premature failure.
Gear pump V bent axle pump?
Gear pump for lower flow and lower pressure (usually tipping function) Bent axle pump for higher flow and higher pressure (usually crane or walking floor)
What do I need to consider when fitting Hydraulics to truck?
Get picture of plate on gearbox (usually a silver plate) Decide what it is required for (tipping/crane) Find out flow/pressure requirments. RPM you want truck to run at. Where to put oil tank, side/top of chassis.