JLG 150HAX Service Manual - Manual (Page 127)

SECTION 5 - HYDRAULICS
3120817 – JLG Lift – 5-31
Run the pump at least two minutes at no load and moder-
ate speed (not over 1500 rpm). if the pump becomes
excessively hot, shut down immediately and locate the
problem source.
Gradually increase pressure on pump, in 500 psi incre-
ments until the desired test pressure has been reached.
This should take about five minutes.
Delivery should run close to rated performance figures
which are averaged from testing several pumps. Some-
thing like a 5% lower reading may be used as a rated min-
imum if new or relatively new parts have been used. When
rebuilding the pump with parts from the original pump,
which, while worn, appear satisfactory for reuse, a 10% or
15% lower reading may be permitted, depending on the
performance expected from the equipment. One's own
experience will prove the best guide here.
Many repairmen measure the output at normal operating
speed and at zero pressure, then again at 1000 psi (or the
operating pressure of the equipment) and allow a volume
decrease approximating the listing below. It is a sug-
gested reference only which makes allowance for reused
parts.
At test speeds other than 1800 rpm, gpm delivery wilt vary
almost proportionately, but the same (drop-oft) figures
should be used.
Be sure to run the pump in the direction for which it was
designed and built. Driving pump in the wrong direction
will build up pressure behind shaft seal, damaging it and
necessitating replacement.
After completing testing procedures, pump is ready for
installation and immediate duty operationonequip-
ment.Againf itmustberememberedthattopreventsei-
zure,hotoilmustnot be fed into a cold pump.
GPM
DELIVERY
at 1800 rpm
100psi
GPM DROP OFF AT....
1000 psi/70
bar
2000 psi/140
bar
3000 psi/210
bar
10 - 30 1.5 - 3 2 - 3.5 2.5 - 4
30 - 50 2 - 3 2.5 - 4 3 - 4.5
50 - 70 2.5 - 3.5 3 - 5 3.5 - 5.5