Measuring Intake Air (Boost) Pressure - Komatsu WA250-6 Shop Manual

110 Testing and adjusting, Part 1

Measuring intake air (boost) pressure

Measuring intake air (boost)
pressure
a Necessary tools
Symbol Part No.
1 799-101-5002 Hydraulic tester
F
2 799-201-2202 Boost gauge kit
k
When installing and removing the measur-
ing instruments, take care not to touch a
hot part of the engine.
k
Put chocks under the tires securely.
k
When measuring, check that there are no
persons around the machine.
a Measure the intake air pressure (boost pres-
sure) under the following condition.
Engine coolant temperature:
q
Hydraulic oil temperature:
q
HST oil temperature:
q
1. Measurement with monitoring function
1) Referring to "Special functions of machine
monitor (EMMS)", select the real-time
monitoring function in the service mode.
2) Display "CHG PRESS-A" in the monitoring
functions of the machine monitor.
a Monitoring item
Code No. 36500: CHG PRESS-A (Boost
pressure)
3) Press the accelerator pedal gradually to
the high idle and measure the boost pres-
sure when HST stalling and hydraulic
stalling.
a Do not keep the HST stalled for more that
20 seconds so that the HST oil tempera-
ture will not exceed 120°C.
WA250, 250PZ-6
1
Part Name
Within operating range
Within operating range
Within operating range
2. Measurement with measuring tool
1) Open the engine right side cover.
2) Remove air boost pressure pickup plug (1)
(R1/8).
3) Install elbow [1] in hydraulic tester F1 and
nipple [2] in boost gauge kit F2 and con-
nect pressure gauge [3].
4) Start the engine and increase the coolant
temperature to the operating range.
5) Run the engine at medium or higher
speed to drain the oil from the hose.
a Insert the connecting parts of the
gauge and hose about a half and
open the self-seal on the hose side
repeatedly, and the oil will be drained.
a If Pm kit (A) is available, you may
drain the oil by using the oil draining
coupling (790-261-1130) in that kit.
a If the oil is left in the hose, the gauge
does not work. Accordingly, be sure
to drain the oil.
6) Press the left brake pedal securely.
7) Release the parking brake.
8) While pressing the brake pedal, set the
directional lever to the F (forward) or R
(reverse) position.
k
Keep pressing the brake pedal
securely.
SEN03836-01
21
30-110