120
2
1
3
4
1.
Wastegate
2.
Pressure box
3.
Lube oil
4.
Coolant
Wastegate, checking opening pressure
Special tools:
(999) 6662 Pressure gauge
9324 Nipple
Opening pressure Control rod opening
155 kPa
1.0
±
0.3 mm when adjusting
0.5–1.5 mm control value
If you suspect that the charge pressure is incorrect,
check the wastegate opening pressure according to be-
low. First check that the pressure box diaphragm seals
correctly, but replace the pressure box if it leaks. Care-
fully follow the installation instructions supplied with
the exchange kit for the pressure box. A wrongly
mounted pressure box will result in an incorrect open-
ing pressure.
2.
Remove the hose from the pressure box at the
compressor housing and connect nipple 999 9314
to the hose. Connect pressure tester 999 6662 to
the nipple. Always check to make sure the pres-
sure gauge is correctly calibrated.
1.
Place a dial indicator (0–20 mm) with magnetic
holder on the turbocompressor so that the measur-
ing probe is in line with the control rod from the
pressure box.
6662
9314
3.
With the reducer valve on 6662 carefully let in
pressure to the pressure box and observe the dial
indicator at the same time. Read-off the indicator
exactly when the control rod has opened 1 mm.
Opening pressure must not exceed 155 kPa.
Should the control rod opening deviate 0.5 mm or
more from the specified value (1.0 mm) at correct
opening pressure, adjust according to below.
4.
If necessary adjust the control rod length, in-
creased length lowers the opening pressure. The
indicated opening must be maintained within a tol-
erance of
±
0.3 mm at specified opening pressure.
5.
Tighten the lock nut on the control rod, and renew
the lock ring at the lever if necessary. Refit the
pressure box hose to the nipple on the compressor
housing using a new hose clamp.