Pressure And Vaccum Testing - Volvo Penta AQUAMATIC 280 Workshop Manual

Repair instructions
Before filling the drive with gear oil, it must be pres-
sure and vacuum tested to verify proper sealing during
assembly.
Pressure/vacuum test the drive as follows:
1. Remove the drain plug and drain the oil from the
drive. If the drive has not been used for some time, a
small amount of water can run out (a few drops). If the
drive has been used in the previous few days, it can
be more difficult to observe a small amount of water.
2. Please refer to chapter Technical Data for the
correct tightening torques for the upper gear housing,
intermediate housing and lower gear housing.
3. Remove the drain plug and screw the dipstick with
O-ring back into the upper housing.
124
Pressure and vacuum testing
a) Connect a pressure tester 3810152 to the drain hole
and pressurise the drive to 21–35 kPa. Turn the pro-
peller shaft(s) and the drive shaft universal joint to
check for tightness. If any pressure loss is indicated,
use a soapy water solution, or dip the drive into water
to find the leakage point. Do the necessary repairs
and then repeat the test.
b) If no pressure loss is indicated, increase the pres-
sure to 110–124 kPa. Again use a soapy water solu-
tion or dip the drive to find the leakage point if the
drive looses pressure. Do the necessary repairs and
then repeat the test. The drive must hold its pressure
before the vacuum test is done, and must not loose
more than 7 kPa in 3 minutes.
c) Connect a vacuum tester 3858578 to the drain hole
and evacuate the drive to 10–17 kPa (75–125 mm
Hg). Turn the propeller shaft(s) and the drive shaft uni-
versal joint to check for tightness. If the drive can not
hold its vacuum, apply thick oil along the joint surfac-
es to find the leakage point. The oil is sucked in at the
leakage point and when the joint is subsequently tak-
en apart, the oil is visible on the sealing surface (gas-
ket). Do the necessary repairs and then repeat the
test. No loss of vacuum must occur during the test.
d) If no vacuum loss is indicated, increase the vacu-
um to 47–54 kPa (355–405 mm Hg). Apply a new film
of thick oil to find the leakage point if the drive does
not hold vacuum. Do the necessary repairs and then
repeat the test. The drive must not loose more than
25 mm Hg (3.4 kPa) during 3 minutes.
Repair the leak and retest the unit.
NOTE! Do not fill the drive with oil unless it passes
both the pressure test and the vacuum test.