S h o p Notes 2.0
DETROIT DIESEL 53
3. The bluing solution bath.
There are several important safety precautions to be
followed for preparing and using the solutions.
4. A cold water rinse.
Protective clothing such as rubber gloves, rubber
aprons and protective glasses contribute to the safety
5. An engine lubricating oil bath (180 -212 F.) to rust
of personnel carrying out the procedures. When
proof. The bluing tank should be a double walled, 1-1/
preparing the solutions, the compounds should be added
2 " installed type of No. 10 gage steel.
to the water and not water added to the compounds.
The dipping tanks should be properIy vented and all
The temperature of the sodium hydroxide, sodium
fumes exhausted to the outside, atmosphere. Since
nitrite and phosphoric acid solution for bluing steel
parts should be 295 to 305 F. The boiling point of
temperatures of the caustic solutions exceed the
the solution is directly related to its concentration.
bowling point of water, any splashing encountered
Therefore, when the boiling point is too high, the
while adding make-up water can cause serious burns.
solution is 100 concentrated and the volume of water is
Always add water slowly and with extreme care. When
probably low. When this occurs, the boiling point can
the parts to be dipped are cold, caution should be
be reduced to 300 F. by adding water. The parts
taken to avoid splashing that might occur when the
should be placed in the solution for 15 to 30 minutes.
cold parts come in contact with the hot solutions. A
heavy wire-screen type basket, suitable for holding a
It is extremely Important that the parts be free of oil
quantity of injector bodies, is recommended for
before placing them in the bluing bath. Oil will
dipping the parts in the solutions.
produce a varied color part.
INJECTOR COMPARATOR AND CALIBRATOR READINGS
before the air is purged from the injector and lines, or
from an air leak on the vacuum side of the pump.
3. Counter Improperly Set: The counter is set at the
factory to divert the injector output at 1,000 strokes,
This should not be confused with counter overrun that
will vary from 2 to 6 digits, depending upon internal
friction. The fuel diversion is accomplished electrically
and will occur at 1,000 strokes (if properIy set)
although the counter may overrun several digits.
4. Test Oil: A special test oil is supplied with the
calibrator and the comparator and should always be
used. If regular diesel fuel oil (or any other liquid) is
used, variations are usually noted because of the affect
of the oil on the solenoid valve and other parts.
The fuel oil introduced into the test oil when the fuel
injector is placed in the comparator or calibrator for a
Fig. 3 - Checking Fuel Output
calibration check contaminates the test oil. Therefore,
it is important that the comparator or calibrator have
Several factors affect the injector comparator and
the test oil and test oil filter changed every six months.
calibrator output readings. The four major items are:
or sooner if necessary.
1. Operator Errors: If the column of liquid in the vial
In addition, other malfunctions such as a slipping
is read at the top of the meniscus instead of at the
drive belt, low level of fuel oil, a clogged filter, a
bottom. a variation of 1 or 2 points will result. Refer
defective fuel pump or leaking line connections should
to Fig. 3.
cause bad readings. A frequent check should be made
for any of these tell-tale conditions.
2. Air In Lines: This can be caused by starting a test
SEC. 2.0 Page 3
August, 1972
