ENGINE DIAGNOSTIC TEST PROCEDURES
Section 6
•
EXHAUST BACK PRESSURE
- 400 Series On-Highway
(with Robert Bosch MW Pumps)
FROM FORM NO. CGED-365
EXHAUST BACK PRESSURE
14
A.
MEASURE AT POINT 3 TO 6 IN. AFTER ELBOW OR STRAIGHT PIPE
EXHAUST EXTENSION FLANGE.
B.
MEASURE AT FULL LOAD & RATED SPEED.
INSTRUMENT
GUIDELINE DATA‚
1st CHECK
2nd CHECK
WATER MANOMETER
OR MAGNAHELIC
GAUGE
p Refer to "Performance Data Guidelines", in this section.
Measure exhaust back pressure as follows:
1.
Connect pressure test kit (SE-2239) in a straight
section of exhaust pipe approximately 3 to 6 inches
after the turbocharger exhaust elbow extension
flange, as shown in Figure 28 or 3 to 6 inches after
the turbocharger straight pipe exhaust extension
flange, as shown in Figure 29.
Figure 28. Exhaust Back Pressure Test
Location with Exhaust Elbow
Figure 29. Exhaust Back Pressure Test
Location with Straight Exhaust Pipe
2.
Obtain the data at rated speed and normal operating
temperatures on the chassis dynamometer or fully
loaded on the highway. Specifications as noted in
the Performance Data Guidelines in Section 6 are 0-
6.7 kPa (0-27 in H20.
3.
If pressure exceeds guidelines, reduce restriction by
replacing muffler or exhaust piping as required.
CGES-240-4
Printed in United States of America
Page 38
