ENGINE DIAGNOSTIC TEST PROCEDURES
Section 6
•
INTAKE AND EXHAUST VALVE CLEARANCE
- 400 Series On-Highway
(with Robert Bosch MW Pumps)
FROM FORM NO. CGED-365
INTAKE AND EXHAUST VALVE CLEARANCE
16
ENGINE OFF -HOT OR COLD
INSTRUMENT
GUIDELINE DATA‚
1st CHECK
2nd CHECK
FEELER GAUGE
p Refer to "Performance Data Guidelines", in this section.
-
400 Series On-Highway and OEM
(with AMBAC Model 100 and
Robert Bosch MW Pumps)
•
INTAKE AND EXHAUST VALVE
CLEARANCE
400 Series On-Highway with
Robert Bosch MW Pumps
Adjust valve lash as follows:
1.
Remove valve cover.
2.
Turn crankshaft until number one piston is on
compression stroke and timing pointer on front cover
is in line with TDC mark (pin) on the pulley.
NOTE: Insure number one piston is on compression
stroke by turning both push rods by hand to
determine that both valves are closed. Valves are
closed when push rods are loose and can be turned
easily.
3.
Six valves are adjusted when No. 1 piston is at TDC
(compression) and remaining six are adjusted when
No. 6 piston is at TDC (compression). As depicted
in Figure 31 odd numbered valves are intake valves;
and even numbered valves are exhaust valves.
4.
Valve tappet clearance (lash) is specified in Valve
Lash Adjustment Chart.
NOTE: All valves are adjusted by cranking the
engine twice.
When tightening head bolts, place a .005 in. Feeler
gauge between the outside brackets and the rocker
levels to prevent binding.
DO NOT adjust valves with the engine running.
Severe damage can result from inserting feeler
gauge between valve and valve lever due to close
clearance of valve to piston.
5.
Replace valve cover. Use new rubber rings under
valve cover bolt washers to avoid oil leaks at this
point. Check that the valve cover gasket makes an
oil tight seal with the cylinder head.
Use a new gasket is necessary.
CGES-240-4
Printed In United States of America
Page 44
