[213 Nb] Inlet And Exhaust Valve Removal - Mack E7 Service Manual

5-101.bk Page 25 Friday, March 17, 2006 11:05 AM
[213 NB] Inlet and Exhaust Valve
Removal
Refer to Figure 5-25.
1. Attach valve spring keeper remover J 29294-B
to cylinder head.
2. Rest tool compression forks (4) on top of
upper washer (3) and center forks above
valve.
3. Depress tool handle until valve spring is
compressed. Remove valve spring washer
keys (2) using a magnet (1).
Valve spring keeper remover J 29294-B must be
repositioned for each series of valves (two inlet
and two exhaust, per cylinder). Drilled and tapped
holes are provided for each cylinder.
4
3
Figure 5-25 — Valve Spring Keeper Removal
1. Magnet
2. Valve spring washer
keys
200 BENCH PROCEDURES
1
2
200286a
3. Upper washer
4. Tool compression forks
(J 29294-B)
VALVE STEM SEALS
Refer to Figure 5-26.
A new valve stem seal was introduced into E7
engine production on 11/1/96, beginning with
engine serial number 6S2657. The older valve
stem seal has a single sealing lip, while the new-
style seal incorporates a second lip that
significantly reduces crankcase blowby. This new
seal can easily be identified by the steel retainer
band around the top of the seal lip.
To improve seal-to-guide retention, a change was
made to the valve guides. The new-style guides
have three sharp ridges machined into the upper
outside diameter surface (refer to Figure 5-26).
The new valve guides were phased into
production during the first quarter of 1997.
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