Figure 6-58. Removing intake valve guide using mechanical puller

6-33. Repair

a. Cylinder Interior.

(1) V a l v e g u i d e r e p l a c e m e n t .

(a) Replace any cracked, galled, eroded,

or scuffed intake and exhaust valve guides (14

and 37, fig. B-4) or guides which do not conform

t o limits specified in overhaul standards (table 6-

15). Replace and ream valve guides following

i n s t r u c t i o n s w h i c h a c c o m p a n y f i g u r e s 6-58

through 6-62.

Figure 6-57. Ultrasonic search fixture

installed in cylinder barrel

mounting flange.

(d) With the search fixture UPPER-

LOWER switch in the "UPPER" position,

N o t e . The intake and exhaust valve guides are

move the search fixture probe through the full

r e m o v e d from the cylinder in the same manner.

upward and downward travel.

Mechanical puller - 5120-448-0400 is used for

N o t e . When a heavy pulse echo enters the

intake valve guide removal and mechanical

r i g h t hand edge of the gate (view F, fig. 6-53),

puller - 5120-448-0401 is used for exhaust valve

the detector has reached the maximum down-

guide reinoval.

ward travel. Any alarm indicates a crack or

defect in the cylinder. Re-inspect the defect

1. Insert

screw of mechanical puller - 5120-448-0400

suspect area. If the alarm sounds again, the

through

the valve guide and puller (A).

2. Install

nut (B) on end of puller screw and tighten to

cylinder must be scrapped.

remove

valve guide from cylinder.

Note. Should the inspection reveal an

Figure 6-58. Removing intake valve guide

abnormally high cylinder reject rate, the tester

using mechanical puller - 5120-448-0400.

a d j u s t m e n t s should be checked to be certain the

readings are correct.

( e ) A signal appearing immediately to the

left of the gate indicates cylinder bore roughness.

The gate start may require minute adjustment

to the right to exclude this extraneous signal.

(f) Remove the search fixture from the

c y l i n d e r , empty the water, and remove the plug

from the bottom of the cylinder bore. If the

c y l i n d e r has no defects, treat it to prevent rust.

6-66