PSP FOR REPLACING FAILED CYLINDER HEAD GASKETS ON CERTAIN 3406B TRUCK ENGINES - PS0450 - MAILED US AND CANADA, COFA, CFE L, TRUCK TEPS, LIMITED COSA Caterpillar

(Revised August 1990)
U-70
AU-44
E-45
O-60.1
TT-4
1124   PS0450
NOTE: This Program can only be administered after a failure
occurs. The decision whether to apply the Program is made
by the dealer. When reporting the repair, use "PS0450" as
Part Number, "7755" as Group Number, and "96" as
Description Code.
NOTE: This Revised Service Letter replaces the April 12, 1990 Service
Letter. Changes have been made to the Affected Product, Parts
Needed, Action Required, and Service Claim Allowances.

December 31, 1990

The cylinder head gasket may fail on certain 3406B Truck Engines and result
in damage to the cylinder block, spacer plate, and/or cylinder head.

Model Identification Number
3406B 7FB86000-Up
9HB1-299
4MG1-62276
8SB1-2514
7XC1-1549
8TC1-8518

*1 - Gasket Kit-Cylinder Head
**1 - 9L5854 Band (Filler)
**1 - 5N0093 Insert (.106")
**3 - 6V5121 Seal
**1 - 2W3815 Insert (.060")
**1 - 2W8601 Plate-Spacer
**1 - 7W3550 Liner
**1 - 9Y3368 Insert (.030")
* Part number varies by application. See the parts book microfiche and
choose the appropriate gasket kit. Make sure the gasket kit contains the
7E6000 Cylinder Head Gasket.
** Quantity listed is per cylinder. Use as required if replacement is
necessary due to a head gasket failure.

After a cylinder head gasket fails, check the fuel settings and timing
advance to insure that improper settings did not cause a failure.
Disassemble the engine and inspect the cylinder head, cylinder block, and
spacer plate for erosion or warpage. Verify that extensive operation after
failure has not caused damage. If any damage exists, repair the damage.
Resurface the cylinder head bottom deck if damage is repairable, or replace
with a remanufactured cylinder head, if necessary. Wear or erosion under the
liner flange will require a stainless steel insert, and possibly a new liner.
(See the November 14, 1988 Service Magazine Article titled "New Liner Seat
Available For 3400 Engines.")
NOTE: Head gaskets can leak combustion without visual damage to fire
ring assembly. Do not replace a cylinder head for an "assumed"
internal crack unless a crack is visible or one is verified with
leak test. If coolant loss is encountered, also inspect the OEM
radiator shunt line installation, cylinder head vent line, and
cylinder liner flanges for potential vertical cracks.
Follow the procedure in the Service Manual and assemble the engine using a
new 7E6000 Cylinder Head Gasket. Use the August 1989 Truck Engine News
Article titled "Improved Head Gasket Used; Summary Of Earlier Gaskets And
Service Tips" as reference.
Liner projection measurements should be recorded in the dealer service report
for reference.

Product Caterpillar Dealer Suggested Customer Suggested
mile/age Parts Labor Hrs. Parts Labor Hrs. Parts Labor %
(C/L) (Sell)
0-149,999 100% 18 0 0 0 0
0-24 mo
150,000- 100% 9 0 0 0 50
249,999
25-36 mo
250,000- 100% 0 0 0 0 100
300,000
37-48 mo
NOTE: This is an 18-hour job. Additional time can be claimed as
follows:
2.0 hrs. for first liner that needs to be removed.
.5 hrs. for each additional liner.
1.0 hrs. for first cylinder that needs counterboring.
.5 hrs. for each additional one.

Any parts removed (with the exception of cores used for Caterpillar
Remanufactured parts) can be rendered useless and scrapped immediately upon
completion of the repair.