PRIORITY - FLAME ARRESTORS NEED TO BE INSTALLED TO PREVENT MANIFOLD EXPLOSIONS ON CERTAIN 3512 AND 3516 SPARK IGNITED ENG INES - US, CANADA, LIMITED COSA Caterpillar

U-134
O-77.2
PRIORITY
1079 PI3321
COMPLETION DATE  

February 28, 1989  August 31, 1989

Inlet manifold explosions or backfires on 3512 and 3516 Spark Ignited
Engines can damage the cylinder head spacer plate. The installation of
the flame arrestors will result in a slight increase in inlet manifold
pressure.

Model Identification Number
3512 4KC91 - 101
3516 3RC73 - 128

Dealers will need to order parts for this Program.
3512  3516
12 - 9Y5322 Arrestor  16 - 9Y5322 Arrestor
24 - 7N5080 Gasket 32 - 7N5080 Gasket
12 - 7N5089 Gasket 16 - 7N5089 Gasket

Remove the inlet manifold elbow, flange and gaskets.
Install the 9Y5322 Arrestor between the two 7N5080 Gasket at the joint
between elbow and flange and the cylinder head.
Remove a 1S9039 Spacer from the 7W5496 Exhaust Bypass Group to
compensate for the additional inlet restriction.
NOTE: Do not remove the bypass valve from the engine.
If the engine is equipped with a high manifold pressure shutdown,
increase the setting to a maximum of 120 kPa (17.5 psi).

Caterpillar Dealer Suggested Customer Suggested
Parts Labor Hrs. Parts Labor Hrs. Parts Labor Hrs.
(D/N) (Sell)  (C/L) (Sell)
3512
100% 7 0 0  0 0
3516
100% 9 0 0  0 0
NOTE: This is a 7-hour job on 3512 Engines and an 9-hour on 3516
Engines.

Handle the parts in accordance with your Warranty Bulletin on
warranty parts handling.
MAKE EVERY EFFORT TO COMPLETE THIS PROGRAM AS SOON AS POSSIBLE.