BREATHER 2354948 - Caterpillar

ENGINES
G3606 (3XF),
G3608 (4WF),
3606 (8RB),
3608 (6MC) ENGINESTHIS TIB REPLACES THE NOVEMBER 18, 1998 ENGINE TIB, COMPONENT CODE 1201 "JACKET WATER SIDE COVER BOLT BREAKAGE". DESTROY THE NOVEMBER 18, 1998 TIB. IT WILL NOT APPEAR IN THE QUARTERLY INDEX.Problem:
Some of the 0S-1594 Bolts, currently used to secure the 1W-0129 Jacket Water Side Cover, have been breaking due to high cycle fatigue. This can result in engine coolant leaks.Solution:
A new thicker jacket water side cover is being designed. This new thicker side cover distributes the sealing pressure more evenly over the entire gasket. The additional thickness also makes the joint less susceptible to gasket creep. This new side cover requires the use of 3 mm longer bolts which are less susceptible to high cycle fatigue. The availability of this new thicker jacket water side cover will be announced in a later issue of Engine News.Until the new jacket water side cover is available, a similar result can be achieved with 13 mm thick spacers and 13 mm longer bolts. The spacers distribute the clamping force over a larger area and allow the use of longer bolts. The longer bolts are less susceptible to high cycle fatigue. Several different 13 mm thick spacers are available. Use the one that is most readily available. Some possible 13 mm thick spacer part numbers are 5K-1928, 1U-2812, 6W-5458, or 148-7017. The 0S-1591 Bolt is 13 mm longer then the original bolt. This hardware may be used when an engine cannot be taken out of service to change the cover, as long as the gasket has not been extruded. If a jacket water side cover is leaking, do not over tighten the bolts. Over tightening will extrude the gasket which may worsen the leaking condition.COPYRIGHT 1998 CATERPILLAR ALL RIGHTS RESERVED