COUPLING AS 3703476 - Caterpillar

3304B, 3306B And 3400 Series Engines Equipped With New Scroll Fuel System (NSFS)A piston-type fuel pump is used on the above engines. This type of fuel pump can cause rapid fluctuation of the indicator in some fuel pressure gauges.
Only mechanical fuel pressure gauges are affected. Electric fuel gauges are electrically dampened.The addition of an orificed fitting or snubber (flexible fuel lines are also recommended) can eliminate the erratic operation of the indicator in the fuel pressure gauge.
Two orificed fittings, the 6V8090 and 5P4837 Orificed Pipe Adapters, are available for use on the fuel pressure gauge lines of the above engines. The two fittings are different lengths, but both have an orifice dimension of 0.80 mm (.031"). The correct orificed fitting can be installed on either or both ends of the fuel pressure gauge line. The fittings are less than one inch long and have 1/8 NPT.
The above orificed fittings may not control the fluctuation of some non-dampened fuel gauge indicators. In these cases install a 7S3795 Snubber.