SEALING RING FOR THE MASTER CYLINDER CAP ON 2.5 TON TRUCKS THAT HAVE AN APPROXIMATE 1-1/4" FILL HOLE ON THE MASTER CYLINDER.

IF YOU HAVE THE LARGER MASTER CYLINDER CAP, SEE GASKET # FC6019  

IF YOU ARE INSTALLING A MASTER CYLINDER RESERVOIR KIT OR DOING DEEP WATER CROSSINGS IT IS VERY IMPORTANT TO HAVE THE CAP SEAL PROPERLY. 

NOT FOR M35A3 OR TRUCKS WITH UPGRADED DUAL CIRCUIT BRAKES. 

PART # 7373354 NSN 5330-00-737-3354, 5365007373354