1986-1989 Honda TRX250 FourTrax 250R Service Manual, Page 189Get this manual
HYDRAULIC DISC BRAKES ASSEMBLY Coat new dust and piston seals with clean brake fluid and install them in the seal groove in the caliper(3) PISTON AND
(2) COLLAR
Lubricate the caliper cylinders and pistons with brake fluid, and install the pistons with the piston pad end facing the padApply silicone grease to th pivot collar and bootsInstall the collar and boots making sure that the boots are seated in the collar and caliper grooves properlyInstall the pad spring