SECTION III. CLEANING
Before you get a wrench and go to work on the brakes, there is one thing to remember, keep it clean.
2. A few tiny grains of grit inside the brake system rubs like sandpaper, grinding up master cylinders and destroying
seals. The only cure for this problem is prevention.
3. Grit and dirt usually sneak into the brake system when you check or add fluid. This is true for all vehicles, but the
problem is worse on 2 1/2- and 5-ton trucks. Dirt has more chances to get into the brake system because the master
cylinder is located underneath the trap door in the floorboard..
Compressed air used for cleaning purposes will not exceed 30 psi (207 kPa). Use only with
effective chip guarding and personal protective equipment (goggles/ shield, gloves, etc.).
4. There is usually dirt, water and other debris you don't want in the master cylinder on the floorboard. Give the
floorboard a good sweeping before you open the trap door. Then use an air hose to clean the area around the filler cap.
Make sure you wear goggles when you clean with compressed air.
5. Also on 2 1/2-ton trucks, you have to remove the vent line to get to the filler cap.
Blow the area clean with
compressed air and then wipe it off with a rag.
6. The best place for the filler cap is on the master cylinder. If you check the fluid level and its low, replace the cap while
you go get the fluid and funnel. This is the only sure way to keep airborne grit and dirt out of the brake lines.