ALTERNATOR GROUP 1P7770 - Caterpillar

Precleaning Inspection
Illustration 1. Top View Of BarrelA. Do not reuse if the check valve seating surface is nicked.B. Staining here is acceptable. The new bonnet seal ring is inside this diameter. There is no need to remove light to moderate stains in this area.
Illustration 2. Plunger Do NOT mix plungers and barrels. The original plungers must remain with the same barrels. If the plunger is not acceptable, a new pump group is required. Do not proceed with this process if the plunger is not acceptable.C. Cavitation erosion above the scroll edge is acceptable.D. Plungers with worn or nicked scroll edges should not be reused.
Illustration 3. Top View Of BarrelE. A mirror image of the check valve notch is acceptable.F. Heavy staining should be removed to prevent debris from getting into the sealing joint during assembly. Visible staining "Not Easily Removed" is acceptable because the new bonnet seal ring is inside this diameter.
Illustration 4. Bottom View Of Bonnet (Left). Top View Of Barrel (Right)G. This style bonnet can have staining removed with the same cleaning process and reused.H. Multiple relief notches are acceptable.J. Light staining and fretting is not an automatic indication of joint leakage. This should be cleaned before reuse.
Illustration 5. Top View Of BarrelK. Staining and/or fretting "Before" cleaning.
Illustration 6. Top View Of BarrelL. A 7000 Series nozzle tip cap in the barrel bore will help keep the cleaning fluid on the surface. Remove the cap and flush the barrel with clean diesel fuel after cleaning. The chemical cleaning will remove surface stains, but fretting will remain. Laboratory and field test indicate a new style bonnet combined with increased bushing tightening torque [300 N m (220 lb ft)] will seal with a fretted barrel. The bushing tightening torque of 300 N m (220 lb ft) is for used plungers and barrels with face fretting ONLY. Use the standard bushing tightening torque of 260 N m (190 lb ft) in all other cases.
Illustration 7. Timing SpacerM. Debris dent in a timing spacer. Do not reuse. Manufacturing grind marks are acceptable and lapping is not required.
Illustration 8. BushingN. Do not reuse bushings with heavy amounts of spline rust. The splines must be in good condition to maintain the tightening torque. Number the bushings as they are removed so they can reinstalled in the same bores.Sealing Face Chemical Cleaning Process
1. Obtain a container of 1U-9698 Descaleant2. Provide a clean work area. Do NOT mix plungers and barrels. The original plungers must remain with the same barrels.3. Use a clean soft cloth to wipe the sealing faces of the barrel and bonnet as clean as possible.4. Plug the barrel and bonnet bores with a non-damaging material. A 7000 Series nozzle tip cap will fit in the bores. See Illustration 6.5. Use the 1U-9698 Descaleant and a cotton swab to scrub the stained sealing surfaces of the bonnet and barrel.6. Let the descaleant remain on the sealing surfaces for between two minutes (minimum) and five minutes (maximum).7. Use a cotton swab to