Valve Body Repair

Valve body repair is only necessary if 1 or more of the valves in a valve body do not slide smoothly in their bores. Use this procedure to free any questionable or binding valves.

Fig 1: Sticking Valve Drops Out Of The Bore
Courtesy of GENERAL MOTORS CORP.
1. Soak a sheet of 600 abrasive paper in automatic transmission fluid for about 30 minutes.
2. Carefully tap the valve body so the sticking valve drops out of its bore. It may be necessary to use a small pocket style screwdriver to pry the valve free. Be careful not to scratch the bore with the screwdriver.
IMPORTANT: The valve body is aluminum and doesn't require much polishing to remove any burrs.
3. Inspect the valve for any scuff-marks. Use the automatic transmission fluid-soaked 600 paper to polish off any burrs that are on the valve, then wash the valve in solvent and dry it with compressed air.
4. Roll up half of automatic transmission fluid-soaked 600 paper and insert it in the valve bore of the sticking valve. Twist the paper slightly, so that it unrolls and fits the bore tightly, and then polish the bore by twisting the paper as you push it in and out.
5. Remove the 600 paper. Thoroughly wash the entire valve body in solvent.
CAUTION: When you use compressed air in order to clear fluid passages and to dry parts, always aim the air pressure away from face and eyes. Always wear adequate eye protection in order to avoid injury from dirt and debris that may adhere to parts.
6. Using compressed air, dry the valve body.
Fig 2: Inserting Valve Into The Bore
Courtesy of GENERAL MOTORS CORP.
7. Coat the valve with automatic transmission fluid and then drop it into its bore. It should drop to the bottom of the bore under its own weight. If not, repeat the previous steps then retest. If the valve still sticks, replace the valve body.
8. Remove the valve, and thoroughly clean it and the valve body with solvent.
9. Using compressed air, dry all parts.
10. Assemble using automatic transmission fluid as a lubricant.