TM 9-2815-225-34&P 3-50.  ENGINE RETARDER REPAIR (Contd) LOCATION/ITEM ACTION REMARKS a.  Disassembly (Contd) 14. Two slave piston retainers Remove from brake housing (20). (16) 15. Two slave piston springs (17) Remove from two pistons (18) or Retain slave piston springs (17) (19). for testing. 16. Two slave pistons (18) or (19) Remove from brake housing (20). Piston (19) is for milled cylinder heads. 17. Harness (3) Disconnect from terminal (10). 18. Terminal (10) Remove from brake housing (20). Inspect.  Discard if insulation is cracked. b. 19. Two control valve Mount in spring tester Load at 1.625 in. (4.128 cm) inner springs (23) (3375182) (25) and check. 62.5-69.5 lb (28.4-31.6 kg).  Load at 1.478 in.  71.5-80.5 lb (32.5- 36.6 kg).  Free length 2.58 in. (6.553 cm).  Number of coils is approximately 13.  If operation does not meet specifications, replace control valve inner spring (23). 20. Two slave piston springs (17) Mount in spring tester Load at 0.5 in. (12.7 mm): 4.7-5.3 (3375782) (25) and check. lb (2.1-2.4 kg).  Load at 0.812 in. (2.062 cm) 0.7-1.3 lb.  Free length 0.9 in.  (2.286 cm).  Number of coils is approximately 15.  If operation does not meet specifications, replace slave piston spring (17). 21. Two control valves (21) Must move freely in their bores. Replace if worn or damaged. 22. Two slave pistons (18) or (19) Must move freely in their bores. Replace if worn or damaged. 23. Two slave piston retainers Check for wear and damage. Replace if worn or damaged. (16) 24. Two control valve outer Check for wear and damage.   Replace if worn or damaged. springs (22) 3-308