Cleaning. - TM-55-1930-208-240253

TM 55-1930-208-24

4-10. HEAD, CYLINDER - Continued.

b. Cleaning.

(1) Remove all screw-in type plugs.

(2) Scrape off any gasket material.

(3) Agitate the cylinder head in hot-tank containing an alkaline solution (item 2, Appendix C).

(4) Wash cylinder head in hot water to remove all alkaline.

(5) Agitate cylinder head in a bath of pickling acid (item 20, Appendix C).

(6) Allow cylinder head to remain immersed until bubbling action stops.

(7) Lift cylinder head and allow it to drain.

(8) Reimmerse cylinder head in the same acid for 10 minutes.

(9) Repeat steps (7) and (8) until thehead is free of scale.

(10) Rinse the head with clear hot water to remove the acid.

(11) Neutralize any acid clinging to the head by immersing it in a tank containing alkaline solution (item 2,

c. Inspection.

(1) Magnetize cylinder head. Cover with a fine magnetic powder or solution. Magnetic particles will gather in

cracks, revealing and locating cracks. Demagnetize cylinder head after completion of inspection.

(2) Inspect cylinder head by applying fluorescent penetrant to areaof cylinder head suspected of being cracked.

Wipe off excess penetrant, then apply developing powder, which will drain penetrant from cracks. Penetrant

will glow under an ultraviolet light.

(3) Refer to figure 4-11 and pressure test cylinder head.

(a) Assemble tool set J28454 to cylinder head.

(b) Install rubber stoppers on bridges.

(1) Large stoppers are installed on long center bridge feet opposite notch and on long end bridge feet

closest together.

(2) Small stoppers are installed opposite large stoppers on center bridge and end bridge feet and on all

short bridges.

4-20