Refacing valve seats with hand cutter 01.8 352/352 A Refacing Disassemble cylinder head. referring to 5.1/1. 2 Check valve guides and exchange if necessary, referring to 6.1/1. 3 Check valve seat. Note: If valve seats show only slight traces of wear, they can be refaced without necessitating replace· ment of valve seat rings, provided they are not ma· chined below their bottom limit. See 1.2/4 for repair size. 4 Introduce special tool No. 14 into valve guide. 5 Position special tool No. 14 and adjust cutter to seat diameter. See table on page 1.2/3. Note:
For valve seats with 45 0 seat angles the 45 0 side of the cutter head is for cutting the seat whereas the 30 0 side is for the clearing cut. For valve seats with 30 0 angles, the two sides are to be reversed. UR01-G152 6 Reface vallie seat, applying gentle pressure. 7 Measure valve seat runout. See table on page 1.2/3. Important: Check directly after finishing the valve seat. The guide drift must not be released or withdrawn before· hand. 8 Measure valve seat width; if necessary, correct to 70 0 at top and bottom. See table on page 1.2/3 . . 9 Re·assembly cylinder head, referring to 5.1/1. UKD 30 402 21 42-01 6.3/1