Vanagon Syncro AWD F4-2109cc 2.1L (MV) (1989)
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drill out air outlet (arrow) of pump housing, using a # 40 drill bit (3.5 mm, approximately 9/64 in.)
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disassemble air pump piston assembly
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O-ring (arrow) is not part of original assembly
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install O-ring (arrow)
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O-ring may be obtained at local hardware or auto supply stores
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reassemble air pump piston assembly with circlip in groove approximately mid-shaft
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reassemble air pump
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remove existing plastic air supply line (left arrow) with one-way check valve and discard
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reinstall air pump (right arrow)
CAUTION Be careful not to puncture one way valve diaphragm.