Monovalve. Get a monovalve repair kit ($20) from Fastlane. Simple to replace. 4 screws. Pull out the diaphragm assm. Reinstall 4 screws. easy peazy. Japaneazy.

__________________
Frank
84 500SEL EURO 101K ( JUST LIKE MY 1ST WIFE. GLAD TO GET RID OF HER! )
85 300D 310K (sold)
90 350SDL 184K sold
83 300D 118K (sold)
88 300E 153k (sold)
93 400E 105K (sold)