This is a very easy job, as stated the top radiator hose clamps right onto the T-stat housing. Be sure to renew the O-ring while you're at it. Also be sure you're not using cheap green coolant.

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280