Losing coolant again

[doug4320]

I recently replaced the riser gasket on my coolant reservoir. It held coolant but started leaking again. We also changed the seals on the water pump. We seem to have be leaking coolant from a small hole on the bottom drive. I dont know what else to check. Any suggestions besides dynamite?

 

[Bt Doctur]

I dont know how to answer because I dont know what it is you have.

 

[doug4320]

Its an 1985 mercruiser 170

 

[Bt Doctur]

did you use the Merc gasket for the riser.there is 1 for cast iron manifold and 1 for aluminum manifold. A/F only exits the riser if the riser is shot or the gasket is incorrect.

 

[doug4320]

All i know is it wasnt a metal riser. The marina said the 85's only used a non metallic riser and no gaskets. The pre 85's used metal riser and gasket. What is the little hole in the bottom drive? Its a cast iron manifold

 

[Bt Doctur]

stay away from those people.
http://www.marineengine.com/parts/m...EXHAUST+MANIFOLD+AND+EXHAUST+ELBOW+(ALUMINUM)

http://www.marineengine.com/parts/m...XHAUST+MANIFOLD+AND+EXHAUST+ELBOW+(CAST+IRON)

 

[doug4320]

We used that gasket but i thought i saw a parts diagram before with one metal riser and two gaskets.

 

[Bt Doctur]

might be the block off plate to isolate the riser from the manifold on V6 or V8 motors.
the only way A/F will exit the manifold on your engine is if the riser or riser gasket is damaged. only the exiting water from the heat exchanger goes thru the riser