Ive recenty went from -2 imco to -3 and have experienced high water pressure. When im running say under 80 its fine, around 20-25 psi but once I get over 100 its like 35+. Im worried i might push a head gasket to far. Ive heard of adding dumps but im not sure how. any info is appreciated.

Thanks

Phill

You need pressure relief valves added. I put mine in after the sea pump but before all the coolers.
Eddie Marine sells them:
http://www.eddiemarine.com/store/car...&p=13372&c=238

An OSO member has some new, but old stock relief valves for sale. Contact Rob: [email protected]

Thanks John!

Does anybody have a kit for 500 efi's

Do not think there is a kit. Just purchase the relief valve, plumb it in the hose coming out of the engine water pump, then run dump line out side or back of boat. I used the relief valves made by merc., a little expensive, but way cheeper than replacing a head gasket.

Make sure that winter layup includes draining the dump line at the relief valve.

Merc
Water pressure relief valve
863208a3

My Merc water pressure relief valve is connected inline of the water from the drive to the sea water pump. Is this not the way it should be?

Mine are right before the circ. pump. Using teh Merc valves. Those things are worth their weight in gold. And priced so too!

Anyone have any specific installation procedures for these valves that show where they are supposed to be? I'm wondering if it really matters.......

i just ordered the one from Eddie Marine. Save yourself $30 and order it from hardin marine.