1993 Mercury 135 HP V-6 Water presssure fitting hook up?

**Carter Powell** · 08-12-2025, 05:45 PM

A friend of mine has a 1993 135 Mercury V-6 that is stock and the normal points that I would use for a water pressure fitting are taken up already. On the top of the block where you would normally remove the plug behind the flywheel there is already a plug with a hose going down to the poppit valve. What is that hose for? Is it necessary or could it be removed and just cap of the nipple on the poppit? I don't see anywhere else to plumb into it.

Many thanks, Carter

**skialot2** · 08-12-2025, 05:58 PM

Originally Posted by Carter Powell

A friend of mine has a 1993 135 Mercury V-6 that is stock and the normal points that I would use for a water pressure fitting are taken up already. On the top of the block where you would normally remove the plug behind the flywheel there is already a plug with a hose going down to the poppit valve. What is that hose for? Is it necessary or could it be removed and just cap of the nipple on the poppit? I don't see anywhere else to plumb into it.

Many thanks, Carter

Just put a tee in that hose. That is how most of mine are hooked up.

**pcrussell50** · 08-12-2025, 10:56 PM

Originally Posted by skialot2

Just put a tee in that hose. That is how most of mine are hooked up.

Carter, I have a fairly recent thread where we discuss that very thing. I think 'ski or somebody put up some snaps of just what it looks like. Easy peasy.

-Peter