oil seal replacement with out the special tool

**delawarerick** · 11-30-2025, 10:07 AM

Got a 2005 mercury 8hp 4 stroke water pump wasn't peeing when I took the water pump upper housing off the rubber gromet that goes over the exit to the intake pipe was colapsed so water couldn't go up the tube got that replaced new impeller so that should be good to go. Before I got to put back on layed on side and gear oil leaked out. Now there is an oil seal under the bottom housing is that the culprit? It looks shot question is it calls for a special tool can I take mark location take old seal out turn upside down and drive new seal down with a pipe over the drive shaft to mark? Helping a friend trying to get him on the water. Any help is greatly appreciated. thanks Rick

When I took the upper water pump housing off there was some gear oil

**Carter Powell** · 11-30-2025, 11:02 AM

I think you are talking about the oil seal inside the water pump housing. If that is correct you just need to pry out the water pump base off of the shaft and then remove the oil seal. You might be able to find the same seal at a business that sells bearings and such. Usually that seal is designed to only go in one way so make sure you install it the same way. You could drive it out just using a socket with a little smaller diameter. Then when putting the new one in, put a little red locking sealant on the outside edges of the new seal and drive it in to the same position as it was before. This should do the trick. Best wishes, Carter Powell

**skialot2** · 11-30-2025, 11:21 AM

Special tools make it easier. But if you can get the seal out and install the new one without damaging anything it will work fine. I have changed hundreds of seals with just a screwdriver and hammer.

**25two.stroke** · 12-02-2025, 03:45 PM

Not quite picturing what you have...a serial number or a photo of the water pump base will help. Bigfoot vs non is different too...but I believe both of them the seal is installed from the bottom in the aluminum water pump base assembly, so that has to be pulled. Don't think any special tools are required to remove and install the seals; but you won't be doing it around the driveshaft on a fourstroke...2 stoke yes and they are a pain in the ass.

**delawarerick** · 12-02-2025, 07:04 PM

This motor is a pain simple but you have pull it all apart to get to parts. Update this motor will leak oil if laid on it's side on one side the other it won't this is by the book. This is a relabeled tahatsu. Pumps great now when you put it in gear it dies when revved up plugs good, compression good, spark good, fuel delivery good. It has 2 kill switches the one in the handle doesn't work the one on motor front does I don't know heat take gun and check book says it has a fuel filter can't find. It's has the gears are in the handle it's as if you pull a kill switch after it engages in gear and you accelerate. It has standard foot and has what looks like very few hours told less than 50. Anything could be?

**25two.stroke** · 12-02-2025, 07:54 PM

Motor oil will leak if laid on its side, gear oil will not. Gear oil will leak out of the gearcase if the water pump housing bolts are not tight because they also hold down the base and gasket.