how to remove water pump base 1978 1400 EZ Shift?

[Captzoomie]

Hi, new here. I changed out the impeller on my 1978 mercury 1400 outboard, but am having trouble getting the water pump base out. Had water in my lower unit, so I figured I'd look at the oil seals under the water pump base, and change out that last gasket and O ring. I tried prying the base out by putting a small pry bar against the exhaust flange and rocking it from both sides. Also tried to use 2 screwdrivers to pry out from the side. Got nowhere in 2 hours. Are there any hidden bolts? (Didn't see a "Flush" bolt). Should I just jerk up on the driveshaft? Any other tips out there?

 

[racerone]

Jerking up on the driveshaft won't help.

 

[Chris1956]

You might give the gearcase a couple of PSI pressure to check for where it leaks. The driveshaft seal is an obvious candidate for leaking. The shift seal can also leak, as well as the propshaft seals, although the driveshaft leaked more often than the others on my IL6.

Use two pry bars on the base and work it up. Obviously try not to mar the gearcase. Clean the driveshaft with Emory paper and lube it with oil before installing the new seal.

It is a good idea just to buy a new pump base, rather than trying to install a new seal in the old pump base. Also, make sure you use the correct oring and base gasket.

 

[Captzoomie]

That's a great idea to check for leaks using a little air pressure!
Not sure how lucky I will be getting that base off- I tried for quite a while before putting it back together. I might test with motor muffs- if I get water in the lower unit, it's time to tear it all apart again. Is the only thing holding on the water pump base the 2 oil seals? And maybe some old gasket compound? I couldn't get it to budge.
Also, the shifter seal fit ok, but thought it could be more snug. Any reason not to put a small bit of gasket compound on the outer diameter of that rubber ring? (Maybe I find out if I have to go that route after trying the air pressure test).

 

[Chris1956]

The waterpump base is held in place by the oring and the friction of the studs.