Changing water pump - how do I get the impeller off?

**OldMerc** · 08-11-2004, 07:41 PM

I have a 1976 Mercury 1500. I'm trying to change the water pump, and convieniently, the pages talking about this are missing from my manual.

I've got it all taken apart, but I can't seem to get the old impeller off. How does it come off? Do I just need to pry on it with a screwdriver?

**crazy horse** · 08-11-2004, 08:02 PM

The impeller should slide up the drive shaft. They can get frozen on the older shafts, If you pry on it make sure you don't damage the base. I've had them bad enough that I have to take a cold chisel and split the impeller at the key slot, If you have to do that make sure you don't damage the drive shaft with the chisel. The impeller hub is brass so it will split without to much hammering . After you get it loose make sure you clean the drive shaft so the new one will slide on without any force being applied

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**OldMerc** · 08-11-2004, 08:08 PM

Thanks, I just wanted to make sure there wasn't anything special I need to do to get it off. Putting a little WD-40 or something on it should help, right?

**crazy horse** · 08-11-2004, 08:32 PM

Yep, That's what I'd do first. They will loosen up with a little work most of the time.

**OldMerc** · 08-11-2004, 09:16 PM

Ok - it's off. Now what's the trick to making the new impeller fit under the cover?

**crazy horse** · 08-11-2004, 09:24 PM

Coat inside the pump cover with some grease and turn the drive shaft while you push down the pump cover. The pump blade will curl back and slip inside

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**OldMerc** · 08-11-2004, 09:44 PM

Does it matter which way I turn the drive shaft? (so the blades will curl one way or the other?) And can I use any old grease? I know some grease and rubber don't go well together.

Sorry for all the questions!

**Rickracer** · 08-12-2004, 05:48 AM

That way the vanes will curl in the right direction. Use Crisco, it'll do you right every time.

**OldMerc** · 08-12-2004, 05:50 PM

But wich way does the motor turn?

Clockwise or counter clockwise? Right now the boat and rest of the motor are about 50 miles away.

**Rickracer** · 08-12-2004, 05:52 PM

**crazy horse** · 08-12-2004, 06:03 PM

Sorry, I didn't make my last post clear for ya

. I was headin to bed when I posted last night. I use a food grade syn. lube on my stuff but that's just because I use it at work and I have cases of it. Crisco works great like Rick said. If you turn the shaft the wrong way don't worry the pump vanes will flip without any damage when the engine is turned over. Direct reverse engines do it all the time

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**Techno** · 08-12-2004, 06:34 PM

Whats with this crisco? I see it mentioned as a wonder lube.
Does anyone even have it in thier houses now with the cholesteral and all the diet madness?

**Rickracer** · 08-12-2004, 07:01 PM

Basically just about anything slippery will work that doesn't attack the rubber. Even spit would work, as long as yer not a snuff dipper and have enough on hand.