water pump on LT1

last fall I went on aggressive flushing campaign in order to get the heat working better. in the process I developed a leak dead center in the front of the engine. I assume it is the water pump. How difficult is it to replace the water pump on the LT1? does the opti-spark have to come out?

any tips or tricks?

I'd check the hose connections at the pump first for drips, unless you see coolant leaking from the gasket or shaft.

It's not difficult to replace the pump, and it's not necessary to touch the Optispark in the process. Even I did it without a screw up.

Does yours have the clutch driven metal fan or electric fans?

dmg4 wrote:

I'd check the hose connections at the pump first for drips, unless you see coolant leaking from the gasket or shaft.

It's not difficult to replace the pump, and it's not necessary to touch the Optispark in the process.  Even I did it without a screw up.

Does yours have the clutch driven metal fan or electric fans?

I believe it has both fans, I know it has the engine driven fan. pretty sure it is not a hose, but of course I will check before i order parts.
I am glad I dont have to remove the opti-spark.
I will check it out more when the weather warms up.

It's pretty easy. If your Opti cap and rotor has NOT been replaced, 145K would be a good time to do it. just the cap and rotor. It's right there once the water pump is off.... just saying

Sprocket wrote:

It's pretty easy.   If your Opti cap and rotor has NOT been replaced, 145K would be a good time to do it.  just the cap and rotor.   It's right there once the water pump is off....  just saying

thanks, I cant remember if I did that or not.

Sprocket wrote:

It's pretty easy.   If your Opti cap and rotor has NOT been replaced, 145K would be a good time to do it.  just the cap and rotor.   It's right there once the water pump is off....  just saying

Let sleeping dogs lie,.. i'm just saying

frederickflintstone wrote:

Sprocket wrote:

It's pretty easy.   If your Opti cap and rotor has NOT been replaced, 145K would be a good time to do it.  just the cap and rotor.   It's right there once the water pump is off....  just saying

thanks, I cant remember if I did that or not.

I'm pretty sure you'd remember if you did.
if you do pull the WP, make sure you replace the seal.

jasonlachapelle wrote:

frederickflintstone wrote:

Sprocket wrote:

It's pretty easy.   If your Opti cap and rotor has NOT been replaced, 145K would be a good time to do it.  just the cap and rotor.   It's right there once the water pump is off....  just saying

thanks, I cant remember if I did that or not.

I'm pretty sure you'd remember if you did.
if you do pull the WP, make sure you replace the seal.

what seal are you speaking of?

[You must be registered and logged in to see this link.]
waterpump and optispark seal. Found in Felpro timing cover gasket kit.
[You must be registered and logged in to see this link.]
homemade tool to install seal


you can watch this video to see how it's done: http//www.impalassforum.com/vBulletin/34-engine-problems-maintenance/250397-96-impala-camshaft-optispark-seals-replace-video-3.html

Having trouble freeing the old water pump. I'm pretty sure I have all the bolts out, but it's not budging. Is there a hard to spot bolt somewhere? I am using the new pump to identify where the old bolts should be.

Going to be late for work tonight already.

At the top of the photos you see two non-threaded locating pins. These are needed because of the way the pump is driven. They may have become corroded. Try using your favorite penetrating oil elixir on them.

I think I found the problem on live. There is an air pump bracket I was unaware of that needs to come off. Will not get back to it till saturday. Hope the u-tube guy is right

Yes, you need to pull the air pump bracket. The stud it is mounted to is also a bolt for the water pump. There are THREE on each side.

New pump was driving me crazy. Turns out one of the alignment holes for the pins was undersize. Trying to find an 11/32 drill bit to enlarge it. Guessing at the size. the old holes were between 5/16 and 3/8 as measured with drill bits. Neither bit fits in the small alignment hole. Gasket cement is all dried up, so I guess I will be using form-a-gasket instead.

Was planning to do cap and rotor while I was in there. No longer have the time for that.

Finally running again. Wagonfest odds are improving. Broke a vacuum connection but it's alive again

I know not the issue you had, but adding in for others that are having an issue getting the WP off after removing all the bolts. My 94 sat for a few years and where the drive gear went into the WP, it corroded together and froze. I ended up breaking the spindle on the drive gear getting the old pump off (too much crow bar) and had to take off the timing cover and replace the gear (someone on ISSF was nice enough to mail me one for free). So be careful!

One of my problems was the holes for the alignment pin were too small and had to be drilled out. It took a long time to figure that out