Write-Up: Water Pump (Series II SC)

They're thinner than the water jacket bolts and in the past (granted - they were 40 year old bolts), I've had them snap on me. Nothing is worse than having that happen - but especially on a FWD car given the room to work with. I'm just saying , be cautious and don't over torque them. Something else I've noticed is that since I've replaced all the pulleys (minus the HB) and tensioners, my Riv doesn't have the shimmy at high speeds like it used to. Coincidence?

I too had to perform the water pump replacement earlier this month. Interestingly, the pump failed the very day after replacing the radiator, hoses, and coolant. Mine started leaking badly late on a Monday night - I lost more than a gallon of coolant on a 40 mile drive. Obviously, this repair could not wait.

First things: I didn't want to get under the car, lift the engine, nor remove the side mount bracket. My reasons: started the job at 12:30am, and needed to get this finished in a couple hours, hoping for some sleep before waking up for work at 7am. I know, it wouldn't be easy, but I had to try.

What I found out is, YOU CAN swap out the water pump WITHOUT removing the mount. But the power steering pump does need to come off, which can be done from top side. Here's a pictorial of the process:









Here's how you can tell a bad water pump:



PS - I had no issues breaking screws. All came out easily with a box head wrench or 6-pt socket.































That's pretty much it. I actually took about 3 hours, because like some others I hadn't done a water pump on a Riviera before, so took my time. All-in-all, not too bad.

No leaks or other issues after 3 weeks!

Great wright-up. I just did my WP a few weeks ago. 2 days after doing a coolant flush i walked into my garage to find a puddle under the car (had to call into work).
My guess is the weep hole gets clogged over time with debris and flushing everything cleaned it up allowing the leak to reappear.
I had to get a crappy valucraft part to hold me over until the acdelco one came in the mail. Anyone know the difference between the "aftermarket design" and "OEM design" price differences are pretty large.
I still need to swap out my valucraft for the acdelco one. I just dont trust the autozone parts to last more than 6 months.

I usually don't skimp on parts, especially critical ones like this. But having had water pumps go out on most all my other cars, I bought a spare pump back in early '07 to keep around in case (when) the Riviera's failed. I think I found it at Advance Auto for $35. The brand name is "Signature". I have no idea how good or bad it is, but I do know our water pump is a very simple machine with a very simple job. Imo, it's hard to screw up the design unless they used an inferior bearing.

Good news is, I was in fact prepared for the inevitable, although I never thought it would be almost 5 years later than expected. More good news, if I ever find out this part wasn't of good quality, swapping in a new (AC Delco) unit should be a breeze now with the modified screw flange behind the motor mount.

If I were you, I'd just check your pump every year. It'll probably be all right. If not, maybe have an AC Delco unit on your shelf, ready to install at any time!

Hubby is tackling WP replacement right now, and he can't get over how poorly GM designed everything under the hood . . .ugh! This write up has been helpful and thanks!

LARRY70GS wrote:

The procedure is the same as this write up for belts and pulleys. I remember reading in this write up about some guys reporting leaky pan gaskets after jacking the motor by the oil pan flange. My friend Steve (71stagegs) told me he used an area of the block just forward of the pan. I took a look, and sure enough, I was able to use a narrower piece of wood that fit right in there.

Do you have a better picture of where you supported the engine? I am having trouble finding a good spot to support the engine. I looked by the ac compressor and I didn't see any area to support the engine on the block. Did you have to remove the plastic shield that covers the cam sensor? I saw a spot below where the dip stick goes into the block. Would that work? The AC compressor bracket had a good spot, but I am worried that it would be too much weight on that area.

The contrast in that picture isn't the greatest, but if you look past the forward part of the oil pan, you will see a small section of the block, and that is what I used. I just used that thin piece of wood. Look carefully at the picture. You can see the oil pan flange and bolts. You don't want to support the engine weight on the oil pan flange. One of my friends made that mistake, and bent the flange, which resulted in a leak.

AA wrote:

I saw that when I was under there but wasn't sure if that would work. But if that works then great!

I think there are two areas of block that could work. Use the one closest to the water pump.

AA wrote:

I think there are two areas of block that could work. Use the one closest to the water pump.

Here are two pictures that I took of the area closes to the water pump.



Compressor Bracket View


I can't find a good place down on this end of the engine for a support. I guess I'll try to use the transmission spot that you posted above.

It looks like the spot I used is covered by the CPS cover. Don't remember mine extending that far. There is nothing wrong with supporting it under the balancer either. Done that many times with my 455.

LARRY70GS wrote:

It looks like the spot I used is covered by the CPS cover.  Don't remember mine extending that far.  There is nothing wrong with supporting it under the balancer either.  Done that many times with my 455.

I will try to use the location that AA posted and hopefully it won't be to far from the water pump.  If that doesn't work, do I just put a block of wood on the bottom of the balancer in the top of my first picture?

Also, do I need to put RTV on the metal gasket version?

Or, you could change out the pump without needing to remove the mount, if you modify one of the bolts for easier removal.

AA wrote:

Or, you could change out the pump without needing to remove the mount, if you modify one of the bolts for easier removal.

I need to change out the idler behind the bracket, otherwise I would give it a try.

For that gasket, I wouldn't use RTV. Looks like it includes a flexible layer that is self-sealing.

98riv wrote:

AA wrote:

I saw that when I was under there but wasn't sure if that would work. But if that works then great!

I tried using that location and it didn't work. I may either buy an engine hoist or just using a block of wood on the oil pan bolts and jack it up from there and change the oil pan gasket later if needed.

Oil pan bolts should work fine, or you can prop it from under the crank pulley as Larry suggested. The engine really isn't that heavy compared to the rest of the car. As long as you're not bearing the car's weight + supporting the engine there shouldn't be much problem.

AA wrote:

Oil pan bolts should work fine, or you can prop it from under the crank pulley as Larry suggested. The engine really isn't that heavy compared to the rest of the car. As long as you're not bearing the car's weight + supporting the engine there shouldn't be much problem.

I got it changed this afternoon. I ended up using a piece of a 2x6 and put it under three of the oil pan bolts. I forgot how much a pain in the butt it is removing the mount and the idler behind it. The new water pump looks like a better design than the oem pump.

Thanks for the excellent write up and pics on changing the water pump for the series 2 engine.
I have the GM shop manual and it was no help; made no mention of the PS pump pulley in the way.

I just completed mine (97 NA) yesterday and it only took a couple of hours and $35. I would only add a couple of tips for the next guy:

No need to raise the engine. You don't need to remove the motor mounts. I completed the whole job in relative ease from leaning over the passenger side fender. It's a little tricky to get the fourth small bolt out of the bottom of the water pump (because you can't see it) but with a little finesse, you won't have too much trouble ratcheting it out.

It is necessary to remove the PS pump. I tried everything around that, because it's a little difficult to line the holes up and put back. You can't just remove the top bolt and spin it out of the way because a stud hits the back of the PS pump pulley, so you have to take both bolts out to move it aside.

Re-use your hardware? My bolts were pretty gummy, but after a few seconds on the wire wheel they worked like new. Just be mindful to not over torque them.

The new pump that I purchased from NAPA was only $35 and was of excellent quality. It also came with a metal gasket that required no additional silicone.

She's back on the road and I was pleasantly surprised of the ease and low cost of this repair...

So I did the water pump in our '98 Riv today and took a slightly different approach to not removing the engine bracket or supercharger idler. Call me a maniac or a genius...  I cut the end of the old water pump off around the bolt with a sawzall, and then on the new water pump I cut a notch in the bolt hole just big enough to slide around the bolt. It's aluminum and cuts very, very easily! So basically, we never removed the front bottom bolt. Worthless without pics, right? So here you go!
The old and new pumps below:

A closeup of the notch in the new pump below:

And a pic of the bolt we never removed below:


It should go without saying that this eliminates any chance of a core refund, so spend the $5 extra to get the new pump instead of leaving a $5 core deposit...
Also, I had to use a long sawzall blade to get all the way down there and have a helper hold the pump still. The sawzall blade is called "THE TORCH" and I had to be careful not to damage anything else around the standoff, but it took an extra 10 minutes to do and will save even more time if the pump ever needs to be replaced again! (IF we remember that we did this...) It goes right along with cutting the spacer to make belt changes easier!

LARRY70GS wrote:

The long ones go through water, so after cleaning them, I used some teflon sealer on the shanks, and anti seize on the threads.

I'm dubious on this. I didn't see any signs of that stuff on the bolts I pulled, which are fine after 22 years. What is the teflon sealer supposed to do, protect the bolt shanks from rusting? Is it going to stay on the bolt shanks with water flowing over it? I'm concerned that it is going to wash off and collect in the radiator.

Jack the R wrote:

LARRY70GS wrote:

The long ones go through water, so after cleaning them, I used some teflon sealer on the shanks, and anti seize on the threads.

I'm dubious on this.  I didn't see any signs of that stuff on the bolts I pulled, which are fine after 22 years.  What is the teflon sealer supposed to do, protect the bolt shanks from rusting?  Is it going to stay on the bolt shanks with water flowing over it?  I'm concerned that it is going to wash off and collect in the radiator.  

It's been so long since I did the water pump Jack. Can't remember where I saw that. I know on my 70 GS, some of the bolts go through water and I think the FSM tells you to coat them in something they call "Perfect Seal" The anti seize is way more important.

There was no anti-seize on the bolts I took out. The part they bolt into (timing chain cover?) is aluminum, isn't it? Can the bolts rust into aluminum? Mine didn't rust after 22 years. They had some deposits on them, but they came out easy enough.

I did see a strip of what looked like threadlocker on my bolts, so I did put some threadlocker on. That makes more sense to me, I imagine a water pump has to have some vibration to it, and the torque setting for the bolts is pretty low. If yours haven't come out, then I suppose it's enough, and the threadlocker was just an extra bit of security.

JR,
I wouldn't worry about it. If it doesn't need changing within another 20 years you won't need to be bothered by any seized or leaking bolts.

The teflon goop is to seal any bolt that enters a water jacket. But your thread locker should do the same.

The anti-seize helps with dissimilar metal corrosion. i.e., Steel Bolt and Aluminum housing.
Again, I wouldn't take everything apart. Just continue with what your doing, fill the system and after it gets hot look everything over real good to be sure you don't have any drips or leaks from the gasket area and all the bolts.

Happy Motoring.
Rick