View Full Version : Northstar Water Pump Replacment Steps

11-09-06, 02:33 PM
While I was replacing the water pump on my 2000 DTS I wrote down each of the steps. Hope this helps others considering the job. It is really very easy.

If anyone wants to add anything please do so.

2000 Deville DTS Water Pump Replacement

Tools, Parts and Supplies Required

Northstar water pump Remover Tool
10mm 3/8 drive deep socket
10mm 3/8 drive socket
3/8 drive 1 extension
3/8 drive 3 extension
3/8 drive ratchet
drive breaker bar
Phillips head screwdriver
Large flathead screwdriver
Channel Lock Pliers

New Water Pump with o-ring
Housing Cover Gasket (dealer item)

Dex-Cool Antifreeze
Cooling System Pellets (dealer item)

This is one of the easiest water pump replacements I have ever done. Below are the steps in the order I performed them.

Remove radiator plastic cover across top front of engine bay
Remove shield on water pump belt drive. Two 10mm nuts and one 10mm bolt.
Remove 10mm nut holding oil dipstick to water pump housing
Remove air filter and completely remove the air box. Set computer to the side safely. (you will be glad you did this step)
Use large screwdriver to move belt tensioner to release tension and remove belt from water pump pulley
Remove clamp from upper radiator hose and remove hose
Remove clamp from thermostat housing bypass hose (do not remove hose yet)
Loosen 4 10mm bolts with deep socket on water pump housing and let coolant drain
After coolant drains, remove 4 10mm bolts from water pump housing and remove housing.
Place special Water Pump removal tool on water pump cartridge and using drive breaker bar turn clockwise until pump slips off housing.
Remove pump and remove o-ring inside the water pump housing
Clean area good with cloth rag or paper towel
Put clear grease on new o-ring and install in water pump housing
Install new water pump and using special tool and breaker bar turn counter clockwise until new pump snaps into place
Remove old seal from water pump housing cover
Put clear grease on new seal and install in water pump housing cover making sure to insert the fitting inside the bypass hose by the thermostat
Install 4 10mm bolts in water pump housing cover and tighten
Re-install clamp on bypass hose and tighten.
Crush up cooling system pellets and pour inside upper radiator hose
Install upper radiator hose and clamp
Use large screwdriver to move belt tensioner to release tension and install belt on water pump pulley
Install water pump belt shield
Re-attach oil dipstick to water pump housing
Re-install airbox and computer
Mix coolant 50/50% with water
Start engine and fill with coolant watching closely so you do not over fill

11-10-06, 06:17 AM
thanks :)

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11-11-06, 10:49 PM
There is some clown selling these instructions on eBay...thanks for posting here!

http://cgi.ebay.com/ebaymotors/How-to-replace-the-water-pump-on-a-96-Deville-northstar_W0QQcmdZViewItemQQcategoryZ33604QQhashZi tem270053312160QQihZ017QQitemZ270053312160QQrdZ1QQ sspagenameZWDVW

12-15-06, 10:48 AM
I don't think is really all that hard, the only thing I found difficult was to undo the water pump (it required a big round tool to twist the actual pump)

12-15-06, 06:09 PM
That auction is horrible! I wouldn't be surprised if the link is to this board of Caddyinfo! :mad:

12-18-06, 05:37 PM
Just replaced mine 1 week ago.It was quite easy,the pump turned out with no problems,with just a breaker bar and the special tool.Always remember to remove the pump,turn the pump clockwise about 1/4 inch turn.It took me about 2 hours to do,if you take your time it should be no problem.Thanks for the step by step it was very helpful.I would suggest doing it yourself if possible rather than taking it to the dealer (575$).Thats just crazy !!!! :) :) :)

02-09-07, 10:11 PM
I just replaced my water pump on my 94 4.6 Liter. The "special tool" referred to in other posts is a large socket that goes on a 1/2" breaker bar and can be purchased from a local store like NAPA - I wouldn't try turning the pump off/on w/o the socket! Good luck.

07-25-07, 09:31 PM
hmm, i just put my pump in today but didn't use any clear grease. i should be ok i would think...certainly wasn't any left on the old one. I'll add some pictures to this thread when i am completely done...

also just realized i forgot to get my pellets from the dealer today!!

07-26-07, 09:23 AM
Here are some of the pictures I have:

Drain Plug on bottom of Radiator

Water Pump Housing & Cover

Tools with old and new water pumps

09-09-07, 03:14 PM
Good way to save a few dollars.

09-09-07, 03:28 PM
where do you get the tool from?

09-10-07, 11:48 AM
Did you guys remove the oil dipstick piece that is in the way? I can't figure out how it comes out and it is giving me the hardest time trying to get to the bolts.

09-10-07, 02:22 PM
No need to remove the oil dipstick, but should take out the air filter housing and I laid the computer on top of the motor so it was out of the way. Makes it a whole lot easier to get to everything.

09-10-07, 02:25 PM
Mmmk I feel like I'm gonna break the water pump trying to tight it back on.

09-10-07, 02:30 PM
you should not need to take the dipstick out just the air filter assembly and as long as you use a reliable tourque wrench you should be good, make sure everything is seated correctly and not binding or caught on anything, should all slide together nicely

09-10-07, 05:09 PM
Thanks got it out and water pump back in. Trying to figure this tensioner out now.

09-10-07, 06:54 PM
Thanks got it out and water pump back in. Trying to figure this tensioner out now.

Got it all back together and ready to go, pending the new upper hose and coolant in the morning. Wish me the best.

09-10-07, 07:42 PM
Ok I just got done doing a full flush on the coolant and then got it all back together. I actually used one of those $10 flush kits you can get anywhere. They work great and hurt nothing, but they do allow the system to clean out most everything. I remove the thermostat and put back together without one. I then open rediator drain and turn hose on to back flush coupler and then discconnect upper hose and turn motor on. Old fluid will flow out top hose and you run about for 10 minutes and you will see nice clear fluid after that. Then I take coupler off and let motor run for about 30 20 seconds to help push leftover water through motor. Then put everything back together and add bars leak golden seal and dex cool 50/50 and presto nice clean system and no problems ever.

09-11-07, 01:36 PM
I went to pour the coolant in this morning and it all leaked back out. I put in 2 quarts. It feels to be coming from the water pump area, but I don't know what could have gone wrong? I put in a new cover gasket and a new o ring. It's worse than it was before.

09-11-07, 04:07 PM
Did you make sure to use a torque wrench to tighten everything back up to specs and tighten back and forth evenly on the bolts. Does it look to be coming from gasket area or hose area? Worst case if nothing works try a little bit of liquid gasket to help the water pump gasket make a better seal

09-11-07, 07:09 PM
Pretty sure it's coming from the crossover area near the block. I can't get to a few bolts, so I guess i'm putting it back together and calling the dealer to get a price quote in the morning. Ughh :banghead:

09-11-07, 09:57 PM
take it apart look to see if the gasket is messed up and try some liquid gasket on the oem gasket and reinstall. Liquid gasket usually will fill the irregularities. Dealer will charge you $100-$200 most likely to fix with no parts, but sure its something simple.

05-13-10, 08:29 PM
Big thanks to the OP and everyone else that chimed in! I was able to do this repair in my driveway and saved about $400!!! Anyone considering a DIY water pump replacement... go for it!

03-05-11, 06:10 PM
Thanks for the instructions. One thing I'll ad is to use an impact wrench on the removal tool.

My water pump was being very stubborn, I had a 3 foot pipe on my removal tool and it wouldn't budge, plus after cranking on it my removal tool started to clip cock-eyed.

Then I got out my chisel and started to hammer the one tab I could get to, that just mashed the metal, I thought I was really in trouble.

As a last resort I got out my impact wrench. With my full weight pushing the impact wrench tight against the housing (straight) and on max torque, it took about 20 seconds of impacting to get it off... which is about an eternity in impact-wrench land.

My suggestion, try the breaker bar first, but if that doesn't work go right to the impact wrench. It didn't damage the tool, and it probably would have come off easier if I hadn't buggered the one tab with my chisel. If I ever have to do one of these again I'm going right to impact.

03-09-11, 01:11 PM
Actually I just was working on my water pump on a 94 4.6 engine. My pump was installed so tightly and or corroded in there that one or two of the slots on the pump started wearing off so the removal tool tabs were just sliding off! I finally got my impact wrench in there and the hammering action of the wrench was enough to carefully pop the tangs of the pump out from under the retaining tabs of the housing. That was really annoying.

03-09-11, 02:45 PM
Also, is there really an orientation for the one tang on the pump that does not look like the others? I just noticed that it looks like a coolant pass through hole is on the pump housing and if you put the unusual tang at the 7:00 O'clock orientation that the manual says to then that pass through hole is straight up and down. Which would seem to make sure that gravitationally the cooling fluid would run through that hole better.

Well my real question is how do you know that you have the unit seated all the way?

05-04-11, 11:28 PM
I am wondering the orientation of the water pump as well. It came out with a small (12") ratchet easy enough, a few taps on the ratchet got it out. However, I cannot get it back in - even with a 24" breaker. I don't want to take an impact to it until I know its in the correct orientation. I will try tab w/o mini tab in 7:00 position and report back.

05-05-11, 11:51 PM
DO NOT use an impact to install it. :tisk:

2002 Devile DTS
05-25-11, 07:59 AM
Has anyone came up with an answer to the orientation of the water pump tabs for installation?


05-26-11, 03:18 PM
Just take note of the tab positions of the old one you remove.

03-31-12, 03:38 PM
Thank you for the great write up on changing the water pump. I just finished in my 2004 Seville, took 3 hours, but that included lunch, two trips to the auto parts store and a half hour of trying to unseat the pump while turning it counter clockwise, Doh! Thanks again for the instructions, Advance and Autozone did not loan the tool so I bought one from Advance for $30, the water pump was $45 and the seal was $4.

01-11-13, 03:02 PM
I wonder if a note should be made about changing the pump housing/cover to update to the new style with that awesome picture that shows the two styles

and also it should be noted that the thermostat housing gasket also has to be changed to the thicker style (from #3522676 to #12574478) when upgrading to the new pump housing/cover

or maybe just find a way to merge this thread and this one: http://www.cadillacforums.com/forums/cadillac-deville-1985-2005-including-1985/209553-how-water-pump-removal.html

01-17-13, 03:36 PM
New w/p housing cover and gasket - designed to stop delayed leaks.

The Frugie
07-31-13, 08:16 PM
I wanna thank ipncjh1 and everyone who has contributed to this thread. It's been a great help in replacing my water pump. I've run into a hangup though. I can't get the new w/p on. It took me the longest to figure out the correct orientation (it's 1 o'clock, not 7 o'clock like the ACDelco instructions said). But even after I figured that out I still couldn't screw on the new pump and ended up bending the tangs.

So I bought another w/p and tried screwing it on without the o-ring. Finally it fit. But I can't leave it like that. So what should I do, get a thinner o-ring, use a razor or something to scrape off part of the o-ring I have? Has anyone else run into this problem?

08-03-13, 01:19 PM
Did you lube the O-ring with raw coolant ???? - and it MUST be installed as-is - no scraping or resizing is possible or desired......... and did all the original ring come out of the water pump housing ?

The Frugie
08-05-13, 04:42 AM
I finally got it in. It turned out some of the old o-ring was still on there. My aunt and her husband were visiting and he took a look at it. The first thing he asked for was a flat head screwdriver. I don't know why I didn't think of that. I scraped off as much as I could using a razor, steel wool, and even my finger nail. But the screwdriver ended up being perfect for the job.

09-18-13, 09:38 AM
I'm having a BEAR of a time getting the 4th, bottom right hand bolt out of the WP cover. There's black covered wire or something impeding the socket going on straight. Any suggestions? 98 DeVille. Thank you!

05-04-14, 12:47 PM
Just did mine. Surprisingly easy. The special tool worked like a charm. The hardest part was cleaning the o-ring area, and also cleaning the housing gasket area, then replacing both seals.

08-13-15, 07:03 PM
I just wanted to add that for my Cad a 01 STS this was a lot more difficult than the standard model described here-at least in my case there was some kind of EVAP canister in the way, wasn't too much more difficult but different-I'm fortunate to have medium sized hands as I could just barely fit my 10mm wrench in there but I got it- sometimes working on my head but you can do it- if your having problems taking off the pulley cover you gotta take off the EVAP canister first- there's also a screw that holds a plate that holds onto the dipstick/evap device you need to separate- it's kind of hidden in the bottom/middle of the plate.

What was really difficult and no one mentioned this was lining up the waterpump to go back- some folks said 7o'clock some on the internet said 1PM, apparently there BOTH right depending on the model but the sure fire way to line it up is you'll have a tab on your waterpump with a open circle on it different from the other tabs- if you look at where the waterpump is supposed to go- there will be a small circle cropping out about the same size as the tab's circle-THAT is where it's supposed to go.