ddahlgren

How long to change one on a 91? Car is on jack stands if that makes a difference, at least it will be easy to remove lower hose and drain coolant.
On a second note does anyone know the diameter of the stock crank pulley for the belt? I want to make sure there is not an under drive one on it.

I see take off belt remove air pump stuff and go for the bolts from there. I am planning on hitting every bolt I can see with PB Blaster a couple times before I even start.
How much noise does the air pump make if I don't hook up all the hoses or run a tube between the inlet and out of it?

I have available locally rebuilt pumps std for around 38 and HD double that both in GM housings by the pics and both aluminum. There is no way going for new or after market for 150+
I see it as something that whatever came on a base coupe lasted 75k miles and 26 years for me to duplicate either the miles or years is impossible at 66 years old.

Am I missing anything? Will obviously put on a new lower hose while drained and on stands.

billschroeder5842

Somewhere between 3 and six hours. Why the range? Everyone has different skill levels, methods of working and distraction factor. I am pretty handy but my projects take twice as long because while working on the "main project" I tend to notice sometime else that needs attention.

"Well, as long as everything is ripped apart, I might as well do.. (insert here).

ddahlgren

Yeah I get it at times my attention span is about the same as a fruit fly

HAD2HAV2

Buy a set of blue Felpro gaskets. I wish I had but will the next time.

You may want to replace the O-rings for both the fuel lines if they must be disconnected like my 88 L-98.

65Z01

Hey, don't sell yourself short, likely you wouldn't want to do the job again at 92...

ddahlgren

Or 72 either

ddahlgren

On the rebuilt water pump market who makes something worth using? NAPA had 2 that were done on GM castings that looked good and very reasonable but not available even to order and wait. Carquest makes a std duty and heavy duty that are on new castings but machined with a straight inlet for the lower hose and no bead to seal the hose. There are some new pumps claim to be made by ACDelco on auction sites with no visible casting numbers so screams Chinese to me. Edelbrock and Weiand are priced out of the question for a car that gets under 3k miles a year on the street. I don't think I am up for looking for bearings to rebuild my pump even though I do have a press and fixtures.

I am open for ideas of known works well solutions.

Whaleman

I changed my opti and water pump and plugs and wires in my 96 3 months ago. The pump I had was a replacement. It is the more expensive AC Delco. It was working fine but I changed anyway. If you want it you can have for shipping. Dan

ddahlgren

Thanks for the offer I appreciate it nut have a L98 in a '91 so different cooling system entirely.

Whaleman

Anyone else want it just PM me. Dan

ddahlgren

I am wondering if just running the car will make the water pump bearings loosen up. It has been sitting for close to 2 years. It has good anti-freeze in it and don't remember the noise when parked. I am thinking of just letting it run for a 1/2 hour a few times while on stands to see if it calms down or if I am all wet here.

BrianCunningham

Be sure to use sealant on the bolt that goes into the waterjacket

383vett

What are your symptoms? Is it noise, or overheating? Is it binding? Take the belt off and spin it by hand. Is it free? Leaking?

Tom400CFI

It's easy. All you need to do is take all this off to get to it!

FASTAZU

One hour and 2 hours looking for tools and where I set the removed parts

AgentEran

I just organized all my tools this weekend due to this issue!

383vett

And another hour looking for missing sockets.

ddahlgren

It makes noise and have it 50% apart to the point I can see the pulley and it is loose with a pulley that will at least 1/8 inch corner to corner so yes the bearing is shot it does make noise but does not leak yet so off it comes. I do know the air pump stuff is never going back and will make a bracket for the idler pulley to replace it. Good time for a few new hoses too even though probably going to sell the car. It has an under drive pulley on the crank and a little larger one than stock on the water pump. I have I think a larger one for the crank and smaller one for the pump that are supposed to be stock. At lest it will get a fair chance at cooling and charging the battery. A/C might get better along with PS with all running at correct speeds.

Cute pic in the post that makes it look easy to get to as there is a lot more stuff on mine between me and WP.

ddahlgren

I never thought buying a water pump could be so difficult. Napa has nothing worth owning as the have 2 cast iron pumps and cardone pumps that don't even have a lip to retain the lower hose. Rock auto seemed equally disappointing and part geek is very vague with specs to see if a reverse rotation with 3/4 inch shaft to center the WP pulley. Weiand and Edelbrock are wildly too much money for a street car, especially one I am thinking about selling. If anyone has a reasonably priced source I am up to try and at least look.

It needs to be aluminum reverse rotation with a 3/4 shaft for an L98.

I am up for ideas and have no problem if the person with the good idea is affiliated with the seller!

cdm747

I bought mine from Summit Racing, their brand part number SUM-312635 . I haven't installed it yet but should be the right one. About $63. Mine is an 88 but shows the same for 91.