You know what a new water pump costs to do with the timing belt? $65. To do by itself, $65, oh and a Saturday morning doing something I enjoy anyhow. Where's the savings?

Do you replace your valve springs when doing the timing belt? Why not? You have the head cover off and they do fatigue over time. Do you do a brake job every time you rotate your tires? Why not? Half the labor is already paid for in jacking up the car and removing the tires, and brakes do eventually fail. The point is that the replacement interval for timing belts and water pumps are not the same. Just because something is easy to replace when doing another repair is not a reason to replace a perfectly good part, unless you're the mechanic making the markup and additional labor for removing 5 bolts and setting a new water pump in.

And yes, quality coolant replaced at regular intervals will in fact extend the life of every component in your cooling system including the water pump. Do you think corrosion inhibitors last forever. They are consumed over time as they do their job.

RAAM, you say I don't know what I'm talking about? You have no idea. Stay in school. Read up a little bit on tribology. And I'm not talking about Wikipedia. With proper lubrication there is essentially no metal to metal contact and no wear on those bearings and they will last a very long time, much longer than a wearable part such as the timing belt.

There's really only one way to know for sure, and that's to see the data on MTBF for Civic water pumps, which none of us have access to. Without that, its just speculation on my end and yours, but as I said earlier, there's no savings for me in replacing working parts.

 

hmm
then why do you replace the timing belt?

 

Trust: You've entirely missed the point I am making. I replace the timing belt because:

1) The timing belt will certainly fail in the time that I plan on owning the car.
2) It is a wearable component designed to be replaced periodically (like fluids and filters).
3) The manufacturer recommends that it is changed as preventive maintenance.
4) And a failure is catastrophic to the engine.

None of these reasons are true of the water pump.

Look, you all are entitled to your opinion, but so am I. The guy who started this thread asked for advice and I gave him mine. That's fine if your advice is different from mine but I wouldn't replace a part that is functioning, that cannot be reasonably expected to fail in the life of the car, and that is not recommended to be replaced by any service bulletin or service schedule from Honda. Lets face it, the concept of replacing the water pump with the belt is a cash cow for the mechanic, 10 minutes of work and the bill is jacked up by $125.

A water pump should not be periodically replaced as preventive maintenance. Don't take my word for it, that's the recommendation of the engineers that designed your car and wrote the service manual. I think they know a bit more about it than you and I, and your dealership mechanic for that matter.

If anyone can produce MTBF data on at least 30 Civic water pumps, or show me a service bulletin or service manual schedule from Honda (the manufacturer not your dealership) that lists the water pump as a service item then I'll gladly change the water pump next time I do the timing belt. But as it stands now, I've changed the belt twice and never done the pump. The car has 177K miles on it and I don't expect to own it more than a few more years, the probability of having the pump fail while I still own the car is low enough that I'm glad I didn't spend the money on two pumps.

 

There are just some differences of opinion on this matter. Your opinion is in no way shape or form invalidated by this discussion. The service manual says to inspect the water pump when the timing belt is replaced. I assume this means checking for leaks and whether the sprocket spins freely. I replace my water pump when I do the timing belt job because I don't think $65 is an excessive price for a water pump and I would be angry with myself if I needed to remove the dreaded crankshaft pulley just for a leaking or failed water pump.

 

Sure, if you have the money go ahead and replace the pump if it makes you feel better. Nothing wrong with that. It depends on the situation. But you should know your mechanic's advice is extremely biased. If you're low on cash skip the pump. But in terms of an "insurance" policy it's pretty lousy. I pay $135/yr for $500K of term life insurance. Over the next 5 yrs the cost per dollar of coverage is $0.00135. For my homeowner's insurance it's $0.021. Now for your water pump. Let's say the cost with the belt is $100 and the benefit is not having to pay the $265 down the road to do the pump alone. The cost per dollar of coverage is $.37. That ain't cheap insurance.

 

honda says inspect the water pump.

 

Given that I do all of my car work, save wheel balancing and alignments, your accounting method fails to factor in how much I value my time. Hence, my cost per dollar of coverage for replacing the water pump is a much better deal than your estimate suggests.

 

I didn't even think of that.

So I guess an example would be: To work on the car you'd have to take a day off and do it. But say that the money it would cost to get it done at a shop is less than the amount of money you would make working in the time it would take to do the work yourself.

Let x = the money you make in an hour
y = the amount of money the shop would charge
t = time it would take you to do it.

If x•t≥y, it would be more cost effective to get a shop to do the work.



So related to this situation:
Let t = the amount of time that it would take to disassemble the components a second time + the cost of the water pump
x = the amount of money you make per hour
y = the additional cost of getting the water pump replaced when you had changed the timing belt

If x•t≥y, it would have been smarter to replace the water pump when you did the timing belt

 

Even in this scenario, it is still more cost effective for me simply to replace a seemingly "good" water pump when I do the timing belt job because you must also factor in the cost of the enormous personal inconvenience of taking the car to the shop in an emergency situation, waiting for the repair to be completed, and then picking up the car. You might even need to factor in the cost of having the car towed to the shop. Clearly, 96Cex's accounting method is way too oversimplified.

 

If its far more expensive for you to do the work yourself because of your time then why would you do it yourself?