Lexucan

Scenario:
I took my ES300 to a local shop last week to have them drain the cooling system (no flush) and then add new coolant (I have no area available to do it myself).
Two days later, while sitting at a traffic light, a noticed that the temp needle was climbing and it started to overheat. When I checked the coolant level I discovered that it was down about 2 litres. I figured maybe the shop hadn't bled the air out enough and didn't fill the system to capacity and so I topped it up myself. Next day I checked the coolant level again, and it was down another litre. I also now noticed that there was a slow coolant drip coming from the right side of the engine somewhere. I couldn't tell exactly where it was leaking.
So, the following day as soon as the shop opened, I dropped it off so they could find out where the leak was originating from. Note: there were NO coolant leaks before they did the drain and fill, so I suspected they forgot to tighten a hose clamp or something.
A few hours later I get a call from the shop. They tell me that they traced the leak to my water pump. I said, "hmm...... so, you did a coolant drain and fill last week and now my water pump is shot? Sounds mighty conincidental!"
They disavowed any responsibility for the pump leak but offered to replace it, and my timing belt at the same time for $962.00 !!

Question:
Could they have willfully or inadvertently damaged my water pump during the coolant drain and fill?

Conspiracy theory:
They get a 13-14 y.o. car with lots (400K kilometers) of mileage on it and think to themselves, "hey guys, this old thing is apt to start leaking on its own pretty soon anyways, so let's just help it along and make some extra money".

Adding insult to injury:
They charged me $52 to diagnose the problem when I took it back to them to be checked after I noticed the leak.

Lexmex

I could not comment a lot more without seeing your ES, but I can tell you that when I do a coolant/flush change, more often than not when I check the morning after I do it, I sometimes have nothing in the coolant reservoir and I had to exactly what you did in topping it off. After that, everything is ok.

Now whether there was a leak or something else that is a different story.

Quite recently, I was driving a 1996 Dodge Caravan that overheated and the water pump was shot after that. We could not find any leak, but the coolant/water had literally disappeared and we had been quite vigilant on checking this vehicle (due to prior problems) every week. I even looked back up the road just after this happen for any trace of a leak and nothing.

Just a side note, the thing with timing belt and these engines is that when it comes time to change the timing belt it is easier to get at the water pump at that point in time. By my count, if this has been changed on time at 90K miles, you are about 30k miles away with the conversion from km or close to 50k km.

Lexucan

Thanks for the input, Lexmex. And you are correct. I will need to get the timing belt changed after another 30-50K kms or so. However, the issue of the water pump crapping out immediately following the coolant drain and fill that the shop did last week is just a little too coincidental for me to accept.
It is therefore my theory that they either "accidentally" did something to cause the pump to leak, or as I speculated earlier, they somehow forced it to start leaking (either during the drain and fill or when I took it back to them to find the origin of the leak) so as to drum up some future business.

Lexmex

It also depends how they performed the coolant drain. They could have pulled a hose to do it. On my RX300 (and I know we have similar engines depending on year), they have certain drain valves. Late last year, my uncle and installed the TRD low-temp thermostat. We completely forgot about the coolant drain (though we did have extra as we planned to replace it) before we removed a certain hose in order to get at the thermostat. The coolant came all over the place and my uncle was VERY CAREFUL to make sure when we put that hose back on that it was clamped well. He told me to check it after I ran the RX up and down the track. No issues.

However, if these guys had done it via pulling a hose as opposed to using one of the valve drains, I could see where they might have screwed up. On a vehicle with that many km, it is possible that pulling off one of the clamped down hoses and then putting it back on, loosened a fit that had been there a long time just enough to cause a leak.

Still, this is not the preferred method and using the drain valve should be used. Again, we do not know which method they used.

Seeing exactly where that leak is coming from would help.

Lexucan

When they called me yesterday to give me the news that my pump was leaking, they said that they could not be held responsible for the leak as they did the drain and fill by draining the coolant from the radiator - loosening the lower radiator hose. So, by their own admission, they did not drain the coolant via the two valve drains.
Before I got the drain and fill done, I asked them if their techs had access to the factory service manuals for my year and model. I was told that they did. I even went so far as to supply them with a copy of the FSM on CD-ROM when I dropped off the car so as to be sure that they did. When I picked up the car after the coolant change, I found the CD-ROM laying on the passenger seat of the car.
So, what you are suggesting is that by monkeying around with radiator hoses instead of draining the coolant the proper way (i.e. via the valve drains) they might have weakened the connection to the pump and caused it to begin leaking. This sounds quite plausable to me.

Lexmex

Let me know how it turns out.