ST1300 water pump damaged?

[Turbine2]

Hi everyone,
2005 ST1300 with about 67k miles on the clock. I had a recent issue where the t piece at the top of the radiator broke while I was at speed (about 70mph) and was probably driven for about 1/4 to 1/2 mile spraying steam behind. I did see the temperature gauge hit the red but I killed the engine pretty quickly and the temp pretty much immediate dropped back to 3 bars.
Got the bike recovered and the garage replaced the t piece, looks like they added about 2l coolant to it.
I road it to work in the morning and all appeared well, but on the way home I started to slowly overheat. Air temperature in the morning was about 18C, about 26C in the afternoon.
I can hear the fan running, so I know that is ok. I have taken the plastics off and looked for leaks and at first there was nothing obvious. I added about 1/4-1/3l coolant to the reservoir as it was low and started the engine again. All appeared well until I started to rev the engine, at which point I started to see a liquid pooling under the bike.
At idle it appears fine, it’s only when revs are increased that I think the water starts to leak. I have looked at https://www.st-owners.com/forums/threads/st1300-water-pump-weep-holes.166819/ and it looks like the leak is from the square hole, but I can also see it from the crease where the covers meet.
What thought do you have? Something else failed or something need tightening?
Thanks in advance.

 

[SMSW]

Do you mean the T on the right front side of the engine? First thing I would do is pull the fairing and check the hose clamps an hoses, especially the overflow hose from radiator cap area to expansion tank. If they put in a new plastic T and overtightened the clamps, that could be cracking. You should change it to an all brass T. I would also find out what kind of anti freeze they used, and check when your AF was last changed. It should be changed every two years (YMMV), and must be a silicate free type. More than a few of us run Honda Type 2 - available at their car dealerships for around $20/gal.

I would not expect the overheating to damage the water pump, maybe the thermostat? (That should not cause leaking, though).

 

[Turbine2]

Thanks Smsw,
Yes, that’s the T that broke and they did replace it with a brass one. I’ll check the antifreeze but I think it was a silcoline branded one.

 

[Oldbikefixr]

Not trying to offend here by any means. The hose in your photo was due replacement years ago. Chances are all of them, and the clamps, are in similar condition. Given the bike is 16 years old or so, I would remove the bodywork, clean up everything and replace all the hoses and clamps, thermostat and cap, coolant.....then watch for waterflow/leaks before replacing the water pump.
But...this is just me. OCD enough that I don't like to revisit problems on an inconvenient basis.

 

[SMSW]

But...this is just me. OCD enough that I don't like to revisit problems on an inconvenient basis.

We all have a choice to decide when to do preventative maintenance or let the bike decide. Unfortunately, the bike's decision is usually in the middle of a long trip far from home. Stuff does not usually break when the bike is sitting in the garage.

 

[Turbine2]

Yes, you’re right. I’ve got the Tupperware off at the moment and plan to do some cleaning anyway.
I was hoping that it would be something simple, I just can’t see why the water would come out there.

 

[dduelin]

Yes, you’re right. I’ve got the Tupperware off at the moment and plan to do some cleaning anyway.
I was hoping that it would be something simple, I just can’t see why the water would come out there.

It’s probably not the water pump but you will find out when you clean it up.

The ST1300 weeps, seeps, and leaks from a myriad of hose connections in the vee of the cylinders. Honda provided a drain channel but they weep a long time but not enough to drip. The coolant blows around and gets everything grimy but it evaporates from the heat under the fairing. The weeping goes on and on until it’s enough to drip on the floor 65,000 miles is about right to notice but it’s been leaking for a while just not enough to drip on the floor. It’s time to catch up on some deferred maintenance.