Water Pump Leak Unusual

[marc11]

Hey, new here and of course I have a problem and need to ask for some help, I will make up for it promise, and sorry to start this way....

New to me 2004, about 83k miles, purchased in Florida and rode it home Sunday; hit lots of traffic as you do on I-95 and smelled coolant, unsure if it was the bike or cars around me, but in any case made it home with no drama. In checking the bike over I noticed the overflow was low, which is odd/not odd, but then noticed a small puddle of coolant on the floor.

Cleaned the area well and ran the bike, it is not coming from the weep hole and not coming down from the top of the engine V as far as I see, starting the bike I can see it is seeping rather quickly too from between the water pump cover and the clutch cover, right at the seam.

I am inclined and beyond hopeful it is just a failed o-ring seal between the water pump cover and the clutch cover. Wondering if anyone has seen this before and have any thoughts?

 

[Oldbikefixr]

Check the long hose that runs from the thermostat housing back to the overflow tank first. Then all the hoses you can reach for evidence of water leaks. Some owners simply don't bother to look under the fairings of these bikes. Remove the lower cowl and forward piece just behind the forks. Start it up, pull up a stool and watch.

 

[970mike]

It could be the 0-ring behind the water pump cover, I would clean it up and try to locate the leak before replacing any parts. At the age of the bike it maybe time to replace all of the hoses and
o-rings anyhow. Good luck.

 

[Mr.E]

EDIT: A good idea to replace those horrible bolts with Stainless Allen's & Washers while you're in that area.

 

[marc11]

Thanks for the quick replies, I have the plastics off and have been looking, tracing, etc to ensure where the leak is coming from. This AM I cleaned all up with brake cleaner and fired up the bike, I can clearly see a steady stream of coolant coming from "middle" of the lower portion of the right side pump cover right in the seam where the pump cover meets the clutch cover. Not a drop from the weep hole and everything north of that looks dry as a bone. Hoses were all replaced by the PO about 40k miles ago.

 

[dduelin]

Take some pictures if you can.

If it's not coming from the tiny round weep hole forget about the water pump.

It kind of sounds like you are describing coolant is coming out of the drain channel that comes out a square hole on the right side of the engine. The clutch cover and water pump cover are right there. The drain outlet hole may be blocked. The drain channel comes down from the top of the engine behind the water pump cover and exits out the square hole where the water pump cover mates to the block above the water pump cover.

If so, focus on a coolant hose weep, seep, leak in the Vee or thermostat housing weep, seep, or leak above the engine. These are so common they rate a thread a week.

 

[marc11]

Take some pictures if you can.

If it's not coming from the tiny round weep hole forget about the water pump.

It kind of sounds like you are describing coolant is coming out of the drain channel that comes out a square hole on the right side of the engine. The clutch cover and water pump cover are right there. The drain outlet hole may be blocked. The drain channel comes down from the top of the engine behind the water pump cover and exits out the square hole where the water pump cover mates to the block above the water pump cover.

If so, focus on a coolant hose weep, seep, leak in the Vee or thermostat housing weep, seep, or leak above the engine. These are so common they rate a thread a week.

100 percent not from the weep hole, I have some pics let me get a link up; but what you are describing sounds about what I am seeing, I guess pulling the tank is next, sure glad I filled it up before pulling into the garage Sunday...pics incoming

 

[marc11]

Here are some photos: https://photos.app.goo.gl/tVyqkMBBKirTRvSm9

A little hard to get a good photo but you can see the weep hole is clean, but if you look at the gap between the bottom of the clutch cover and the pump cover there is coolant and there is where it is coming out of, and not a drip either a good slow stream of it...I am not sure the location of the square hole, been looking for it for a while, can't see to find it...then again finding the hole has been a struggle for me since high school...different issue.

 

[Andrew Shadow]

I am not sure the location of the square hole, been looking for it for a while, can't see to find it...

I can see the square hole in your second photo. Have a look at the below article, it has very good clear photos.
Your 2004 doesn't have the elbow and hose on the round drain hole. This was added in 2008.
ST1300 - Water Pump Weep Holes

 

[Ashley]

This was my bike that I sold to Marc and I feel horrible about this leak. It definitely was not leaking the last time I rode it in December and no puddles in garage. As Marc stated I replaced 9 hoses in the V of the engine at 42,000 miles in June of 2018.

 

[dduelin]

 

[dduelin]

This was my bike that I sold to Marc and I feel horrible about this leak. It definitely was not leaking the last time I rode it in December and no puddles in garage. As Marc stated I replaced 9 hoses in the V of the engine at 42,000 miles in June of 2018.

I can vouch for this. I think I rode with Ashley the last time he rode that ST. Temperature changes bring weeps, seeps, leaks as dissimilar materials expand and contract at different rates.

 

[Rob F]

I haven't been on the site for quite a while and as i opened it this morning the first thing i seen was your post.
I have been plagued with coolant leaks on this bike since i bought it a year ago. I feel for both Mark and the PO-Ashley.
When i bought my bike it was mid Feb and could only look at it in the PO's heated garage. Looked good no leaks. Trucked it home ( 4hrs one way) and stored it in my unheated Sea Can. a few weeks go by and all of a sudden there is a puddle of coolant underneath. Turns out that in cold temps the waterpump seal and some hoses shrink and voila. I road all summer with minimal leakage and then this winter here we go again. I just finished replacing the hoses i could get to without removing the intake plenum and also installed a new waterpump with all the seals. I was just coming onto the site to give all those that are doing their own pump job a warning about making sure that the pump shaft is pressed to EXACTLY the specs they give. If not, there is the possibility the impeller blades will scrape on the face of the pump cover. Also that o-ring on that cover is a real bitch to stay in place i ended up using a light coating of sticky grease to hold it in. Also you will want a nice tight fitting socket that fits snug onto those pump cover bolts. Of course the center 2 recessed ones are the tightest and my socket was slipping with a real possibility of rounding the corners on the bolt head. A real nail biter of a job and so far no leaks. The leaks have ticked me off so much that i will be selling this bike off. Anyone want a 2007 with 106,000kms with a recent waterpump job? Trade for an air cooled bike?

 

[marc11]

I can see the square hole in your second photo. Have a look at the below article, it has very good clear photos.
Your 2004 doesn't have the elbow and hose on the round drain hole. This was added in 2008.
ST1300 - Water Pump Weep Holes

Thanks I see what the square hole is now. The investigation continues but more and more perhaps it is not the pump, that would be really good news to me.

 

[marc11]

After closer checking, thanks to you all, looks like it is coming from the square hole which is somewhat of a relief. I will get to removing the tank and airbox to see if I can find what is leaking, hoping just a hose clamp came loose, but even if it is the t-stat far better than a water pump IMHO.

 

[Andrew Shadow]

Fairly common issue to have leaks from the coolant hoses attached to the thermostat and under the throttle bodies. Almost every ST1300 had some degree of leakage from these hoses from new until the hose clamps were tightened up. Honda was a little light with the torque on the clamps.

Some people have replaced the clamps with constant tension hose clamps. Others, myself included, just snugged them up and then give them a little tweak whenever they are in there. Don't go nuts and overtighten them, you could damage the hoses.

 

[marc11]

Fairly common issue to have leaks from the coolant hoses attached to the thermostat and under the throttle bodies. Almost every ST1300 had some degree of leakage from these hoses from new until the hose clamps were tightened up. Honda was a little light with the torque on the clamps.

Some people have replaced the clamps with constant tension hose clamps. Others, myself included, just snugged them up and then give them a little tweak whenever they are in there. Don't go nuts and overtighten them, you could damage the hoses.

Thanks, just waiting on a siphon pump to be delivered to drain the full fuel tank, then I will dig into it and fix it up...we have snow and ice today and just saw a salt truck go down my road so the sense of urgency has diminished a bit.

 

[billo]

I guess pulling the tank is next, sure glad I filled it up before pulling into the garage Sunday

 

[Andrew Shadow]

Thanks, just waiting on a siphon pump to be delivered to drain the full fuel tank, then I will dig into it and fix it up...we have snow and ice today and just saw a salt truck go down my road so the sense of urgency has diminished a bit.

You don't really need a siphon. If you don't want to wait for it to arrive, see the below method that will drain all but a few ounces of fuel from the lower tank.

Draining the Lower Tank
(Courtesy of John, AKA BakerBoy on ST-Owners.com)

If you want to drain both of your fuel tanks, leaving only a small amount of gas where the pump doesn't go, remove the hose labeled #6 in the below picture and QUICKLY attach a similar size hose to the exposed nipple. Lead the hose to a very big gas can!

1. Have a big gas can with you!
2. There will be hardly any gas left in either fuel tank.
3. Be quick swapping the two hoses when you first start out. You will lose a little gas, but the quicker you are the less you will lose!

The below photo shows the lower fuel tank hose connections.

There are 4 fuel connections on top of the lower fuel tank, numbered as indicated in the picture above:
1- Small hose that vents lower fuel tank vapours into the upper fuel tank.
4- Large hose that connects the upper fuel tank to the lower fuel tank.
5- Pressurized fuel delivered out of the fuel pump to the fuel rail above the throttle bodies.
6- Depressurized excess fuel returned from the fuel rail.

The image below shows the upper fuel tank hose connections.

1- Vent tube to allow air to escape the lower fuel tank during fill-up.
2- Breather tube connected the charcoal canister.
3- Drain tube to evacuate fuel spills or water from around the upper tank filler neck.
4- Large hose that connects the upper fuel tank to the lower fuel tank.
A- Electrical harness for the fuel level sensors.

 

[SMSW]

You can get to the thermostat by removing the radiator and frame brace behind it. This is easier than going down from above (which involves removing the tank air box, etc.). Most of the leaks I have heard about were from hose clamps on the big hoses - stat housing and radiator. If you do go down from above, be sure to throw your philips screw driver away and only use a JIS screw driver on the airbox screws. They can be pretty tight. A philips will cam out and damage the screws.