Coolant Flush at Dealer

[kajmaya]

I have a 2010 ST1300 with 11,018 miles. I took it into the dealers for a coolant Flush along with some other Minor Maintance work. The dealer made this note on the invoice: "Coolant was coming out of breather hose prior to coolant flush. May continue. Keep an eye on it for now, may require repair". I'm wondering what is the breather hose and where is it located? Do I need to be concerned?

 

[Gus1300]

I would ask them to point it out to you so you know what hose they saw it coming from. Is it possible it's not a 'breather' but the overflow?

 

[Larry Fine]

Shoulda asked when you were there.

Bet you know that now.

 

[TerryS]

Hard to believe that a dealer would return the bike in that condition. The only breather is at the coolant reservoir, and the only reason for coolant to ever flow from there is if the tank is chronically overfilled so that when the hot liquid expands into it, it overflows. Or if the radiator cap is faulty preventing pressurising of the cooling system and allowing steam to blow into the reservoir and push fluid out the breather. Neither is health, especially the latter, but neither are the difficult to correct, a new OEM cap is $20 at Partzilla.

 

[Al Gully]

I'm thinking its a 2010 and there is a drain hose now attached to the water pump mechanical seal drain.
Thinking he used that term breather instead of drain hose.

 

[Igofar]

I have a 2010 ST1300 with 11,018 miles. I took it into the dealers for a coolant Flush along with some other Minor Maintance work. The dealer made this note on the invoice: "Coolant was coming out of breather hose prior to coolant flush. May continue. Keep an eye on it for now, may require repair". I'm wondering what is the breather hose and where is it located? Do I need to be concerned?

IIRC the Honda service manual indicates that the Mechanical seal inspection for '03-'07 indicates: if there is leakage, the mechanical seal is defective and you need to replace the water pump as an assembley... However, on the same page....Mechanical seal inspection (After 07) "a small amount of "weeping" from the bleed hose is normal.
Rumor has it, that so many water pumps were replaced under warranty, by mistaking leaking coolant clamps, as failing water pumps, that they changed the wording after 07 indicating that it was normal to have the end of the hose damp, and seeping a little bit.....However, Some service managers, or shops, were told to instruct their staff to "indicate" stuff like that on the repair order, as a scare tactic to get the customer to worry about it and bring the bike back in at a later date for further service work (that may not have been needed) as a way of making $$$$ for the shop.
This is just a "Rumor"

 

[Al Gully]

I also heard those pretty lil service center advisors make a pretty penny on commission telling you need both transmissions replaced

 

[CYYJ]

I think that the service adviser probably meant one of the two weep holes on the front right side of the engine when they said "breather hose". Most likely the "round hole". Here's a link to a post that shows the two weep holes and gives an explanation of what they are for and what the significance of coolant coming out of them is: ST1300 - Water Pump Weep Holes.

The ST motorcycles don't have a "breather hose" component on them. The later production ST 1300s (including your model year) do have a drain hose attached to the "round hole". It's not a breather... the drain hose just routes any leakage down to the ground beneath your bike, rather than letting the leakage run down the side of the engine.

The only other possible source that the service adviser might have been referring to would be the overflow hose on the coolant reservoir tank (located on the left side of the motorcycle, directly ahead of your ankle when you are sitting on the bike), but I think that is unlikely.



Michael

 

[Gus1300]

Just looked at the Weep Holes article from Dec 2018. It says that if coolant comes from the round hole (behind the water pump) that the pump likely needs replacement. Is there a seal or something that normally keeps coolant from exiting that location? Does anyone have a pointer to what it looks like BEHIND the water pump, or what the back of one looks like? That might be good to add to the article, as an identification of what 'normal' and 'failed' look like.

Thanks for the great pictures and explanation of the locations!

 

[SupraSabre]

I think that the service adviser probably meant one of the two weep holes on the front right side of the engine when they said "breather hose". Most likely the "round hole". Here's a link to a post that shows the two weep holes and gives an explanation of what they are for and what the significance of coolant coming out of them is: ST1300 - Water Pump Weep Holes.

The ST motorcycles don't have a "breather hose" component on them. The later production ST 1300s (including your model year) do have a drain hose attached to the "round hole". It's not a breather... the drain hose just routes any leakage down to the ground beneath your bike, rather than letting the leakage run down the side of the engine.

The only other possible source that the service adviser might have been referring to would be the overflow hose on the coolant reservoir tank (located on the left side of the motorcycle, directly ahead of your ankle when you are sitting on the bike), but I think that is unlikely.



Michael

On the 2008 and after, the "weep hole" was replaced with a "weep tube". This was so the shops wouldn't get the waterpump leaking, mixed up with the hoses in the valley leaking out the square hole and replacing the waterpump when it didn't need it.

So, when the waterpump starts leaking, it will be under the engine, from the "weep tube".

 

[Igofar]

Thanks Bob, in addition to that, the service manual now indicates that on the 07 and later, a small amount of weeping (damp end of hose) is to be considered normal.
So if yours is just collecting coolant at the end of the hose (under the front of the cowling) wipe it off, and run the engine to verify is it pulsing out like a tear drop every second or so, or is it only collecting a small amount of dampness at the end (which is normal).

 

[SupraSabre]

If you all need a demonstration on a waterpump leak, I'll take a video of my '04#1. I leaks quite well, has been for four years.

Someday I'll even get around to replacing the waterpump!

 

[CYYJ]

Does anyone have a pointer to what it looks like BEHIND the water pump, or what the back of one looks like?

Hello Gus:

Below are two pictures. The first one shows what the water pump of a 2012 ST 1300 looks like when viewed from the front, after the cover over the water pump has been removed.

The second picture shows what the water pump looks like from the rear, after the big cover on the front of the engine (the part that the water pump cover attaches to) has been removed.

Because this motorcycle is post-2007, there is a small curved tube embedded in the 'round hole'. The tube is clearly visible in both photos. Honda installs a hose on this small tube to direct the leakage onto the ground. The hose was removed for cleaning before I took these pictures.

During normal operation of the fully-assembled motorcycle, the front side of the water pump is surrounded by engine coolant, and the rear side of the water pump is exposed to engine oil spray to lubricate the bearings you see in the picture.

Michael

Front of Water Pump


Rear of Water Pump

 

[Igofar]

If you all need a demonstration on a waterpump leak, I'll take a video of my '04#1. I leaks quite well, has been for four years.

Someday I'll even get around to replacing the waterpump!

Please do, I'd like to save it for my "this is what a leak really looks like file"
If you don't want to post it here, just email it to me.

 

[Gus1300]

Thanks Michael,

I think I answered my own question by referencing the service manual. It appears on the oil side there is an oil seal behind the bearing that meets up with a mechanical seal behind the oil seal. From the coolant side there would just be the mechanical seal behind the impeller. That's what I was wondering if anyone had a picture of, how the mechanical seal (coolant side) could fail and allow liquid to exit. It all makes better sense now.

I hope mine stays as dry as it has for a long, long time...based on the tools and press required to replace the seals, I'm not sure this is something I could dig into on my own!

 

[SupraSabre]

Please do, I'd like to save it for my "this is what a leak really looks like file"
If you don't want to post it here, just email it to me.

I'll try to get it this weekend.