The snow started falling here today , so since its a Honda - I'm looking hard for things to do. The ST is new to me and I want her to be ready , when summer comes back ! I've read that there can be certain problems with leaks in the cooling system - hoses under the carburators and these aluminum Elbow joints (2) on the hoses. Are those elbow joints something that should be changed regardless of how they look -since I'm going in there to have look ? Anything else that should be changed in there - regardless ? . Might be a lot to hope for , but I was hoping to have the parts before I start - so I can finish . It's a 2000 mod , 80 000 km. very clean , I haven't found any corrosion anywhere on the bike . I've only had one day of riding around - She didn't miss a beat and don't have any reason to suspect leaks , but want to make sure things look ok . Thanks for any tips on this matter !
ST1100 cooling system maintenance ?
- Thread starter JJames
- Start date
ST1100Y
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Here is what I keep an eye on:
- overflow hose (at the connection on t/stat housing)
- radiator cap (seal suffers cracks)
- thermostat & O-ring (replace at certain age)
- corrosion of radiator fins
- radiator hoses & clamps
- fan stat (replace at certain age)
- radiator drain-plug & rubber gasket (its plastic, can crack...)
- internal passages
- 2 elbow joints & O-rings
- internal bypass hose (sitting behind t/belt housing, often overlooked, fatal when dried and brittle...)
Flush system, use silicate free coolant only...
- overflow hose (at the connection on t/stat housing)
- radiator cap (seal suffers cracks)
- thermostat & O-ring (replace at certain age)
- corrosion of radiator fins
- radiator hoses & clamps
- fan stat (replace at certain age)
- radiator drain-plug & rubber gasket (its plastic, can crack...)
- internal passages
- 2 elbow joints & O-rings
- internal bypass hose (sitting behind t/belt housing, often overlooked, fatal when dried and brittle...)
Flush system, use silicate free coolant only...
Erdoc48
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- Jan 25, 2009
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- 1,437
- Age
- 59
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- Myrtle Beach, SC/ Sometimes Colorado
- Bike
- 94/00/04 STs, FSC600
Opinions will vary...a lot. I have a 2000 as well so it is now coming up on 21 years old and parts do get old I guess. There’s 2 coolant hoses that run under the carbs as well as the main upper and lower hoses- the metal elbows under the carbs I guess can deteriorate and the O rings associated with them can leak. Being the worry wart I am, I changed all those parts about 3 years ago when I swapped out my timing belt. At the time, my ST had 33K miles on it (yours has ~ 50K miles). In truth, all the parts I swapped looked in excellent shape, including the timing belt, but being that the bike is 20+ years old, I guess fear got the best of me. The peace of mind is great so now I can plan on riding the next 20 years without an issue. If you do this work, get new carb isolators as well since they’re older now. Partzilla.com should have all the parts you need assuming they ship out of the US. For the record, I did all this work on my 94 with 35K miles at that time (late 2017) and the parts were in great shape as well. Some have indicated that the hoses under the carbs can balloon and fail leaving you stranded, but that was not noted on my ST.
As above, my overflow hose was a little old, so I removed the overflow bottle, cleaned it, and replaced the hose from the Tstat housing to the bottle with new clamps. It may also be reasonable to check your valve clearances if you’re doing regular maintenance at 50K miles- it is likely they will all be in spec, as mine were when checked.
As above, my overflow hose was a little old, so I removed the overflow bottle, cleaned it, and replaced the hose from the Tstat housing to the bottle with new clamps. It may also be reasonable to check your valve clearances if you’re doing regular maintenance at 50K miles- it is likely they will all be in spec, as mine were when checked.
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JJames
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Thanks ! A lot to check up on , I've already come to the conclusion , that I'll have to take a good look before I start ordering parts. The T-belt is also getting changed . I'll check out partzilla.com as well.
ST1100Y
Site Supporter
When already going there, I'd do spanner, idler and w/pump as well...
ReSTored
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At the 10 year mark for my 2002 I pulled the carbs and changed out all of the hoses and the elbows as well. At that time I viewed this as just regular preventative maintenance and relatively cheap insurance against a leak during a trip where I'd be stranded a 1,000 km away from home. There's nothing complicated about pulling the carbs off and changing out everything, but it is time consuming and certainly nothing you want to attempt to tackle by the side of the road somewhere. Due again in March 2022.
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JJames
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Yea , thats what I'm thinking too , now is the time for coolant leak prevention , and a pain if it happens far from home.
I guess every bike is going to be a little different regarding the condition of those hoses under the carbs, but mine blew out on me while riding, so I had to trailer the bike home. My bike is a '97 and it blew out on me in '13, so mine were 4-5 years newer than yours are now when it blew, but had about 2x the mileage FWIW. Do you have any idea if a previous owner had replaced them?
The failure mode I experienced is commonly reported here with those hoses. They swell up due to heat in their location inside the engine V, and eventually split along the length of the hose, dumping all the coolant in a matter of seconds. Not a difficult job, and the parts aren't expensive, so well worth replacing them if they're original. The one hose that didn't fail had swelled to probably close to 2x its original diameter, I was quite surprised at what I found hiding under those carbs.
replace the following:
1. both hoses
2. both elbows, and O-rings
3. carb boots
there's also a small diameter hose that goes to the t-stat housing that they only sell in a 3 meter length for some reason, even though you only need 20-30cm of it. Its 5.5mm I.D. hose, which can probably be purchased from an auto supplier rather than buying the full 3m length from Honda.
The failure mode I experienced is commonly reported here with those hoses. They swell up due to heat in their location inside the engine V, and eventually split along the length of the hose, dumping all the coolant in a matter of seconds. Not a difficult job, and the parts aren't expensive, so well worth replacing them if they're original. The one hose that didn't fail had swelled to probably close to 2x its original diameter, I was quite surprised at what I found hiding under those carbs.
replace the following:
1. both hoses
2. both elbows, and O-rings
3. carb boots
there's also a small diameter hose that goes to the t-stat housing that they only sell in a 3 meter length for some reason, even though you only need 20-30cm of it. Its 5.5mm I.D. hose, which can probably be purchased from an auto supplier rather than buying the full 3m length from Honda.
ReSTored
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The other thing I'd add to this is take lots of close up pictures when disassembling things. Also, when tighening up all of the various hose clamps make certain that they are oriented in such a manner that you can reach them and tightened them up if needed at some point down the road without getting into a major disassembly again.
AFAIK the hoses under the carbs aren't accessible without removing the carbs, so this strategy isn't going to work. You can see them by removing the gas tank and going in from the back, but I don't think its possible to get under there and do any work without removing the carbs.
However, your advice does apply regarding the clamps for the carb boots, they're designed to fit a certain way on the boots, so taking pictures before removing them is a good idea to remember how they are oriented for re-assembly.
ReSTored
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My advice pertained to all of the clamps. not just those under the carbs. That said, I had a loose under carb clamp and a minor leak about 2 days before my 3y warranty expired. Off to the dealer it went and they told me they were able to tighen up a couple of the clamps without removing the carbs, didn't ask at that time how they did it. I was skeptical, but the ST went another 7 years without leaks until I changed out the hoses & elbows in 2012. But your point is taken in that it's pretty tight in there.
Also have a 21 year old ST1100 with 75K miles on the clock. And yep all original hoses every where on my bike. Probably should think about swapping them out but if it ain't broke do you fix it? I'm planning on a coolant change this spring so I'm thinking of changing the lower radiator hose and top hose coming from the thermostat housing since it'll be easy to get too once the panels are off. I can tell you the Japanese makes some fine water coolant hoses as I still have the original ones on my 16 year 225K miles Toyota.
I don't have (and never did) an 1100, but I think there has been discussion here* about using a long, flexible screw or nut driver to get to those hose clamps, which is why they have to be positioned carefully. Did not @Igofar post a picture of his such tool? If nothing else, and you cannot reach these clamps, how do you get the carbs off in the first place? This discussion that I remember also mentioned you tighten the clamps until the spacing between the two projections of the clamp are a specified number of mm apart - NOT by torque. Overtightening these is as bad as leaving them too loose.
*This discussion I remember might have been about the clamps on the rubber hoses between the throttle bodies and the engine on a 1300.
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JJames
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I have a feeling everything looks good - under the hood - . But it seems like those 2 elbow/water joint are spooky / brittle and probably should be delt with for peace of mind. I'll have to take a good look at the rest. I'm going to try and find out how long time the parts dealer needs to get these other parts -and price .
I worked at Toyota many years , as a mechanic , and my Land Cruiser is also a 2000, there is not a crack in any hose there -so I agree about Japanese hoses. Could also be the cool climate here - dashbords never crack from the sun over here. We will see!
One thing that isn't giving me peace of mind is a T-belt i ordered. GATES T325 TIMING BELT (8595-00763). I just ordered it ebay (uk dealer) -$ 16.00 - now I see that Honda parts dealers are taking $120 . Hmmm - Is this the right belt -or whats going on ?
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JJames
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Max1chase1 has a you tube video ,where he shows how and why the clamps (heads) Have to point the right way.
yes, that's the same belt many of us have used in the past, its essentially the same as the Honda OEM belt. FWIW, nobody has ever reported removing a timing belt, at any age, that didn't look practically brand new. We all replaced them for peace of mind, but that's one part that doesn't appear to age at all on the ST1100.
The under-carb hoses are a different story, they have left many a rider stranded after their catastrophic failure, and are pretty much a guaranteed failure item if ignored long enough.
CYYJ
Michael
Hi James:
@ST1100Y gave you excellent advice in post #2 above - that's a very comprehensive list of what you should look at.
I did a similar cooling system overhaul on my ST 1300 two years ago. In the process of doing that and looking at the pictures in the Honda maintenance manual, I learned that each of the hose clamps (and each of the clamps for the carburetor isolators) has a specific orientation. The clamps will work - meaning, they will hold the hose or isolator clamped - if they are installed in any orientation - but if you want to be able to tighten a clamp up without having to tear the entire bike apart, you need to install the clamp so that the screw on the clamp is in a specific location. This will allow you to get a screwdriver or other tool into the guts of the bike and onto the clamp without having to do a complete teardown.
So, do pay very careful attention to the orientation of all the clamps when you remove them - at the same time, look at the illustrations in the maintenance manual, and visualize how you would get a screwdriver onto that clamp once everything is re-assembled. That will ensure you get everything put back together in the correct orientation.
Michael
@ST1100Y gave you excellent advice in post #2 above - that's a very comprehensive list of what you should look at.
I did a similar cooling system overhaul on my ST 1300 two years ago. In the process of doing that and looking at the pictures in the Honda maintenance manual, I learned that each of the hose clamps (and each of the clamps for the carburetor isolators) has a specific orientation. The clamps will work - meaning, they will hold the hose or isolator clamped - if they are installed in any orientation - but if you want to be able to tighten a clamp up without having to tear the entire bike apart, you need to install the clamp so that the screw on the clamp is in a specific location. This will allow you to get a screwdriver or other tool into the guts of the bike and onto the clamp without having to do a complete teardown.
So, do pay very careful attention to the orientation of all the clamps when you remove them - at the same time, look at the illustrations in the maintenance manual, and visualize how you would get a screwdriver onto that clamp once everything is re-assembled. That will ensure you get everything put back together in the correct orientation.
Michael
I would order the Honda bulk hose to replace the small hose under the carbs - it's the correct size and high quality compared to hose at your local auto parts store, and not that expensive. Even I can afford it and I'm retired and on a fixed-income. And you will have some spare hose left over.
As as far as "don't fix it if it ain't broke" goes : You may want to re-think that idea when you are several hundred or a thousand miles from home when a hose ruptures or you just have a bad leak.
Don't forget the small hose that is connected to the thermostat housing - many posts about that splitting at the housing end & leaking. Easy to repair : just cut back past the split and re-connect. It's a low pressure hose - it just runs from the housing to the coolant tank.
I like to use "smooth band" S.S. hose clamps from McMaster-Carr, too. There are other suppliers that may be cheaper
As as far as "don't fix it if it ain't broke" goes : You may want to re-think that idea when you are several hundred or a thousand miles from home when a hose ruptures or you just have a bad leak.
Don't forget the small hose that is connected to the thermostat housing - many posts about that splitting at the housing end & leaking. Easy to repair : just cut back past the split and re-connect. It's a low pressure hose - it just runs from the housing to the coolant tank.
I like to use "smooth band" S.S. hose clamps from McMaster-Carr, too. There are other suppliers that may be cheaper
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JJames
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Question, real time as they say.. 2,3, and 4 upper clamps are loose . I can't find nr 1 clamp but... is that an engine mount on the upper right hand side (Frame) ? can I take it off with out things moving ? It would give me a better view.