Losing clutch hydraulic fluid

[L.Lind]

Hi. I'm new to this group. Ride is a 2006 st1300. I do my own maintenance. Recently started losing clutch fluid. The hydraulic line is dry. The bolt at the clutch cylinder is dry. If I squeeze clutch lever and wait, a small amount of fluid appears on the side and bottom of the transmission housing. I think I can see a tiny hole in the transmission housing, directly below where the clutch cylinder is. Could this be where the fluid is coming from? Does it mean a diaphragm in the clutch is bad? What advice can you folks give? Thanks, L. Lind

 

[Igofar]

What year and what model bike?
Sounds like your clutch slave cylinder has given up the ghost.
Provide the year and model, and I'll look up the part numbers for you.

 

[CYYJ]

I think I can see a tiny hole in the transmission housing, directly below where the clutch cylinder is. Could this be where the fluid is coming from?

The tiny hole at the bottom is there by design, to let hydraulic fluid out if a leak develops in the slave cylinder for the clutch system.

Because you have stated that you see fluid leaking out there, it's about 99% probable that you have had a failure of the clutch slave cylinder. That is a part that you can replace yourself, provided you are a contortionist.

I had to replace that part last year on my ST 1100 (it's much easier to replace on a ST 1100 than a 1300) - here's a link to a post that will give you an idea of the concepts (and a few of the pitfalls) involved in replacement and then re-filling and bleeding the system: ST1100 - Replacing the Clutch Slave Cylinder.

Regrettably, the task is more difficult to carry out on a ST 1300 because the slave cylinder is more difficult to access - it's not at the front of the engine. Some forum members have successfully carried out a replacement. Here is an article by @MaxPete about ST 1300 clutch slave cylinder replacement: ST1300 - Clutch Slave Cylinder Replacement. That article and the 7 pages of discussion and additional information that follow is really scholarly - by the time you read it all, you'll know everything you need to know to do the job.

My guess is that the parts cost will run you somewhere between $100 and $200 - but that is just a guess, based on my recent experience with my ST 1100.

Michael

 

[L.Lind]

What year and what model bike?
Sounds like your clutch slave cylinder has given up the ghost.
Provide the year and model, and I'll look up the part numbers for you.

The bike is 2006, st1300 Honda

 

[Bush]

Michael

Probably of no help to you but thought you should know that there is a commercial flight leaving Morocco sometime this weekend for Canada, just in case there was some way for you to get there.

 

[L.Lind]

The tiny hole at the bottom is there by design, to let hydraulic fluid out if a leak develops in the slave cylinder for the clutch system.

Because you have stated that you see fluid leaking out there, it's about 99% probable that you have had a failure of the clutch slave cylinder. That is a part that you can replace yourself, provided you are a contortionist.

I had to replace that part last year on my ST 1100 (it's much easier to replace on a ST 1100 than a 1300) - here's a link to a post that will give you an idea of the concepts (and a few of the pitfalls) involved in replacement and then re-filling and bleeding the system: ST1100 - Replacing the Clutch Slave Cylinder.

Regrettably, the task is more difficult to carry out on a ST 1300 because the slave cylinder is more difficult to access - it's not at the front of the engine. Some forum members have successfully carried out a replacement. Here is an article by @MaxPete about ST 1300 clutch slave cylinder replacement: ST1300 - Clutch Slave Cylinder Replacement. That article and the 7 pages of discussion and additional information that follow is really scholarly - by the time you read it all, you'll know everything you need to know to do the job.

My guess is that the parts cost will run you somewhere between $100 and $200 - but that is just a guess, based on my recent experience with my ST 1100.

Michael

Thanks! This is very helpful. I plan to remove the old slave cylinder before ordering another.
L.Lind

 

[Bikeric]

Welcome to the forum from Cornwall UK!

 

[MaxPete]

Hi LLind: yes, that small hole un the underside of,the clutch slave cylinder (CSC for brevity) is called a weep hole and it is supposed to be there and if fluid is coming out, then it is doing precisely what it is supposed to do: keep a failed CSC from pumping clutch fluid (really it is brake fluid) into the engine.

A couple key points:

• DO NOT plug that weep hole - it might keep your clutch working for a short while, but doing so could cause major damage to the engine;
• DO NOT get any of the clutch / brake fluid on anything you care about - like painted surfaces or in your eyes. Brake fluid will dissolve paint in seconds and what it could do to eyes does not bear thinking about.
  

Michael (CYYJ) has noted that some of the photos in the article I wrote on replacing the CSC on the ST1300 have gone astray. I will go and see if I can fix that issue.

EDIT - OK the original article has been fixed with better figures and some corrections.

Cheers,

Pete

 

[SMSW]

• (Can’t figure out how to turnoff these GD point list bullets.

And I was wondering how you managed to format your reply with bullets. I thought it was v. good!

 

[MaxPete]

And I was wondering how you managed to format your reply with bullets. I thought it was v. good!

hehehe - I do love my iPad, but it is pretty crummy for editing these posts I'm afraid.

Anyhow - the article has now been fixed with better figures and even some typos corrected.

Cheers,

Pete

PS: LLind - welcome to the Forum from Canada's sunny southern coast in Windsor, Ontario!

 

[CYYJ]

I plan to remove the old slave cylinder before ordering another.

Uh, based on my past experience, I'm not so sure that's a good idea. I recommend that you order ALL the parts and tools that you will need - the replacement slave cylinder, gasket(s), hydraulic fluid, crush washers, any special tools you will need, etc. before you begin the disassembly process.

I say this because it is a messy, not-a-lot-of-fun job, and it requires a lot of disassembly. Half-way through the job, you'll have a lot of little parts & fasteners removed, hoses dangling, etc. If you then have to take a break of 3 to 5 days (best-case scenario for parts delivery), parts will get misplaced, you'll forget what order things came apart, and so forth.

Get everything you need together, clean out a big area of the garage to do the work in, install fresh batteries into all your worklights, and then dive in and get it all over with in one day.

Been there, done that.

Michael

 

[SMSW]

Take pictures as you go. Lots of pictures.

 

[ST-Traveler]

Sounds like your clutch slave cylinder has given up the ghost.

Hey everyone,
Have you any idea what causes this?

 

[MaxPete]

Hey everyone,
Have you any idea what causes this?

Really, I’d say it is simply that little clutch slave cylinder (CSC) piston reciprocating in and out through the seal and as noted earlier and in the article, the whole engine-side of the slave cylinder is open the atmosphere through the weep-hole. That means any road gunk, salt, sand and moisture will get up in there and cause corrosion on the inside bore of the CSC - and that will eventually chew up the seal and cause it to leak.

As several people have noted, the majority of ST1300s are now from 10-15 years old (i.e. 2005-2010 models) and there seems to have been quite a spate of these failures since I did mine in the fall-winter of 2016-17 - my bike is a 2007.

All of the failed slave cylinders I have seen come out the same - the seal has failed totally and the inside of the bore is fairly badly messed up. That’s why I don’t recommend trying to rebuild them - a brand new unit is $75 and a rebuild kit is about $60. It simply is not worth saving $15-20 and risking having to do the whole danged job again given what a PITA it is to get in there.

....just my $0.02 CDN (which is worth around 0.014 USD at present and dropping).

Pete

 

[L.Lind]

Really, I’d say it is simply that little clutch slave cylinder (CSC) piston reciprocating in and out through the seal and as noted earlier and in the article, the whole engine-side of the slave cylinder is open the atmosphere through the weep-hole. That means any road gunk, salt, sand and moisture will get up in there and cause corrosion on the inside bore of the CSC - and that will eventually chew up the seal and cause it to leak.

As several people have noted, the majority of ST1300s are now from 10-15 years old (i.e. 2005-2010 models) and there seems to have been quite a spate of these failures since I did mine in the fall-winter of 2016-17 - my bike is a 2007.

All of the failed slave cylinders I have seen come out the same - the seal has failed totally and the inside of the bore is fairly badly messed up. That’s why I don’t recommend trying to rebuild them - a brand new unit is $75 and a rebuild kit is about $60. It simply is not worth saving $15-20 and risking having to do the whole danged job again given what a PITA it is to get in there.

....just my $0.02 CDN (which is worth around 0.014 USD at present and dropping).

Pete

Pete, thanks for the article and pictures. I'm well on the way to a new clutch piston. Got it ordered. You in southern Ontario? I did a Friday 13th ride in to Port Dover a couple years ago. Have friends in Hamilton and Waterloo.
Thanks again,
L.Lind

 

[MaxPete]

Pete, thanks for the article and pictures. I'm well on the way to a new clutch piston. Got it ordered. You in southern Ontario? I did a Friday 13th ride in to Port Dover a couple years ago. Have friends in Hamilton and Waterloo.
Thanks again,
L.Lind

Hi LLind: yes, I live in Windsor, ON - about 6 miles south of the Ambassador Bridge which joins WIndsor and Detroit MI.

Lemme know if you need any further advice or instructions.