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Offline Fernie 66

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No Hydraulic Clutch Pressure
« on: 28 November, 2019, 12:44:33 AM »
Hello from Toronto Canada.

Can anyone give me a hint as to what the problem might be with with my bike.  I have a 2009 Biffer, with 60,000 Kilometres on the clock.  The bike is simply great, however for the past three years when I take it out of storage at springtime, the clutch has absolutely no pressure.  No leak found, and mechanics cannot diagnose the problem.  So we simply bleed the clutch, add new fluid, and carry on.  The bike will behave flawlessly for the rest of the season. 

Just a thought, . . during the winter, I store the bike in an unheated garage, with temperatures sometimes well below zero Celsius.  Could the cold cause the seal on the clutch reservoir to shrink, and allow air  in ?? 
The brake hydraulics are not affected at all.

Many thanks, any help will be much appreciated. 


Offline Art

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Re: No Hydraulic Clutch Pressure
« Reply #1 on: 28 November, 2019, 12:47:30 PM »
Condensation is the worst enemy of hydraulic fluid and in a Canadian winter I'd guess you experience more condensation  than we do here in the UK. I'd suspect moisture ingress by way of condensation since the clutch fluid will absorb water like a sponge. Did your mechanics test the old fluid for water content?



Online iNCORRIGIBLE

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Re: No Hydraulic Clutch Pressure
« Reply #2 on: 28 November, 2019, 01:44:22 PM »
Would the brake hydraulics not also be similarly affected for the same reasons? Time expired seals in the clutch hydraulic circuit seems a possibility.Ed. p.s. did see a discussion once that an increased frequency of hydraulic fluid changes actually hardens the seal material rendering it less efficient.Sounds unlikely but i do not know what Lockheed,Pirelli.Brembo, Girling etc .would be prepared to admit to.Ed.
« Last Edit: 28 November, 2019, 01:53:18 PM by iNCORRIGIBLE »

Offline Fernie 66

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Re: No Hydraulic Clutch Pressure
« Reply #3 on: 28 November, 2019, 10:57:41 PM »
Thank you both for your response.

Re the brake hydraulics, - - -  luckily they've been problem free, but good point though. 

Re the clutch hydraulics, my  local shop did acknowledge possibility of moisture entering the system, and/or weakened seals.    But as they are extremely busy in the spring pulling out customers bikes from their winter storage, I think they're just happy to bleed/recharge the system, and send me on my way.  The  bike then performs well during the summer, so I foolishly hope the problem has solved itself;  silly I know.  This has now happened twice in a row. Apparently, its cheaper to bleed the system than to replace the seals. 

For this winter, they've recommended I keep the clutch lever depressed for the entire storage period, possibly until next April ?? The hope is that the constant pressure exerted on the clutch system might keep the seals expanded and in place,  while keeping moisture at bay.  Does this sound right ?? Wouldn't the  pressure eventually weaken and dissipate by the  time April arrives ??

Thanks again; Don.




Offline Fernie 66

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Re: No Hydraulic Clutch Pressure
« Reply #4 on: 29 November, 2019, 12:11:26 AM »

PS:

Can I do anything to prevent the condensation, other than throwing a heated blanket over the bike (joking).  The garage is really a glorified shed, cold, and damp.  I, addition to the storage preparation, I usually cover it with a cotton bedsheet .


Online moayling

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Re: No Hydraulic Clutch Pressure
« Reply #5 on: 29 November, 2019, 12:33:05 AM »
I run a small greenhouse type heater that looks like a tube. Costs almost nothing to run but keeps the moisture at bay

Offline Art

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Re: No Hydraulic Clutch Pressure
« Reply #6 on: 29 November, 2019, 02:51:01 AM »
If its cold and damp...

Offline Bifferman 2

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Re: No Hydraulic Clutch Pressure
« Reply #7 on: 29 November, 2019, 04:06:51 PM »
Hi Fernie 66

It seems to me that your mechanic/shops idea of holding the clutch lever in for the whole of your winter might NOT be such a good idea as you will continuously be exerting pressure on the clutch springs :156: :084   It will also put permanent pressure on the large return spring in the slave cylinder (engine end) which can't be doing it any good either.  The master cylinder on the handlebar also has a weaker return spring in it and that would be under continuous compression as well :155: .

It rather sounds as if you do actually have a hydraulic fluid leak and, in the absence of an obvious leak my guess would be that it is in the oil rings within the slave cylinder.  I don't know for sure but I suspect that any small fluid seepage would be retained within the slave cylinder cover and/or possibly drain out via the lifter rod which runs from the slave cylinder LHS of engine, through the engine to the clutch itself, from there I am guessing BUT it will only take a VERY small amount of fluid loss to cause your symptoms.  Not having had to strip down my master cylinder I can not be sure but I would have thought that yoy would see a small leak around that area of the handlebar if there was one.  Out of interest, you say that the fluid was 'topped up' before bleeding, do you know just how much the flupd had dropped in the resevoir? 

If you are happy with topping up the clutch fluid and bleeding the system, which is a simple job, then fine I suppose :155: but clearly there is an underlying reason for the lack of hydraulic compression.  Would you leave this alone if it was an issue with the brakes at the end of Winter ?  and just a thought, when was your brake fluid completely bled and replaced ?  Have you downloaded the MK1 Workshop Manual - chapter 10 is where to go for matters clutch.

I am a bit out of touch with the Biffer having sold mine two years ago but even though I can't recall this issue having raised it's head previously it may be worth doing a thorough search of the clutch and transmission section on the forum.  The search facility is only so so and quite often it will not throw up a similar issue but you can use Google to search the forum with greater success.  Richardcbf is the top man for searching on here using Google and I am sure that he wrote aa how to do it on one of the threads so you could search for that as well.

Regards
Bifferman 2 (AKA Bifferman)
 :149:




« Last Edit: 29 November, 2019, 04:07:36 PM by Bifferman 2 »

Offline Shed

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Re: No Hydraulic Clutch Pressure
« Reply #8 on: 30 November, 2019, 08:14:43 AM »
*Originally Posted by Fernie 66 [+]
they've recommended I keep the clutch lever depressed for the entire storage period, possibly until next April ??

 :027:  :151:  :157: What? 
In my (humble) opinion, any workshop suggesting such woeful advice is a clueless one, so ditch it and use another.
In fact, makes me think, when they have refilled it, have they actually put DOT4 fluid in there?!

Given that, in simple terms, you only have the clutch fluid reservoir with brake fluid & a few parts inside it, a clutch hose pipe with brake fluid in it, and down at the engine end the bleed nipple on the slave cylinder, and the slave cylinder piston O rings, and that's pretty much it. Not many suspects really. Strip all the parts and inspect/replace as necessary. Maybe even treat yourself to a reservoir kit & a new diaphragm and new DOT4 fluid. Is the hose itself and bleed nipple ok too? Even these two bits aren't much to replace if need be.

4-28 & 4-29 https://bob.ollis-brown.co.uk/manuals/cbf1000/2006-2008-CBF1000-A-4%20MAINTENANCE.pdf

and, https://bob.ollis-brown.co.uk/manuals/cbf1000/2006-2008-CBF1000-A-10%20CLUTCH-STARTER%20CLUTCH.pdf

Not a specific recommendation, just examples:

https://www.ebay.ca/itm/Clutch-Master-Cylinder-Repair-Kit-fits-Honda-CBF-1000-2006-2010/141833583267?hash=item2105f0baa3:m:mHyUCYPAg20gBCbHzEKIedQ&vxp=mtr

https://www.ebay.ca/itm/Tourmax-Brake-Reservoir-Diaphragm-Seal-Set-RVD-101-Honda-CBF1000-2006-2010/401723806470?hash=item5d889ad306:g:rmwAAOSwqT9cgUW9&vxp=mtr
« Last Edit: 30 November, 2019, 08:43:24 AM by Shed »

Offline Fernie 66

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Re: No Hydraulic Clutch Pressure
« Reply #9 on: 03 December, 2019, 12:29:01 AM »
Hello all:

Thanks to everyone for your insight/recommendations.  I'll definitely give it a rethink, and possibly look for another shop.  Though I confess, I share part of the blame for this continued problem.  As already mentioned, the loss of pressure happened at each spring for the past two years.  Since the bike subsequently performed well after each quick fix, I did not follow it up with the mechanics ; I had hopes the clutch problem had gone away.  Depending on what happens this coming spring,  I'll obviously act on your recommendations. 

Many thanks again.  And just so you know, I am extremely envious of you who can still ride your bikes this winter, (depending where you're located in Europe), and of course, how you can easily hop into neighbouring countries.  This past summer I did a 5,000 kilometers round trip from Toronto  to Nova Scotia, and only managed to go through 3 provinces !!!!  And. . . . . .,  were presently buried in snow;  guess I'll get the skis tuned.

Don.