Couple Of Clutch Questions (With Photos) - Help Needed Today :-)

[sawtooth]

Just ordered the following:

Slave o-ring: MT280432047

Slave cup seal: MT280332049

Can I use red rubber grease when installing these, or do I need something else?

[sting32]

I defer to JSE on that, since you are talking about inside the clutch's hydraulics, I would just dip in the brake fluid, roll onto where they go. should be lube enough?

[sawtooth]

Cool thanks

[sting32]

Thanks, do I need to drain the fluid?

hope you thought about the gasket for the cover?

the bike need to be laid on its side, when you take off and or replace the clutch side cover. I cant see how the fluid would NOT come out, you when you pull that top-hat off. at least some. Easiest way to refil, if you have help is the push fluid into nipple on clutch slave, until it fill tank on bars, problem is small little hole in tank and will cover the ceiling in fluid when you push into empty tank, so I lay a clean tank cover over the tank, maybe put tiny amount into empty tank before you start pushing up from slave, ya know. gets 99.998 of the air out that way.

Be sure to watch for falling parts, you know bearing and washer/race on clutch, thin shim on start shaft. they have a tendency, to hang onto the cover just for mere seconds due to oil film, then fall when you are NOT looking!

Edited September 10, 2013 by sting32

[sawtooth]

Thanks, what is use to push the fluid into the slave, syringe?

[sting32]

Thanks, what is use to push the fluid into the slave, syringe?

that is what I use, mine actually is one from some brake parts company, cant see the brand anymore... that I have had forever, it is a big one, pushed same hose we use for fuel line onto the tip, tied with ziptie. then push onto nipple, once you open the nipple IT SHOULD press in fairly easy, as in wont pop hose off, if you are popping hose off, your lever is adjusted wrong, probably.

USE CLEAR LINE (see through, I mean) so you can make sure you dont push bubbles into the lines.

Edited September 10, 2013 by sting32

[sawtooth]

Cool, do I have to undo the nipple or anything or should it open as I start to inject fluid?

[jse]

hope you thought about the gasket for the cover?

the bike need to be laid on its side, when you take off and or replace the clutch side cover. I cant see how the fluid would NOT come out, you when you pull that top-hat off. at least some. Easiest way to refil, if you have help is the push fluid into nipple on clutch slave, until it fill tank on bars, problem is small little hole in tank and will cover the ceiling in fluid when you push into empty tank, so I lay a clean tank cover over the tank, maybe put tiny amount into empty tank before you start pushing up from slave, ya know. gets 99.998 of the air out that way.

Be sure to watch for falling parts, you know bearing and washer/race on clutch, thin shim on start shaft. they have a tendency, to hang onto the cover just for mere seconds due to oil film, then fall when you are NOT looking!

I like to fill the top hat with fluid before installing on the post. This way you avoid the air pocket at the back of the servo cylinder problem. Be sure to fill the reservoir only about 1/2 way full, it does not vent the same way as the reservoirs on the bars.

Clean fluid is a good lube, as Sting says. You can also use a very light coating of Silicone grease (VERY light, you should only see gloss, not chunks). If you wanted a smoother clutch, you could change to DOT-5 (Silicone), which, unlike DOT-3/4/5.1, is slightly compressable. DOT-5 is compatable with all the seals.

Jon

[sawtooth]

The cover has been on and off about 10 times over the last couple days and the gasket is still sealing! Once I have the clutch how I want it i'll stick a new gasket on.

So have I got this right, after removing the clutch cover:

1. Pull the top hat off, remove reservoir cap on master cylinder, drain the oil.

2. Replace the o-ring and cup seal.

3. Fill top hat with brake fluid.

4. Replace top hat.

5. Replace clutch cover.

6. Attach syringe to nipple on clutch cover (How am i attaching hose to nipple, just push on, clamp?) (do i have to loosen nipple?), slowly feed fluid into the system until i see it in the reservoir on the master.

7. Remove syringe.

8. Pump lever a few times until no more air bubbles seep through small holes in reservoir.

9. Replace reservoir cap.

10. Go ride?

On a side note, in changing to Dot5 from Dot4, do I have to replace anything else other than the fluid itself?

Edited September 10, 2013 by sawtooth

[sting32]

I like everything you said. except lay bike on its side in there somewhere, LOL.

if you get the right size hose, I just push it on over the nipples, no clamps needed with reasonable tight fit hose. FYI I use the same thing, used for front rear brakes and clutch, nipples can a little, vary in size.

If you have to push so hard on the syringe, that the hose blows off, then something is not right, IMHO usually means your levers aren't letting the plungers in the master cylinder get back to fully "at rest", remember levers need like .5 mm of slack at least... or dirt at the of the plunger opening, that is covered by that little rubber cone shaped boot, behind the circlip that holds the "piston" in.

!11 is go ride, 10 would be make sure you clean up anywhere the brake fluid dribbled on, in my expereince if left to "dry" eats paint. or used to.

3 4 & 5 are similiar enough as far as I know, I think it was mineral oil that used to eat the seals on tophat, that you "shouldn't" be able to get anymore? AKA updated.

I do my darnedest to not mix, but even in a pinch (aka temporary) I have had to use 5 in a normally full of 3 or 4, now everything on my bike is 5. less crap to have in your toolkit.

Edited September 10, 2013 by sting32

[sawtooth]

Awesome thanks, will get on and do that then.

[tltel]

Just like to add, yes you do need to undo nipple and if you are going to drain all fluid you may as well remove the nipple and check that the small hole is not blocked with dirt before you inject it in to your clutch.

Once you have cleaned it, replace it, gently tighten, then undo about half a turn to enable fluid to be pushed into system. when its full tighten nipple up.

TLTEL

[jse]

3 4 & 5 are similiar enough as far as I know, I think it was mineral oil that used to eat the seals on tophat, that you "shouldn't" be able to get anymore? AKA updated.

I do my darnedest to not mix, but even in a pinch (aka temporary) I have had to use 5 in a normally full of 3 or 4, now everything on my bike is 5. less crap to have in your toolkit.

Mitch,

3, 4 and 5.1 are essentially the same (5.1 is a lighter viscosity, common to European high-speed ABS systems) but they are very different from DOT-5, which is a Silicone based fluid. The DOT-5 is common to military vehicle brake systems due to it being much less hygroscopic (an ability to attract and retain atmospheric moisture, yes, spelled with a "g") so storage is less of a problem and it lacks the strong solvent properties of the 3/4/5.1 type. It does, however, make the brakes feel "spongy" due to it's minimal compressability, so you will probably never see it used in racing brake systems.

You can use mineral oil in a clutch system but should never use it in brake systems due to it's low boiling temp. Mineral oil, DOT-3/4/5.1 and DOT-5 are not compatable so they should not be mixed unless you want gundge in the system or desire to replace the mineral oil seals/o-rings that have been damaged by the solvent properties of DOT-3/4/5.1.

Jon

An exerpt from one of my answers to a question a rider sent me:

It’s hard to imagine a subject duller than brake fluid, but it’s something we have contact with just about every day, directly or indirectly. Most of the time we could care less about it, but in Trials, it’s a very important material and just about all Trials bikes have three separate systems that employ brake fluid to transfer motion that make us both go and stop. Hopefully, the result of that going and stopping is dependent on years of hard earned Trials experience and razor-sharp athletic prowess, rather than an immovable object such as a tree, which is usually what happens in my case.

I like to change brake fluid about every six months when possible. It has an effect on how the controls “feel” and fresh fluid will prevent corrosion caused by water buildup in the calipers and cylinders. The polyglycol based brake fluid (DOT 3, 4 and 5.1, as opposed to the Silicone based fluid which is DOT 5) is what is called a “humectant” in Chemistry, meaning that it promotes the acquisition and retention of water. Glycol is an alcohol derivative and alcohol is the main component of gasoline additives that are designed to drive water from the fuel systems of automobiles. Polyglycol and Silicone are used in brake systems rather than another fluid, such as water, because it stays relatively consistent in viscosity from cold to hot, has a very high boiling point and provides good lubricating qualities for the various parts.

Water will get into your brake and clutch systems in a variety of ways, usually from a brake fluid container that has been opened for a while, or past the venting diaphragm under the master cylinder cap. It will collect in the lowest part of the system, usually the caliper assembly, where it will corrode the alloy components and rapidly degrade braking ability. Flushing it out when you change fluid is the only way to remove it. I like to slightly overfill the master cylinder reservoir when replacing the cap so as to minimize the amount of air (and water vapor) under the separation bladder the cap rests on. The water absorption problem is so important that some manufacturers of high level racing fluids recommend that the brake systems of racecars be bled before each racing event, particularly in wet or humid conditions.

Another of the big differences between the glycol-based DOT-3, DOT-4 and DOT-5.1 fluids is the wet and dry boiling point. The “wet” boiling point is tested with a 3% water addition to volume. DOT-5.1 brake fluid was designed to be used in European automotive high-speed ABS systems. It has the lowest viscosity of the glycol-based fluids.

DOT-5 is a different kind of animal altogether, and has a Silicone (Silicum-based Polymer) rather than a glycol (Polyalkylene Glycol Ether) base. One of the nice things about it is that it doesn’t eat the paint off your bike like the glycol-based stuff does. I like to use it in my clutch because it tends to smooth out the action and I like the “feel”. If you wanted a “quicker” action to the clutch, you might want to use the DOT 5.1 type due to its lower viscosity. The Silicone-based fluid doesn’t “absorb” water like the glycol-based types. The water will separate out as globules and can still cause problems if not flushed out on a regular basis.

Although it would seem that all the fluids should be able to be mixed, especially the DOT 5 ratings, such is not the case. DOT 3, 4 and 5.1 (amber or clear in color) can be mixed, but DOT 5 should never be added to anything other than itself. It is a chemically different compound, being Silicone based, and will give a cloudy mixture that looks like Jell-O when added to the glycol based fluids. Silicone DOT 5 is a purple color (by DOT rules) so it won’t be confused with the other types. Some racing brake fluid can only be mixed with itself and won’t mix with any other brand, such as AP600 (designed for the carbon-carbon brake systems of F-1 cars). If you feel rich, you can get some Castrol SRF brake fluid, but it will set you back over $80 a liter, a little less than a quart.

Buy fluid in small containers that will be used quicker. Never reuse fluid that has been drained and keep the caps tight on the containers to prevent moisture contamination. Remember, it’s a LOT cheaper to flush brake fluid a couple times a year than buy new components.

[sawtooth]

Done the seals this morning. To fill and bleed the system I used a 'Gunson Eezibleed' (£19.99 in Halfords), made a cap to fit the master cylinder reservoir out of aluminium and a piece of innertube, connected it to my front tyre, blasted the oil through with the pressure from the tyre (20psi for this) until all that was coming out of the bleed nipple was clean oil (no air). All seems to work fine now but time will tell if changing the top hat seals will stop my oil from disappearing! It works great on brakes too!

Cap and fill bottle...

Cap...

Drain from bleed nipple...

Edited September 14, 2013 by sawtooth