Clutch slave cylinder replacement

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Fire-medic

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This is a job many people dread. When the slave cylinder leaks, there's no way to get around it. You have to fix it. I suggest replacement with a new one. Yes rebuild kits are available, but if it doesn't work (the rebuild) for you, do you want to repeat the job? I didn't think so.

For this and all work, wear PPE (personal protective equipment).

Order your parts before you take things apart. Buy a new slave cylinder, a left side engine final drive cover gasket, and you might consider buying the gasket on the pushrod in the engine case. Some people anneal the copper washers that seal things, you can do that by just heating them with a propane torch, and letting them cool. I usually don't bother. You could also replace them, they're cheap. I just inspect mine, and clean and re-use them. If I'm suspicious, I replace it. You should be able to get generic ones from your local auto parts store, just be aware of the 'fatty' (thick) ones. Get slim ones.

I bought a Handi-lift pneumatic lift, and I cannot describe how much easier it is to work on the bike w/one.

Here we go.

Remove the left footpeg.
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Remove the shifter assembly, which includes two allen head machine screws for the left side engine final drive cover. Pry off the linkage and set the assembly aside.
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Remove the other allen screws for the left side engine final drive cover. The one at 6 o'clock has a flat copper washer, it needs to be there to seal the cover because it's below the oil level of that part of the engine. Remove the cover by gripping it top & bottom, it should come off easily. Don't expect to re-use the OEM gasket. It will tear removing the cover, and maybe a couple ounces of oil will come out, so have a pan underneath the engine.
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Bend up the tang on the bracket holding the clutch rigid line in place, so when you remove the banjo bolt from the clutch slave cylinder hex bolt extension, you can remove the hose to the right.
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I suggest using an impact driver to remove the slave cylinder machine screws. You can probably do it with just a ratchet wrench, but if you bugger the allen recess, you're gonna be an unhappy guy, trying to get those screws out.

I used my 3/8" drive impact driver, and a allen key socket, with about a 6" 3/8" extension, w/a 24 oz. ball pein hammer. Be careful to insure the allen key is firmly and fully inserted into the screw head. Make sure the impact driver is already turned 'lefty-loosie' before you deliver the blows. Probably the first good blow will break it loose. Loosen one (12 o'clock) and the other (6 o'clock), then back them fully out.

There is a steel bracket that the wires run through, you will see it when you remove the cover. You need to pry that open, and to remove the wires there, stretch them down outside of either of the halves of the steel bracket and below the engine side where you removed the side cover. This will allow you room to remove the slave cylinder.
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Be sure that when you remove the slave cylinder screws,you don't lose them. They are the same length.

You'll discover after a bit of fiddling how you need to turn the slave cylinder to remove it. Think of one of those wire puzzles you worked as a kid where you had to get the pieces exactly aligned, and then the thing came apart.

Take a look at the backside of the slave cylinder. Does it look as bad as mine? All that crystallized brake fluid, nasty stuff. And corrosive. You will re-use the elongated hex nut that the clutch hose attaches to. Be sure to keep track of the copper washers on either side of the hose fitting, and the banjo bolt.
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Remove the hex elongated nut, thoroughly clean it. I use carb cleaner aerosol and plenty of paper towels. A blast of compressed air should remove any residual crud. If you have hardened deposits, use a small screwdriver, be careful not to scrape/gouge any mating surfaces.

Now open that nice new slave cylinder from its package. Slip on the copper washer over the male threads of the elongated brass hex nut. Attach the washer/nut to the new slave cylinder, in the middle of the piston housing.

Now attack the engine where the slave cylinder was. Use a flashlight and see all the crud in the area of the leaking slave cylinder. You need to remove all that. What I did was take 2 or 3 paper towels, fold them over on themselves to make a layered pad, and then I folded it over the tip of a long pry bar. You could use a long handled screwdriver, but you want a long one, if you don't have one, get one. I used some baling wire around the wad of paper towels a couple inches below the blunt end of the pry bar, and a pair of linesman's pliers go around the pry bar and folded towels, to hold the towels tight to the end of the pry bar. You make a swab to access insid the narrow confines of the area where the slave cylinder resides. Spray the &%^#$!! out of the area with your carb cleaner using the red wand extension, and then attack the area with your paper towel swab/pry bar or long screwdriver. Make sure that you go all around the area. View the area with your handlight/flashlight to ensure your thoroughness. All deposits have to be removed. More carb cleaner, as required. When the paper towel wad got dirty, I removed the baling wire, reversed the folded paper towels, and reattached the baling wire, to get a clean surface to finish the job. Your 'before' and 'after' pics should resemble mine.
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Now replace the slave cylinder. You should be able to introduce it into the space from the side, not from below, and twist it to insert it into the cavity. Then position it for mounting. The bleed nipple is at 12 o'clock. When you have it positioned correctly, use your 6" ratchet wrench extension and your allen socket to start the top screw, do NOT run it down tight! Then do the 6 o'clock screw. Snug each down.

Now I recommend you use the impact driver to tighten the screws, you don't and shouldn't need to 'WHACK' it, just a couple light taps so that you feel it draw down tight. If you want, you can dig out the factory manual and see what the torque spec is, probably a low double-digit number.

OK, you are done with the hard part, congratulations! I chose to bleed the line before re-installing the left final drive engine cover. But first, you have to reattach the banjo fitting to the slave cylinder extended brass nut, after having everything really-cleaned. So make sure that you remove the banjo, don't lose the copper washers, clean it all, and reassemble. Snug the banjo bolt down good, you may find that the elongated brass nut turns a bit as the banjo bolt torques-down. That's OK, you just need to be sure all the fittings are tight, so they won't loosen in service.

Remove the master cylinder reservoir cap. I like to use my impact driver and a brand-new #1 phillips tip I use only for this job. Hopefully your M-whatever-size metric machine screw isn't phillips-buggered, and it comes out. I've had to use a dremel tool to cut a slot across a buggered phillips, to make a tight fit with a good blade screwdriver, to remove them. I hope you don't.

Use your syringe to suction dry the master cylinder. Use paper towels to remove any crud you find. Add a bit of brake fluid if needed to get the last bit of debris in-suspension, in the brake fluid, so you cal blot it up with your paper towels. Now you should have a clean, dry master cylinder reservoir.

We are assuming your master cylinder is functional, it doesn't need a rebuild. That's another how-to.

Now, draw some fresh brake fluid (Never Re-use Brake Fluid!) into your syringe with a 1/4" I.D. clear plastic hose, about 4" long, and make sure that your slave cylinder bleeder screw is open. From snug, but not tightened-down, you should be able to do the reverse-bleed only opening the bleeder about one-half turn.

Be sure you have a basin under the engine, because this is gonna spill a bit of brake fluid.

Place your syringe into the open, removed bleeder nipple hole, and add enough fluid to fill the slave cylinder. Now, replace the bleeder nipple when you see the fluid is to the top of the brake bleeder threaded hole. Hand-tighten it until it is snug-closed, but not tightened. Now back it open about one-half turn as I previously mentioned.

If you have a 60 or 100 cc/ml syringe, 'fill 'er up!' Bleed the excess air out so the brake fluid is almost to the top of the 1/4" tubing when you hold the syringe upright, with the tubing pointed straight-up. Now comes the messy part.

Place the 1/4" tubing of the syringe over the bleeder nipple, and press-down. The plastic hose should be fully-inserted onto the bleeder nipple. Now use two fingers to squeeze the tubing together, so you're pinching the clear plastic hose onto the bleeder nipple from the sides. This will minimize the fluid that leaks. If you don't pinch the hose, you will waste a lot of fluid. It will take longer, and you won't be able to do the reverse-bleed quickly or easily.

Remember that your master cylinder reservoir is dry. Slowly, carefully, push the syringe plunger, and watch the master cylinder reservior. You may need to do a couple or three re-fills of the syringe, depending on how much fluid you start with in the syringe, how well you squeeze the plastic hose from the sides to get a seal on the bleeder nipple, and the amount of leakage.

When you are empty with the syringe, quickly remove the clear plastic hose from the bleeder nipple, and use your fingers to snug-down the brake bleeder nipple while you re-fill the syringe. Be sure to open the bleeder nipple that half-turn before you re-attach the filled syringe. Be sure to slide the plastic hose onto the bleeder nipple as-far as it will go. Be sure to squeeze with two fingers the clear plastic 1/4" hose sideways onto the bleeder nipple.

Again, inject the brake fluid using the syringe. Pretty-soon you should see the dry master cylinder reservoir 'pee' fluid and air bubbles from the tiny hole in the floor of the reservoir, the one closest to the banjo bolt. As you push the syringe plunger, more fluid will accumulate in the reservoir. Be careful! Too-much pressure using the syringe when the hydraulic line is filled will cause the fluid to erupt in an 'Old Faithful' geyser of corrosive fluid from the master cylinder reservoir hole!

Sometimes there is a bit of particulate material in the 'empty' hydraulic line that is disloged as you reverse-flush the system. If you get a partial accumulation of fluid in the master cylinder reservoir, and then the syringe plunger encounters resistance, and you cannot push the plunger with the same ease as-before, STOP! You have probably flushed some line debris which is now obstructing the master cylinder hole, where the fluid had been entering the master cylinder reservoir. Send davesax an email, and ask him what guitar string is the correct size one to stick in that tiny hole. Or, jus use a needle or a pin, something small enough to pass-through the master cylinder small hole without damaging the metal.

BE CAREFUL! Clearing the obstruction from that hole will probably result in a spray of fluid that will travel several feel away from the bike! Your debris now has allowed a build-up of pressure, that you released by the needle or pin probe. PPE (personal protective equipment) such as eyewear is mandatory for this procedure, from beginning the work.

You should be able to resume the reverse-bleed once the pressure is relieved. At some point, instead of seeing a string of bubbles erupting from the reservoir hole, with brake fluid, you will notice a little 'loop' of fluid rising above the surface of the brake fluid in the reservoir. When you get no bubbles, and only the solid 'loop' of fluid coming-out of the reservoir hole, you're done with the syringe.

Remove the syringe, and quickly finger-tighten the slave cylinder bleeder nipple. Now use a 5/16" socket or wrench to snug it down.

Take a look at the fluid in the reservoir, add enough fluid to put fluid about 3/16" from the closest point the fluid comes to the top lip of the reservoir. Looking at the sight glass, you should be at about the halfway point. You can re-install the reservoir cap, I use my impact driver and that brand-new #1 phillips tip. No I do not use the impact driver and a hammer to secure the cap. I just use the fat bodyof the impact driver to get a better grip on the screw being snugged-down.

Now attack the clutch handle. Fanning it rapidly should quickly result in you getting resistance against the diaphragm spring in the clutch basket. For me, after 'fanning' the clutch lever a few times, the lever travels maybe an inch at the ball-end, before I get resistance, and then the same resistance for the lever going to the grip. That should be it. Doing the reverse-bleed, doing it thoroughly, and having no issues with the parts that make up the system, contributing to a leak, like an internally-bleeding master cylinder plunger, or one that leaks brake fluid down the handle to the ball on the end of the clutch lever, means you need a new master cylinder. I don't rebuild them, I replace them. Yes a rebuild kit is about 1/4 the price of a new master cylinder, but if I can get an OEM part for something like this, I'm buying it.

You still have to attach the final drive engine side cover. Thoroughly clean all the gasket material you can using a new single-edged razor blade. Be careful not to gouge the metal. Again, I use the carb cleaner aerosol can and paper towels. I use a piece of 240 grit sandpaper to remove any dried-caked gasket material. Give everything a good cleaning on both the engine in the bike, where the gasket is going to sit, and the side cover, using the same technique.

Open that neat Yamaha OEM gasket bag, remove the gasket, and be sure that the two hollow dowels are still in the outer cover. Before you install the cover, you have to bundle all those electrical lines and place them inside the steel keeper bracket which is behind the side cover you're about to install. Make sure you get all the wires into there, and use a pair of pliers to squeeze closed the bracket, being careful not to pinch the wires.

Place the final drive cover with its gasket into place. Ensure the gasket didn't slip out of position. Replace the allen machine screws, I start at the 12 o'clock position and go clockwise. Remember that the one at 6 o'clock has a narrow flat washer, as it's open to the oil of the final drive, and that flat washer needs to be there, or you will have a big drip! I run-in all the screws but the shifter screws, snug, not tight. Then I install the shifter bracket and ensure that the height of the shifter will be OK for my operation. Then attach the small clamp onto the shift shaft, and tighten the 10 mm hex bolt. Now tighten the screws in a cross-pattern, like a car wheel.

Replace the footpeg bracket. Two screws that could use a bit of blue locktite are these.

Now I use the carb cleaner aerosol can to spray down the area where I worked, to ensure that I remove all the brake fluid. More paper towels.

And, give that clutch lever a squeeze or two, and revel in the fine job you just did, replacing that bad slave cylinder. :clapping::punk::eusa_dance::cheers:

Of course, test the bike for proper operation of what you just repaired, before putting it back onto the road.

If your clutch line is OK, and you installed a new slave cylinder, and you quickly got a firm lever, you shouldn't have to tie-down overnight the lever. Your reverse-flush moved all the air bubbles up to the master cylinder, and out of the sealed system. But if it works for you, OK. I think it keeps the pink elephants away, too, as I havent seen any around after trying the lever tie-down overnight. :rofl_200:

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More pics
 

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Still more pics.
 

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And more.
 

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The last set.

I took all these shots in the vertical camera position, but they 'flopped.' Sorry.

If a moderator wants to correct that, and maybe insert the pics wherever they belong in the narrative, I'm sure anyone trying to follow this would appreciate it, me-too.

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Great write up FM. Simple directions. Thanks for posting.

Sent from my SM-G930R4 using Tapatalk
 
I've done them before & assumed we all can benefit from clear, simple instructions. This is a daunting task for many. With proper tools & a good place to work, it's easier. You avoid the 'gumption traps' that make the job hard. Taking pics along the way, working by myself, it was under 2 hours. "Your results may vary."

And the lever quickly developed clutch pressure, after using the syringe "reverse bleed." I didn't try tying down the lever overnight, and this morning, I still had great clutch pressure.
 
Definitely a great job!! The syringe technique seems to be a perfect way to do this.


Sent from my iPhone using Tapatalk
 
Buster has a great site, we all should be doing what we can by financially kicking in a contribution from time to time, and of course, things like tech write-ups, parts for sale at non-ebay prices, and just contributing to a healthy forum of knowledge and VMax experience.

I wish I had better results with the pics, but it was all I could do just to get them uploaded. The article would read better with the pics in the proper orientation, in-sequence with the narrative, but it takes me too-long to do that with my system, if one of the moderators perhaps would spend the time to fix the pics, it would help "the Hive." Then we can be busy-bees getting our clutches working just-so, or whatever other things the tech info helps us to be able to do, without having to take it to the shop.
 
For the several times I have done this, having an instructional walk through solidifies the steps in my mind. It felt as I was doing it for the first time in the past and just plodded my way theough it. Pics were great and useful too Phil. You do not get a write up like that in a factory manual. And what is up with those crappy factory manal pictures anyways ?! Thank you.
 
I don't use a photo-hosting storage site, or I would've been able to insert the pics to fit the narrative. Also, sometimes the pics are upright in my folder but when they post-up, they rotate. Not-sure about that. Some websites have the ability to drop the pics into the text, but anytime I've tried to use the URL method, no-go. I think that's where the businesses offering picture-hosting is used.

One thing that I like about the write-up is the reverse-bleed method description. It's just the quickest way to bleed brakes and the clutch, and to flush your complete system. It can be a bit messy, but the results are achieved quickly, it solves several bleeding issues at-once, and it works. My home-made tool is from supermarket supplies (a 'meat flavor injector' syringe), a Schrader valve from the auto parts store (the threaded, screw-on kind, remove and throw-away the valve core) and a short length of 1/4" plastic tubing. Once you see how-easy it is to get quick results on your brakes and the hydraulic clutch, you'll never do it the old-way.
 
Fire-Medic: Thank You
Pretty easy repair and solves the disappearing clutch fluid mystery! LOL
It will be the last one I do on mine as it's time to let it go. Crash back in 2020, on my Indian ,has me in a place where the Max just isn't the right machine for me any longer.
Awesome Machine it has been though and super grateful to all the contributors on this site over the years.
God Bless
 
Hey FM, is the clutch slave cylinder also called a Push Lever Comp.? This is how it is listed on Partzilla, I think. See attachment. If so, do I need anything besides what is shown as #28? There are assorted bits like #'s 24, 25, 26 (oil seal, o-ring, push rod guide). Should I get new ones of these? Any help you can provide would be greatly appreciated. BTW, great write up and pictures! I'm afraid if I order from Partzilla they're going to jack me around like they are with my oil filter cover bolt. I ordered it on 5/15/22 and they keep pushing back the ship date.

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