VIDEO -- of my Aprilia hydraulic clutch mod

[DogBunny]

I have decided to put a hydraulic clutch on the Super RustBucket. I have literally spent hours and hours -- like an entire day -- researching this. I've read every single relevant thread on this and other forums, but maybe I'm missing some information gems hidden in member's build threads. I'm open to and am soliciting any help and suggestions.

The basis for my install is information by member osteoderm in his build thread:
https://www.xs650.com/threads/good-...another-build-thread.13561/page-3#post-138656
and info provided by member ippytattoo in a few different threads, including this one:
https://www.xs650.com/threads/hydraulic-clutch-cover-mod-service.34784/
in which he used to offer an Aprilia "kit," including modification of the left case cover.
However, these threads are over 8 years old, and all of the pics are missing from osteoderm's thread, plus he's been mia for over 7 years, so I think it's time for an update.

Here is ippytattoo's hydraulic clutch in mock-up stage. Basically, the mod is pretty simple: you bolt an Aprilia slave cylinder where the worm gear used to be, you make a longer push rod, and that's pretty much it.

Today I bought the knock-off Aprilia slave cylinder in the first picture above. So, it'll be a few days before it arrives and I can begin.

Here's another ippytattoo install in mock-up stage. Note the bleeder screw which is incorporated in the banjo bolt.

Here's another Aprilia install by short-time member Opus5150. When I first looked at this, I didn't see the bleeder screw. I though the hose went directly into the cylinder with a straight hose end, instead of the 90-degree banjo bolt fitting actually used.

Which brings me to my first question: is the bleeder screw even necessary???

In mrriggs' most excellent hydraulic clutch thread:
https://xs650temp.proboards.com/thread/17567/bolt-on-hydraulic-clutch-conversion
he states:

I despise brake fluid so this was designed as a "mineral oil" system. You will hear all kinds of opinions on what fluid is best; baby oil, ATF, fork oil, power steering fluid, or even [gasp] mineral oil brake fluid. I like fork oil because it's easy to get, has good lubricating properties and seal conditioners. I'm using the thinnest stuff I could find, RedLine "Like Water".

I agree, brake fluid sucks. Which brings me to my second question:

Why not use this stuff? Without a bleeder screw? Just fill the Aprilia slave cylinder up with fluid using a syringe, then start a gravity siphon using mineral oil in the hydraulic hose, and screw the hose into the slave as the mineral oil dribbles out. No air gets in, and the dribbled out mess is just mineral oil, so easy clean up.
I know I'm kinda getting ahead of myself, but when the time comes, is there any reason this would be a bad idea?

EDIT: Just wanted to add for the record that the Aprilia slave cylinder has a 30mm bore. Thought that might be useful for mathemagicians who are trying to figure out push rod travel, or to compare to other slave cylinder options.

 

[Signal]

Dog Bunny
Q1 I have never encountered a hydraulic clutch system without a bleed screw so in my opinion they are necessary.
Q2 You are not going to have the high temperatures that brake systems have to deal with in a clutch slave cylinder. Try the mineral oil brake fluid I am sure it will work, I have read somewhere about using baby oil in a motor cycle hydraulic clutch system (not to sure I would do that though). I have always used brake fluid largely because I know it will work and there was a bottle of it on the shelf.

 

[RC4MAN]

The mineral oil should work, there's also DOT5 brake fluid which is silicone based and doesn't damage paint work

 

[JesseeS]

I've used that stuff on one of my other bikes. For the brakes, but I dripped some and didn't seem aggressive like brake fluid would be. As long as the clutch master and the dlave are compatible with mineral oil it should be fine. As far as the bleeder valve, I would do one just for ease of use. You could do it like you say but there is always a potential for a bubble to exist. With the valve atleast you can do a reverse siphon and eliminate almost any chance of bubbles. Might make maintenance easier should you have to do anything.

I also remember them saying they modified the cover. Not sure if it was just drilling or tapping but I THOUGHT some part of the cover was milled down to make the slave sit level, but it's been a while since I've read the threads

 

[DogBunny]

Q1 I have never encountered a hydraulic clutch system without a bleed screw so in my opinion they are necessary.

I bought this bleeder banjo bolt, Drag Specialties # 1742-0159, which I think looks like a big honking piece of crud. It was the cheapest one that didn't appear to be Chinese junk and that had a reasonable delivery time. You can buy one that is more svelte for twice what this one cost.
I really don't think the bleeder OR the banjo bolt is necessary, but I can see how the banjo bolt will make attaching the hose easier -- eliminating the need to "wind-up" the entire hydraulic line as it is screwed on.

By the way, here's the link to the knock-off Aprilia slave cylinder I bought:
https://www.ebay.com/itm/253213776114
Pretty reasonable at $60, but they only have blue and red left. Fortunately, the Super RustBucket is blue, so the blue one shouldn't look too garish on my bike.
In case that link goes bad, you are looking for an Aprilia slave cylinder compatible with the following models:

Caponord​	2001 - 2008​
Caponord ETV 1000​	2002 - 2007​
Falco SL1000 (requires sprocket cover to be trimmed for clearance)​	1999 - 2006​
RST1000 Futura​	2001 - 2006​
RSV1000 Mille​	1998 - 2004​
RSV 1000 R​	2002 - 2010​
RSV 1000 R Factory​	2006 - Present​
RSV 1000 R Nera (only 200 made)​	All​
Tuono 1000 R​	2003 - Present​
Tuono 1000 R Factory​	2006 - 2010​
Fits all Aprilia V-Twin 1000cc Models with External Clutch Slave Cylinder​	All​

 

[DogBunny]

https://thexscafedotcom.wordpress.com/category/m-engine/motor-clutch/

Yeah, this is a good link with great pics of hydro clutch mods that use non-Aprilia slave cylinders. Again, installation is pretty straight-forward. To quote the link:

After handling related modifications this, to me, this makes good sense. Self-adjusting. Direct. Simple.
The first ones I saw were Kawasaki GPZ slave cylinders and matching master cylinders. Easy. Cheap. Effective. Means modifying the left hand engine cover. Opening out the hole. Sanding a flat spot on the case outside. Drilling for mount screws. Making an adapter for the push rod. Install. Bleed. Check. Use. A day-no problems.

The link also shows an internally mounted slave, like mrriggs'. Forum member Bewarethemoon has been working on an internal slave in this looong thread:
https://www.xs650.com/threads/mr-riggs-hydraulic-clutch-conversion.57974/
This will be a very slick set-up, and he plans to sell them, but he's not quite there yet.

 

[DogBunny]

The mineral oil should work, there's also DOT5 brake fluid which is silicone based and doesn't damage paint work

I didn't realize it, but the Red Line "Like Water" that I quoted from mrriggs' thread above, is actually a product. If mrriggs likes it, it has to be a good option. Same price as the Finish Line mineral oil. So, I'll use one or the other.

 

[DogBunny]

I also remember them saying they modified the cover. Not sure if it was just drilling or tapping but I THOUGHT some part of the cover was milled down to make the slave sit level, but it's been a while since I've read the threads

Dark pic, but this is what ippytattoo was offering in his "kit." Some people grind a flat spot on the cover, but he wasn't. Ippytattoo was tapping threads in the cover.

Others put a plate on the back side, and drill and tap it (non-Aprilia slave in pic). As ippy pointed out, this makes taking the installed slave cylinder more cumbersome to take off and put on. And you have to level the backside cover gussets. Ippy though there was enough meat in the cover for threads, and then he used stainless steel Helicoils for the threads for added strength, which is a good idea.

 

[gggGary]

I like the patented gggGary brake bleed technique; slave piston inserted just enough so the rubber seal is engaged. Fill slave cylinder with fluid through port, install line. NOW with port pointed up push in piston til fluid shows in reservoir, top off reservoir, done. You can pump out piston, squeeze back in an extra time or two if needed. But usually once n done.
I'd use the brake fluid that you have in the front brake cuz well, one bottle no guessing for service.

 

[DogBunny]

I like the patented gggGary brake bleed technique; slave piston inserted just enough so the rubber seal is engaged. Fill slave cylinder with fluid through port, install line. NOW with port pointed up push in piston til fluid shows in reservoir, top off reservoir, done. You can pump out piston, squeeze back in an extra time or two if needed. But usually once n done.
I'd use the brake fluid that you have in the front brake cuz well, one bottle no guessing for service.

Yeah, that's a great technique. I have my own patented technique, but yours is way better, so now yours is mine.
As for clutch fluid, I'll quote mrriggs again: I despise brake fluid...
And to quote me: I agree, brake fluid sucks.
I'm probably going to use mineral oil.

 

[DogBunny]

Here's a good pic of the Aprilia slave posted by member XsJosh in this thread:
https://www.xs650.com/threads/hydraulic-clutch-slave-diameter.57262/
Nice job, but as I wrote earlier, those big banjo-bleeders are an eyesore...

 

[gggGary]

Just got this Venhill in for the XJ1100 (this one's a double)
looks as good as the pic. Tighten the fitting with a hex found inside the bleeder bore.

the single version.

https://www.ebay.com/itm/121366460036

 

[650Skull]

I haven t tried then but looking at some of the honda slave cylinders they might work. The thing is to make sure one of the mounting brackets on the cylinder isn't going to hit the Stater part of the side case. I like the look of the Honda ones as they sit flatter and with the banjo bolt and bleed screw in different places it looks more compact...........Prices vary and cheep ones can be found.............just like all things the right question can be the difference between a good cheep part or a cheep part being cheep for a reason.

https://www.ebay.com/itm/275177852450?hash=item4011e0ce22:g:W9IAAOSwpWNiE~yL
https://www.ebay.com/itm/2015-HONDA...-/152221983638?_trksid=p2067104.m45210.l46742
https://www.ebay.com/itm/94-95-Hond...440928?hash=item48ab1cdd60:g:R3gAAOSwD4lazicd
https://www.ebay.com/itm/124348784475?hash=item1cf3c3df5b:g:WvcAAOSwwgRfar5y

 

[DogBunny]

Just got this Venhill in for the XJ1100 (this one's a double)
looks as good as the pic. Tighten the fitting with a hex found inside the bleeder bore.
View attachment 215150
the single version.
View attachment 215151
https://www.ebay.com/itm/121366460036

That is a BEAUTIFUL banjo-bleeder. I'd be all over it if I hadn't already ordered the Drag Specialties one. The Drag Specialties one is going on the Super RustBucket, so its ugliness is practically a feature.
BTW, I was about to give you a hard time for showing me a bolt with 3/8 x 24 UNF threading, but thought I better check first. Sure enough, a 3/8 x 24 UNF banjo bolt will fit in a M10 x 1.0 threaded hole, which is what the Aprilia slave has. Read all about it here:
https://www.mfcp.com/our-blog/bid/76568/Thread-Identification-for-Brake-Lines
Quoting from the article:
The 3/8” x 24NF will screw into M10 x 1 thread but not the other way around
Who'd a thunk it. You learn something new every day.

 

[gggGary]

That is a BEAUTIFUL banjo-bleeder. I'd be all over it if I hadn't already ordered the Drag Specialties one. The Drag Specialties one is going on the Super RustBucket, so its ugliness is practically a feature.
BTW, I was about to give you a hard time for showing me a bolt with 3/8 x 24 UNF threading, but thought I better check first. Sure enough, a 3/8 x 24 UNF banjo bolt will fit in a M10 x 1.0 threaded hole, which is what the Aprilia slave has. Read all about it here:
https://www.mfcp.com/our-blog/bid/76568/Thread-Identification-for-Brake-Lines
Quoting from the article:
The 3/8” x 24NF will screw into M10 x 1 thread but not the other way around
Who'd a thunk it. You learn something new every day.

My bad. The double I got is 10x 1.00
they have 10 x 1.00
10x 1.25
and 3/8 x 24NF
all in both chrome and black chrome.
Here's the one you'd want. https://www.venhillusa.com/10x1mm-domed-single-bleed-bolt-chrome-310100dc.html

 

[gggGary]

F-d myself with the fine thread, Yamaha doesn't use fine thread on the banjos. of course I had the brake lines off (the working OK, convoluted, linked XJ11 brake) BEFORE I found THAT little oopsie. Now back to square one, non functioning brake, and waiting for banjo #2 to arrive. Will report when one that FITS, is installed.

 

[DogBunny]

F-d myself with the fine thread, Yamaha doesn't use fine thread on the banjos. of course I had the brake lines off (the working OK linked XJ11 brake) BEFORE I found THAT little oopsie. Now back to square one, non functioning brake, and waiting for banjo #2 to arrive. Will report when one that FITS is installed.

I feel your pain.

My Drag Specialties banjo-bleeder came yesterday. It's not bad-looking, it's just that it's HUGE (and it didn't come with a rubber cap).

Unfortunately, I can't find the banjo bolt fittings that I use for my DIY hydraulic hoses, which SUCKS, and is going to drive me CRAZY and ruin my entire day until I find them, which I fear will NEVER happen...

Anyways, been doing a lot of work on the clutch mod project, will post something interesting soon...

 

[DogBunny]

I have zero confidence that I am ever going to find my banjo bolt fitting, so I just bought 16 on AliExpress. Four each of 4 different bends. About $4.35 each to my door, which is an unbeatable price -- this will be my third purchase of these fitting s on Ali, which is the only place to buy them if you've got the time. ETA is four weeks.
At least I found my hose -- also purchased on Ali.

 

[gggGary]

View attachment 215505View attachment 215506
I have zero confidence that I am ever going to find my banjo bolt fitting, so I just bought 16 on AliExpress. Four each of 4 different bends. About $4.35 each to my door, which is an unbeatable price -- this will be my third purchase of these fitting s on Ali, which is the only place to buy them if you've got the time. ETA is four weeks.
At least I found my hose -- also purchased on Ali.

A DIY how to make hose when the fittings arrive? ;^)

 

[DogBunny]

A DIY how to make hose when the fittings arrive? ;^)

You know, I thought I already made a thread on this, but I guess I didn't.
An excellent how-to on how to install the fittings is here:
https://www.beringer-aero.pl/wp-con...ns-for-hose-and-banjo-fittings-2014-01-31.pdf
If you glance at that link it might seem complicated, but once you actually do it, it's easy.

One thing the Beringer link above omits is how to cut your hose. Side cutters are the wrong way. Tightly wrapping where the cut will be made with electrical tape, and using a cut-off wheel is the right way. Go to the 5-minute mark of the following video:

I put some good info, pics and links in this thread, post # 82:
https://www.xs650.com/threads/1973-super-rustbucket-resurrection.58711/page-5#post-699492