Clutch Line Replacement - 2004 R1100S

[aj.bauer]

Great forum: I've benefited from the information shared here many times for my bikes, but have not been able to find a direct answer to whether one can get relatively direct access to the hydraulic clutch line attach location on the slave cylinder (in front of the rear shock, beneath the air box).

I replaced the brake lines on the bike with stainless steel versions for preventive reasons, and had hoped to do the same with the clutch line. Not sure if removing the muffler would give enough access, or if one does need to remove the air box to access the banjo bolt (air box removal is bit involved as I understand it). Maybe I could get a tool in to loosen / tighten the bolt without removing anything else, but doubt I would be able to even get the bolt to start threading to reattach.

For reference, I have been reading this thread http://advwisdom.hogranch.com/Wisdom/Clutch Flush.php.html

Any thoughts out there?

 

[PAS]

I would also post this on the bmwsporttouring.com forum (oilheads) It has been discussed in the past.

 

[roger 04 rt]

More important than replacing the clutch lines is inspecting/replacing the clutch slave cylinder which can leak and contaminate your clutch. All can be replaced by removing the rear wheel only.

 

[gsaddict]

The clutch slave line does not need to be replaced like the rubber brake lines do, it is synthetic.
What should be done is the mod below so the lower fitting does not rust out and leak.

Also, lubing the little bearing on the end of the slave piston every 40-50k miles will greatly extend its life.
As the picture shows below, they come very sparsely lubed from the factory.
Any HT wheel bearing grease is acceptable.

Another good mod to do is to drill a hole in the bottom of the transmission case so in the event of a fluid leak, it will drain out instead of migrating along the pushrod and contaminating the clutch. The hole can also be monitored as for any potential future leakage.

A final flush with fresh DOT 4 and you will be set.

 

[aj.bauer]

Thanks for your thoughts everyone. I found by simply removing the rear wheel and the rear shock that there is plenty of access to remove the clutch line banjo fitting at the slave cylinder.

I did notice, since there wasn't enough room for a proper torque wrench, the Spiegler banjo fitting is ~3mm thicker than the OEM fitting (~50% thicker), but the Spiegler kit does not come with a longer banjo bolt (OEM is 17mm long). This probably would not have been a problem had I not over-torqued the OEM banjo bolt, but I did and rendered a poor seal for the couple threads that were engaged. So I went looking for a longer banjo bolt, and could not find one, even from bicycle shops. I made / machined one from a basic 20mm long, 6mmx1.0 stainless hex bolt, and now all is good.

 

[lowndes]

AJ,

Several comments on the slave cyl hydraulic lines. I finished replacing mine during a clutch replacement back in Jan this year on my '99 R1100S. The slave cyl leaked, soaked the clutch plate requiring the clutch replacement. I replaced the brake lines AND the clutch line with a complete set from Spiegler ($200 on Amazon)

The banjo fittings ARE a different size from the brakes, AN2 maybe. Different bolts, fittings and seals.

DOT4 decomposes OEM brake lines AND hydraulic clutch lines. Maybe brake lines decompose faster because of the pressures. Try some DOT4 on your paint. Same thing, just faster.

The hyd lines bolt to the slave cyl. The slave cyl can be easily removed from the tranny by three bolts on the back of it. Pull the slave cyl out and attach the hyd lines then reinstall it. Replace the slave cyl piston seal (BBY has a kit, BB21522335061RKZ, $35) while its out to help prevent problems.

I posted a bunch of pics at http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=980709&page=1 Pages 1 and 3.

Roger 04 recommends drilling a drain hole in the tranny case at the slave cyl. Now, Roger 04 is a LOT smarter AND much, much more experienced in BMW mechanics than yours truly, but i do humbly submit that the drain hole should be drilled much closer to the other end of the slave cyl recepticle in the tranny. See my pics. There is an approx 1/4" space or gap between the slave cyl piston and the tranny. The drain hole needs to be into that gap. Where Roger 04 shows the hole is almost completely blocked by the slave cyl itself. There isn't much clearance between the slave cyl and the wall. It is possible to drill either hole with the tranny still on the bike. I explain how in that referenced forum post. I'd drill it with the slave cyl out (while replacing the slave cyl completely or just the seal) but it could be drilled with it in with some careful measurements.

The banjo fitting for the short bleed-fitting-hose needs to be angled to the REAR, not the front per the OEM fitting in Roger 04's pic, to clear the air filter box. The small "stop" on top of the slave cyl (also see Roger 04's pics above) will prevent this REAR angle. The stop can be easily removed with a pair of dikes, just snip it off. That allows you to zip tie the bleed fitting to the rear passenger foot peg bracket with much more room to access the fitting for bleeding the system, too.

Believe me, drilling that little hole IS MUCH, MUCH EASIER THAN A CLUTCH JOB!!

Lowndes

Edit: Relocated Clutch Bleed line and fitting pics:

 

[gsaddict]

AJ,





Roger 04 recommends drilling a drain hole in the tranny case at the slave cyl. Now, Roger 04 is a LOT smarter AND much, much more experienced in BMW mechanics than yours truly, but i do humbly submit that the drain hole should be drilled much closer to the other end of the slave cyl recepticle in the tranny. See my pics. There is an approx 1/4" space or gap between the slave cyl piston and the tranny. The drain hole needs to be into that gap. Where Roger 04 shows the hole is almost completely blocked by the slave cyl itself. There isn't much clearance between the slave cyl and the wall. It is possible to drill either hole with the tranny still on the bike. I explain how in that referenced forum post. I'd drill it with the slave cyl out (while replacing the slave cyl completely or just the seal) but it could be drilled with it in with some careful measurements.

The banjo fitting for the short bleed-fitting-hose needs to be angled to the REAR, not the front per the OEM fitting in Roger 04's pic, to clear the air filter box. The small "stop" on top of the slave cyl (also see Roger 04's pics above) will prevent this REAR angle. The stop can be easily removed with a pair of dikes, just snip it off. That allows you to zip tie the bleed fitting to the rear passenger foot peg bracket with much more room to access the fitting for bleeding the system, too.

Believe me, drilling that little hole IS MUCH, MUCH EASIER THAN A CLUTCH JOB!!

Lowndes

You are quoting my post, allow me to respond.

You can chose drill the hole further in but there is sufficient clearance for any Gear Oil or DOT 4 to seep out if the need arises. I prefer to position the hole there as it will slow water ingress during a water crossing.

Regardless of position we agree the hole is a smart modification!

 

[PGlaves]

You are quoting my post, allow me to respond.

You can chose drill the hole further in but there is sufficient clearance for any Gear Oil or DOT 4 to seep out if the need arises. I prefer to position the hole there as it will slow water ingress during a water crossing.

Regardless of position we agree the hole is a smart modification!

I agree there is plenty of clearance between the recess and the cylinder body that where the hole is fore-to-aft makes little difference. In fact, you can accomplish the same thing as a drilled hole by filing or grinding a notch in the aft edge of the case where the flange on the slave meets the case. BTDT I used a Dremel tool.

See the 5th or 6th photo in post #4. Notch as close to the bottom missing the area with the bolt hole.

 

[gsaddict]

I agree there is plenty of clearance between the recess and the cylinder body that where the hole is fore-to-aft makes little difference. In fact, you can accomplish the same thing as a drilled hole by filing or grinding a notch in the aft edge of the case where the flange on the slave meets the case. BTDT I used a Dremel tool.

See the 5th or 6th photo in post #4. Notch as close to the bottom missing the area with the bolt hole.

Yep, that works too!

 

[aj.bauer]

I believe I owe thanks to those who were advocating I replace the slave cylinder or at least drill a weep hole. I have a new slave on the way Tuesday, but pulled the old one this morning. When I pulled it there was old fluid pooled in the bottom of the slave cylinder receptacle (image included) so I assume my slave is a bit leaky. My clutch was not slipping when I last rode the bike (November - I'm in Minnesota), so maybe I caught this before it became incredibly painful.

My weep hole (1/16-inch = 1.5mm diameter) is drilled per the Lowndes location, but realize a hole further aft on the transmission housing will accomplish the goal too without getting too close to the smaller ID step at the front end of the slave receptacle.

I drew up a little schematic with my rough measurements to help while locating the hole - though I doubt the measurements would pass a gage study given the circumstance.

 

[lowndes]

Hey, AJ,

That looks very familiar. When that fluid builds up between the slave cyl and tranny and gets the up to the clutch rod (that's it sticking out the rear of the input shaft in your pic) it will travel down that hollow shaft and dump on the chutch plate. My OEM clutch never slipped or gave me any indication anything was wrong. The only symptom was a lot of "oil" coming out of the clutch housing, both sides and the bottom. Since the clutch seemed to be OK, I thought it was a RMS that was leaking. Slave cyl is still easier than the two RMS's.

Your clutch rod will slip out and then back in, no problem. Some trannys have a felt belt around the rod to keep it from rattling in the shaft. Some Jap bikes have an O-ring as an oil seal to prevent this problem. The R1100S tranny has neither.







Lowndes