Slave Cylinder Drilling Procedure

[kevincook]

I recently drilled a weep hole for my clutch slave cylinder and wrote up these instructions to document the procedure. If anyone finds anything wrong or has suggestions please let me know. I hope someone finds this useful.

The first time it took approximately 3.5 hours to do this, but that included taking notes and pictures. The next three that I was involved with each took 2 hours or less.

Good Luck,
Kevin

[JATownsend]

Kevin,

Really Great Work!

I can't add or make any cogent suggestions as I have not yet done the procedure, but, with your help I will probably attempt it soon!

Thanks! :D :D :D

[early1]

Seriously, thanks for the effort.
Very nice.
I did mine when I replaced the clutch and had the tranny loose.
I drilled a little more vertically , due to the advantage of having the transmission out.

[grahamw]

Clear, consice with excellent pictures - thank you very much - just a pity it is a couple of months to late and you stopped before you got the gear box out ;-)))

'or has suggestions please let me know'

Page 2 - put the caliper bolts back in their respective holes once the caliper is removed.

Page 4 - Needle bearings - if they seperate and fall out should they not be replaced? I replaced mine but maybe I did not need to.

Page 6 - remove circlip (9) should read remove circlips (1&9)?


Can you tell that I am in work and bored rigid?

Once again many thanks

[hoodoodrum]

Kevin, your procedures are the most readable and understandable directions for a mechanical procedure I have ever read through. Great job and thanks for your efforts here.


BTW.... I had my rear tire changed out today at the dealer. The BMW certified mechanic said he is now drilling slave weep holes in his clutch work on LT's. Says it's not "endorsed" by BMW, but during update training, the mechanics talk among themselves and regularly suggest the procedure to each other. Says it SAVES many clutches that are in still very good condition.

[ajs]

kevincook,
Just the best and easily understood procedure I have ever read in all my 64 yrs. I have been thinking of doing this procedure as well but was reluctant to get started for fear of a shortage of a critical tool or of lack of confidence to do the job correctly. NOT ANY MORE. Thanks for the great confidence booster.

I do have a few questions that I could use your and other knowlegable LT owners thoughts on.
1. Is the casting that is drilled Aluminum?
2. Is it critical how far into the housing from the gasket face the hole is drilled?
3. Would it be just as effective or even advisable to notch it at the 6 o'clock position on the gasket face of the clutch cylinder housing rather than drill it? I'm thinking if the purpose for the gasket is negated by the drilling then notching might work as well.

Thanks again for the great job
Austin S

[dshealey]

--------1. Is the casting that is drilled Aluminum?Yes2. Is it critical how far into the housing from the gasket face the hole is drilled?The goal is to get it as far forward as you can, but not to damage the transmission seal. If you drill straight up, with the drill as far forward as it will go in the recess under the cylinder mounting boss, it will miss the seal.
3. Would it be just as effective or even advisable to notch it at the 6 o'clock position on the gasket face of the clutch cylinder housing rather than drill it? I'm thinking if the purpose for the gasket is negated by the drilling then notching might work as well.I thought of doing that when I did the job, but the nose of the slave cylinder has some taper to it, so there is more clearance at the front than thre is at the rear, so the fluid will have a little more resistance to gravity drain near the seal. Don't know if it is enough resistance to make it not work well though.

[jackd]

Kevin Great job.. Looks great. :thumb:

Doesn't look as intimidating as the last time I saw them.

Few suggestions...

Can you post or include a template for the modified socket in the instructions? I know you were going to cut a bigger window for the hex key. When I replace my slave I will need to make or get that socket made.Haven't figured that out yet.

It would also be nice to know much you modified (cut off) the hex key you use with that modified socket.

Because most of the LTs at our tech session had corrosion on the back input pressure hose line (P/N 21522333450 $65) it might be good to mention that it might need to be replaced if someone is doing the slave replacement at the same time as drilling.. Great touch putting the part numbers for the slave and gasket in the instructions.

You did not mention how to pull out the rod to inspect if you already have fluid in the housing. I know it is not part of the drilling procedure but I would expect that most higher mileage 'drillers' will find some fluid and the probably would want to clean the rod and replace the felt pad (P/N 23211230440 $3.40), if equipped, on the actuation rod. Procedure was simple enough and you had to know to grip it hard to snap it out. The felt pad is cheap enough to replace if there is any fluid on it.

If I had a ordered a slave cylinder I would be much better off when we did mine. Only now I realize how timely it was doing the weep hole procedure was. The upside is with these instructions I know I won't forget anything..

[varoom]

Kevin,

All I can says is WOW - excellent write up! Now I almost think I can do this :eek:. Thanks for the time & effort to compile this. Paul Seyegh would be proud.

[Hilton]

Thanks Kevin. This mod planned for the near future and your write up is excellent ! Been steadily collecting the required tools and now with your pics and text will incorporate the work into my replacement shock job too. Cheers

[blouw]

Good job, Kevin!

Wish I had this when I replaced my gearbox with a good used one.
Tip I got from our local BMW tech when I asked him about the magical lube that BMW uses on the rubber boot - he says he just uses Vaseline! Not sure whether grease would attack the rubber.

Second the idea of the specs for the 30mm tool. I have had a few requests for specs myself as I made one using David Shealey's as a model. I see that you used an impact socket. Not sure many people will have the tools to cut that. I used a chrome-type deep socket and with a bit of patience (and quite a few heavy duty cutoff discs) managed to cut a window with a Dremel.

I will be doing a clutch on my bike this weekend if the parts arrive, so will get to see it all again :D

[wildwestrider]

Great write up Kevin....I know from experience,...it takes great patience when doing something like this to take good pictures and notes then later put it all together in a professional write up like this. I frequently think of doing it,...but generally just want to get the job done ASAP,....so blow it off. I have managed it once on another forum or two. And still have my Krylon Dull Aluminum paint tip and 2x4 bead breaker tips on IBMWR.....but they were just a picture or two and a short narrative.............Kudos for going the extra mile.

A few Questions:

Since The final drive has to come out for this procedure,.....would it make sense to go ahead and replace the components that typcially cause FD failure?

How much more would be involved in changing out the clutch assembly at the time of doing the slave cylinder drilling mod?

Brian in Austin

[kevincook]

Brian,

Thanks for the compliments.

The clutch is a lot more work and more complicated than what is required to drill the slave cylinder. You can easily do the slave cylinder in an afternoon but it is several days of work to get the clutch replaced.

Also, I think the general opinion is that if the final drive isn't broken then disassembling it to replace the bearing may cause more problems than leaving it alone. Most people think the problem is an assembly problem more than anything else.

Good Luck,
Kevin

[wildwestrider]

Thanks Kevin.

[ncrozer]

kevin you are the "man" brilliant cheers mate

[sully2028]

Kevin,

Your procedure is excellent. BUT will you update it after considering the comments given above?

[jimbobmw]

This was an excellent write up. Thanks.
I am patiently waiting for the new LT as well and trying to keep my champaign
1999 on the road in the meantime

[razman10]

Having recently purchased my LT used, is there a way that I can tell if this has already been done without going through the whole procedure?

[Steve_R]

Ray it will be tough. Most dealers won't do this procedure on the LT. The only way to know for sure is to ask the previous owner. You might be able to see the whole on the bottom of the casting where the clutch slave sits, but I think you'll need to remove the right hand side tupperware and use a mirror and a flashlight.

[razman10]

Thanks Steve...

I will have the Tupperware off over the winter doing some regular maintenance. I'll see if I can see it and if not I might just try the procedure given those great instructions!

[kevincook]

Ray,

Just look from underneath the bike. The hole is drilled from below and you should be able to see whether a hole as been drilled or not.

I'll try to remember to take a picture when I get home.

Good Luck,
Kevin

[dshealey]

Ray it will be tough. Most dealers won't do this procedure on the LT. The only way to know for sure is to ask the previous owner. You might be able to see the whole on the bottom of the casting where the clutch slave sits, but I think you'll need to remove the right hand side tupperware and use a mirror and a flashlight.

You could use a mirror and light to look up. It can be drilled from below, so it can be seen if you know where to look. You will see the slave cylinder, and the hole is drilled in the transmission boss it bolts onto.