Bleedin' clutch

[478cc]

I have 2 spare 10mm x 1.0 bleed nipples in my garage.
One of them has a pointed end (the end that screws into the caliper/bleed valve) and the other does not have the point but has a small dimple in the end as so is shorter.

I took out the grub screw in the clutch bleed valve and can see the ball bearing in the tube that prevents the fluid from coming out.
That grub screw was in TIGHT, I used the wife's hairdryer to heat the valve body and it eventually gave way with a very loud and worrying crack. I really thought I had broken something, but everything looks OK.

When I tried the bleed nipple with the pointed end, the point touches the ball bearing in the valve just before the threads start to bite, so I assume I need the nipple with the dimple in the end ?

This seems to work in reverse to a normal brake bleed.
ie I need to screw the nipple IN to get any fluid out.

Or do I screw it in far enough to push the ball back and seat the taper on the nipple and then remove it 1/4 turn to allow the fluid out ?

I think I am thinking about this too much and making it more difficult than it really is.

By now it was getting too dark to do any more tinkering and the only plastic hose I had was too large to fit the shorter nipple, so I put the grub screw back in. Will try again at the weekend.

Any one any tips ?

BTW My 'not so local' dealer parts man (see my post about home servicing) had no idea about the bleed nipple and had to go and ask a mechanic. He came back and told me he had sold the last one earlier that day.
Not sure how he managed to sell a part and then had no knowledge of what the part was later the same day.

[iowabeakster]

i think that you may be thinking too much, i think, maybe not.

put some anit-sieze on that grub plug next time.

[Sunbeemer]

Use the dimpled one in the clutch bleeder adapter to push the ball back, but carefully wrap a small amount of teflon tape around the lower part of the threads so fluid can't leak by them when you back it off 1/4 turn to open the valve to bleed the clutch. I made one like this from a SpeedBleeder by grinding the pointed tip off and it worked great.

[TicTac50]

BMW makes a special bleeder for the clutch.
I think I paid $6.00 for it.
Very easy to use. It goes in maybe 2 or 3 turns.
When it touches the valve the bleeding process starts.
You don't need to use the wrench. It goes in and out by hand.
Make sure you cover all the plastic parts in the front, and specially the left turn signal. That black plastic does not like the DOT4 break fluid.
Good luck.

[dougpaw57]

I just bought one of the bleed screws two weeks ago from Bob's BMW. The BMW part number is 34 21 2 330 310. It works like a charm.

[CycleRob]

The bleeder screw you get from BMW:

Clutch bleed nipple P/N 34 21 2 330 310 ----- $7.40

takes the place of the Aluminum assembly with the ball down in the tunnel. Shelve it. The bleeder screws directly into the end of the hose and it works good. You'll need a 10mm and an 11mm box wrenches to get a good grip on the soft bleeder nuts without distorting them. I put some Moly grease on the threads as repeated threading movements of a bleeding procedure will destroy dry Aluminum threads. Be aware that greased threads screw up torque values in that less hand wrench torque is required to get it just as tight. If you use the same torque with greased threads, you WILL overtighten it, possibly to failure. This is why the BMW manual warns you to (paraphrasing) . . . Do not grease (rear wheel) lug bolt threads.

[awagnon]

I removed the cylindrical thing on the end of the clutch bleeder hose with the ball valve in it and just replaced the whole thing with a regular bleed screw. Works fine and it's there the next time I need to bleed the clutch. It was hard to get off. I did have to heat it in order for the threads to loosen.

[frozennorth]

Or do I screw it in far enough to push the ball back and seat the taper on the nipple and then remove it 1/4 turn to allow the fluid out ?

Yup, that's exactly it, 1/4 to 1/2 turn with the BMW clutch bleeder nipple . . . part # listed above. Attach your Mighty Vac, or whatever vacuum device you are using and have your significant other, beer drinkin buddy, or responsible offspring top up the reservoir whilst thy vacuum's the dirty fluid. Works well. Put a little anti seize on the grub screw when thou hast completed the bleed Remember to also cover your tank and oil cooler covers with a garbage bag to keep errant drops of brake fluid from marring thy paint.

[478cc]

Well I finally got around to changing the clutch fluid tonight.
In the end I did as Al mentioned above and removed the ball valve completely and screwed the bleed nipple directly into the connector on the end of the hose.
Undid the nipple a quarter turn and pumped four resevoir fulls of fluid through the system. It came out remarkably clean which surprised me because I don't think it had ever been changed (it's an 03 bike).
Then got the wife to operate the lever while I undid the bleed nipple and bled the system like a normal brake circuit. Did this 2-3 times, no air bubbles and the lever is nice and firm.

Total cost for a bleed nipple and length of pipe to fit, just over £1.
Result

[awagnon]

478cc,

Good job. Your experience was the same as mine. Unexpectedly clear fluid came out. Still, I think it needed to be done.

Safe riding....