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Replacing Clutch Bleed Valve/Nipple

11K views 8 replies 4 participants last post by  Hoggy  
#1 ·
Thought id put this simple how too together as its an easy fix to something that may seem like a more complex problem like the master cylinder going which a DIY job but fiddly or the slave cylinder which is in the gearbox so is a massive gearbox out/replace clutch while doing so job. I'm not that familiar with the TT yet so please correct any of my assumptions/explanations.

Tools

Small thin flat blade
bottle nose players

items needed

new bleed valve (ÂŁ30)
1lt brake fluid (ÂŁ3.99)

Symptoms

Clutch goes straight to the floor and dosent return.
Clutch(Brake)Fluid seeps down over starter motor onto grounds below battery area.





Investigation

If you have fluid on the ground you will have lost some from the brake reservoir as the clutch feeds off the top of this and the brakes off the bottom. Open up the reservoir and fill with new fluid. If you have someone with you get them to pump the clutch manually while you observe the bleed nipple from above in the engine bay. This can be located by looking down the left hand side of the battery.



If your on your own either position your phone to record a video looking down or wait until there is no more dripping and then pump the clutch by the time you run round you should see the fresh fluid dripping down. If you can observe from above and you see fluid coming out of either side of the bleed nipple then this may be a strong indicator to a failed clip on the nipple. In my case the clip had rusted through and a part broke off so there was not tension in the connector joint so fluid was escaping out the circled.



Fix

Once you have a replacement bleed valve you can proceed with the fix. I found it more manageable to remove the old valve by removing the battery first this allows you to lean down into the engine bay to get to the clips. It may be possible to do this fix with the batter in place. So once you get access from above i found a small thin flat blade was the best to get under the clips to pry them up. You will have to attack them from the sides but there is just enough room. Once they are up a bit either get some bottle nose pliers on them or get the blade under them and pull the clip up to its maximum. If you look at the new bleed valve this will give you some idea of where this should be.

once both clips are up remove the clutch pipe on the right and then force the bleed valve out the housing by pulling on the right hand side of the valve and pushing on the stem of the nipple from the left hand side. it should just pop out. Below is a comparison of my new and old showing the failure.



The valve is keyed so it can only go into the housing one way. So with the notch on the left present it to the housing and push into the housing tube from the right. make sure it is pushed in all the way as this library pic shows.



once this is in and you push the clutch pipe back in on the right hand side push the to clips down to snap into there locating slots and that should be you. Put some more fluid in the reservoir and pump the clutch again to check you have no leaks. If all is good then you just now have to bleed air out of the line. If you still have leaks then the O-rings may need replacing on the pipes that connect to the bleed valve.

Bleeding

This topic has been covered many times but ill explain my approach having bleed bike brakes many times. You have the master cylindrical (under the pedal) connected to the the slave cylindrical (in the gearbox) with a pipe that has the bleed valve in the middle. You now have introduce air into the system. As i was just myself i eventually opened the bleed valve and put a rag over the top of it then pumped the clutch by hand ALWAYS ensuring the reservoir was full to the brim. This eventually pushed all the air out the system and then the clutch firmed up. close the bleed valve and brim the reservoir and fit cap back on. I may have got lucky here so you may prefer using one of the more conventional approaches.

Im still keeping an eye on things but everything seems good so far.
 
#4 ·
Hi,

I think my bleed valve is also shot, appears to be drawing in air (well thats what I'm hoping). I have two questions though after reading your write up;

Where did you purchase your bleed valve, dealer, eBay ??

Having read your bleeding procedure I'm surprised you didn't introduce air into the system if you left the bleed nipple open after every pump of the pedal ??

Keith
 
#5 ·
keithriley said:
Hi,

I think my bleed valve is also shot, appears to be drawing in air (well thats what I'm hoping). I have two questions though after reading your write up;

Where did you purchase your bleed valve, dealer, eBay ??

Having read your bleeding procedure I'm surprised you didn't introduce air into the system if you left the bleed nipple open after every pump of the pedal ??

Keith
i got it from TPS. because the nipple is in the middle then thats is where the air would be so i pumped the pedal and refiled a few times untill the pedal stiffened up then hard a few times more to expel any air and quickly shut it off. As said i may have got luck but it worked for me.