Gasket on the Clutch Master Cylinder

Question for Fix My Hog Hello, I have a question about my October built 2007 NRSCDX. I have had to changed the gasket on the clutch master cylinder several times now over the last six years and it still starts to leak after about 12 months. It has even been changed by HD hopping they used the right torque setting. I have even gone as far as using a fine abrasive paper on a block to clean the surface up now the latest gasket has now failed. HD want about AU$230 for a new clutch master cylinder and leaver setup. the fluid is now running down to the pin that secures the leaver in place. So can anyone help me out with any information on how to fix this problem, besides the obvious one of purchase a new setup… Thanks in advance.

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Fix My Hog Answers This is a very common issue with many Harley clutch & brake master cylinders, not only V Rod. Seems to be more of a problem since they have gone over to DOT 4. A light mist of brake fluid begins to seep through the small vents (slits) in the top cover. There is typically one vent on the front and one on the back. After a while the DOT 4 softens the gasket on the clutch master cylinder and the seep, eventually, turns into more of a leak. If your master is black, the paint peels and it looks awful. It is a poor design and not very much you can do. You can upgrade to chrome controls. Then you do not have the issue of paint peeling and it is an easier clean up. If you want to consider a different master, consider Performance Machine. Unfortunately, your options are: deal with it; or spend a considerable amount of $$.

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5 Responses to “Gasket on the Clutch Master Cylinder”
  1. Joseph
    Joseph

    I would like to know how to bleed my brakes on 2015 Street Gluide with ABS. I have new chrome break lines from Harley front and rear.

    Reply
  2. Joseph
    Joseph

    I do a lot distance riding and I have been playing around with this problem. First of all I have 4 vents in my gasket for the front brakes, one on each side. I put tape over the front hole & the left, inside, hole. I’m not seeing that much weepage anymore. The front brakes feel good still, AND WORK! I’ve been doing this for the last 5K+ miles and I am seeing a difference. I’m I creating a problem doing this???

    Reply
  3. Charles
    Charles

    The fluid seeping out the vents are not normal, usually it is caused by an overfilled master cylinder or a master cylinder that is not orientated correctly during operation. These master cylinders are designed to be operated at an angle parallel to the ground however some people prefer their controls slightly angled and some rotate the controls to suit their build (arm length) thus causing the master cylinder to be off parallel to the ground. The slits are just for venting air into the top of the diaphragm so that you will maintain brake pressure as the fluid level goes down due to pad wear.

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