Master Cylinder Question

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Oct 2, 2008 | 06:35 PM

HDCopper

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Master Cylinder Question

The front brake master cylinder leaked and ate the paint on the master cylinder. I am planning on replacing the master cylinder with one I picked up on ebay for a really good price. A take off from a 2007 that was using Dot 5 fluid. I know that I need to flush it out in order to put it on my 05 bike that uses Dot 4. What would be the best solution to use to flush it out? Also do need to replace any other parts in the master cylinder such as seals?

Rob

Oct 2, 2008 | 06:45 PM

DGlide04

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From: Hudson Valley- NY

First thing to do is make sure that the master cylinder is the same. The RK takes a dual brake mc which should be stamped with 11/16 near the banjo bolt when you take it off. The single disc I believe is stamped 9/16" and won't work.

I'd flush it with new DOT 4 if that's what's going back in and yes, check the seals and all before you put it back together. Replacing them to be on the safe side is a pretty inexpensive proposition. MC repair kit is 45072-96C, cost is under $30.00 at discount, cheap peace of mind.

Oct 2, 2008 | 07:02 PM

HDCopper

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DGlide04, the master had Dot 5 in it when it was taken off. I am currently using Dot 4 and will continue to do so. Thanks for the part # for the bebuild kit. I will go ahead and replce the seals to be on the safe side. You wouldn't happen to know the Part # for the rear master cylinder?

Thanks, Rob

Oct 2, 2008 | 07:07 PM

DGlide04

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From: Hudson Valley- NY

Quote:

Originally Posted by HDCopper

If you're looking for the entire master cylinder, the rear part # is 41755-99B (MSRP- $83.00, about $64.00 discounted) and the rebuild kit is 42382-87C (MSRP- $60.00, about $48.00 discounted). For the small price difference, it might be a better deal to buy the entire rear MC fully assembled.

These are from my 2004 Touring parts book but I think they're the same as the ones on your 2005.

Oct 2, 2008 | 07:44 PM

dawg

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Unless the person changed it, it should be DOT 4 as HD used/uses DOT 4 since 2005 in tourers

Oct 2, 2008 | 09:02 PM

HDCopper

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The person I am buying the front master cylinder from stated that he was using Dot 5 fluid in it before it was removed, so I want to flush it out in order to not have any issues.

And is there a difference between a rebuild kit and a repair kit? If so which one should I need to complete this project? I would think just the seals. I am also replacing the rear master cylinder for the same issue, Dot 4 fluid is nasty stuff. I appreciate all of yalls help with this.

Rob