Author Topic: Brake Master Cyl  (Read 2716 times)

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Offline davecumbria

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Brake Master Cyl
« on: April 07, 2012, 12:40:02 PM »
Noticed today that the master cylinder is leaking quite heavily around the joint around the reservoir. It seems to build up in the small gap between the reservoir and the base, and blow out onto the bracket and splash the tank when the bike is in motion.

will have a more detailed look tomorrow
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Offline RDnuts

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Brake Master Cyl
« Reply #1 on: April 07, 2012, 12:51:15 PM »
this type of master cylinders are prone to do this the   b ones do it as well there is a seal located near the bottom of the cylinder this shrinks over time a right bast@rd if the fluid goes over yah paint work or you lay the bike up and it runs all over the place   
RDnuts 18 RDs tooooo many even for me , the best things in life aint free, non fully paid up x member 2376 owner and restorer of the first rd to come to the uk RYN51L front page of april 2013 classic bike my claim to fame

Offline Welsh_Dragon

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Brake Master Cyl
« Reply #2 on: April 07, 2012, 04:40:07 PM »
And its just passed its MOT  
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Offline Paul Dawkins

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Brake Master Cyl
« Reply #3 on: April 08, 2012, 01:36:29 AM »
The MOT was over a week ago................

The front and rear brake was pressed 3 times and checked for leaks and there was nothing visable.
Thats not to say its not leaking but stood still and  and checked there was nothing visable.






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Offline SupeRDel

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Brake Master Cyl
« Reply #4 on: April 08, 2012, 04:06:31 AM »
Never noticed any leaks there when I had it for a month.

I did find that it was spitting oil out of the exhausts though.

Did this too my boots after a 50 mile ride.





Some of these oil spots made it up onto the tank as well.
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Offline Paul Dawkins

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« Reply #5 on: April 08, 2012, 05:04:16 AM »
Looks like its spitting feathers Del
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Offline RDnuts

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Brake Master Cyl
« Reply #6 on: April 08, 2012, 01:56:42 PM »
you sure you was not riding a british bike there del or you have just had a hit&miss
RDnuts 18 RDs tooooo many even for me , the best things in life aint free, non fully paid up x member 2376 owner and restorer of the first rd to come to the uk RYN51L front page of april 2013 classic bike my claim to fame

Offline davecumbria

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« Reply #7 on: April 08, 2012, 03:20:10 PM »
So stripped the master cylinder off the bike (carefully), removed the reservoir flatted off the base and removed the O ring cleaned up the base and carfully smeared some silicon around before refitting.

So its back on the bike, no fluid in yet, will leave overnight to set.

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Offline Paul Dawkins

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« Reply #8 on: April 13, 2012, 10:35:02 PM »
Good stuff Dave

Got any photos?

dont forget to record the mileage on here and in the book
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Offline davecumbria

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« Reply #9 on: April 15, 2012, 03:43:26 PM »
Ok so had a closer look at the underside of the cylider and there an amount of fluid that has leaked from the underside on to the headstock and although its difficult to photograph here are a couple of pics















Its actually very difficult to identify the source but as said I reckon its coming from the joint between the reservoir and the cylinder



Looking at the pic you can see the fluid level has dropped







this was the level once the diaphragm had been lifted out





So removed the cylinder from the bike and the reservoir from the cylinder, removed the O ring and gave it and the groove a good clean



Alsso flatted off the mating surface of the cylinder



 



A bead of silicon around the neck of the reservoir, carefully fitting and watching for excess being expunged from the joint



screws refitted and left to set







The cylinder was refitted to the bike the other night, the bike has been on a run today and I havent noted any re-occurence of the problem





Growing old is inevitable, growing up is optional

Offline Paul Dawkins

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Brake Master Cyl
« Reply #10 on: April 15, 2012, 03:52:32 PM »
Good job Mr Cumbria.



How was the ride today

Hope you have not changes all them nice shiney bolts for NOS genuine Yamaha.



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