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[solved]Front brake reservoir/cylinder issue Fri Dec 07, 2018 5:54 pm
kenrams
![kenrams](https://i.servimg.com/u/f41/11/71/56/74/avatar10.jpg)
Silver member
![Silver member Silver member](https://i.servimg.com/u/f80/11/71/56/74/bmw-2s10.gif)
Guys,
I recently purchased a neglected 86 K75 (44,000mls) and am working my through it. The front brakes didn't work and on taking the reservoir apart, I found a load of gunk inside and also inside the cylinder. I cleaned it up with using a piece of wire, brake cleaner, blasting air and finally an ultrasonic bath. It is now spotless and both holes are open as can be seen in the pictures below. Also, the piston, seals, and cylinder bore all look in excellent condition.
So why the post? When I fill the reservoir with fluid I get no output to the brake line when I pump the brake lever! There is no brake fluid escaping anywhere either. This does not make sense to me and can only guess that the rubber piston seals are not as good as they look. Do I need to buy a rebuild kit (new piston and seals) ?
Cheers
Ken
![[solved]Front brake reservoir/cylinder issue Pc070110](https://i.servimg.com/u/f87/19/23/86/73/pc070110.jpg)
![[solved]Front brake reservoir/cylinder issue Pc070112](https://i.servimg.com/u/f87/19/23/86/73/pc070112.jpg)
![[solved]Front brake reservoir/cylinder issue Pc070111](https://i.servimg.com/u/f87/19/23/86/73/pc070111.jpg)
I recently purchased a neglected 86 K75 (44,000mls) and am working my through it. The front brakes didn't work and on taking the reservoir apart, I found a load of gunk inside and also inside the cylinder. I cleaned it up with using a piece of wire, brake cleaner, blasting air and finally an ultrasonic bath. It is now spotless and both holes are open as can be seen in the pictures below. Also, the piston, seals, and cylinder bore all look in excellent condition.
So why the post? When I fill the reservoir with fluid I get no output to the brake line when I pump the brake lever! There is no brake fluid escaping anywhere either. This does not make sense to me and can only guess that the rubber piston seals are not as good as they look. Do I need to buy a rebuild kit (new piston and seals) ?
Cheers
Ken
![[solved]Front brake reservoir/cylinder issue Pc070110](https://i.servimg.com/u/f87/19/23/86/73/pc070110.jpg)
![[solved]Front brake reservoir/cylinder issue Pc070112](https://i.servimg.com/u/f87/19/23/86/73/pc070112.jpg)
![[solved]Front brake reservoir/cylinder issue Pc070111](https://i.servimg.com/u/f87/19/23/86/73/pc070111.jpg)
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1981 R100 cafe- 121,000 miles
1985 K100 cafe - 55,000 miles
1987 K75C - 44,000 miles