The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: dav on October 11, 2019, 08:49:39 PM

Title: Front brake
Post by: dav on October 11, 2019, 08:49:39 PM

Hi guys/gals,

Iam having a hell of a time bleeding the the single ATE front brake after a total rebuild of the brakes, new reservoir/o ring, M/C kit (12mm), stainless brake line, caliper kit & new caliper pistons. The M/C has 2 holes (looking down into it from the reservoir) but looking into the bore it has only one visible hole. Does the 12mm M/C have 2 holes or one? I gave the hole a lite tap to see if it was crusted over but it seems quite solid.

Thanks.

Title: Re: Front brake
Post by: Barry on October 12, 2019, 06:58:41 AM

There should be 2 holes in the reservoir.

On a complete rebuild like that I fill from the bottom upwards using a large syringe connected to the bleed nipple. When I've done it that way there has been hardly any air to bleed out as it pushes the air out as you fill. 

When I'm just changing fluid I garavity bleed as it works well on a front brake. Just open the bleed nipple and let the fluid flow under gravity. If you keep the reservoir topped up there is zero chance of introducing air.

Title: Re: Front brake
Post by: dav on October 12, 2019, 12:35:29 PM

Thanks Barry,

I might have to give the hole a few solid hits, the brake system has't had a good work out for many years, well besides a slow run in the back yard once in a while. I want to get the brakes sorted first and then move onto oils/tyres etc.. so i can get the old girl back onto the road.

Thanks.

Title: Re: Front brake
Post by: dav on October 12, 2019, 04:25:01 PM

THIS IS NOT MY M/C. This M/C is off a R65, this is what mine looks like regarding one hole (mine is not pitted like this one).

http://[url=https://davinshipton.smugmug.com/Just-pics/i-m98CCQQ/A][img]https://photos.smugmug.com/Just-pics/i-m98CCQQ/0/dc8d0aaa/M/IMG_0241-M.jpg[/img][/url]

Title: Re: Front brake
Post by: Bob_Roller on October 12, 2019, 05:33:27 PM

The smaller hole, looks like a conical well, that needs to be open for the master cyclinder to work correctly try putting a small diameter wire through it to clear it out .

When working properly a small jet of fluid will come out of the small hole when the brake lever is released .

Title: Re: Front brake
Post by: dav on October 12, 2019, 05:54:44 PM

Thanks guys all solved, i gave the 2nd hole a few solid hits and it broke through. It just looked liked it had no hole at all looking through into the bore. Now there is a lever to the front wheel after doing the bleed nipple bleeding method.

Thank you.