The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Bob_Roller on November 11, 2010, 11:51:03 AM
-
I was working on the rear brake on one of my R65's on Monday, finally got the problem with the rear brake solved, the brake shaft was incorrectly marked .
I removed the arm a few times and tried different positions until I got it right, then tightened things up, good to go .
This morning I went to move the bike and there is a small puddle of gear oil under the rear wheel, it's coming out from the gap between the final drive housing and rear wheel .
With me messing around with the brake shaft, I guess that when I put it back the last time I inadvertently pushed the shaft in to where the o-ring inside the brake drum area wasn't sealing very well, a tap with a rubber mallet pushed the shaft back to where it's supposed to be .
Something to remember if you mess around with this shaft with the rear wheel still on .
-
Bob, did you tap it towards the left side of the bike OR tap it, from the inside of the wheel hub, towards the rightside? I think I just pushed the brake actuating arm in as far as it goes to the rightside and it is then flush with the brake arm when all together. But.....
I am wondering now what I should be lining up, matching or whatever when putting that brake actuating arm back on. I have been just following my instincts! What should I be watching for? Other than lining up the punch marks.
If I remember correctly, it is impt. to keep the wheel off so that you have access to the left side of the brake actuating arm to be able to tap it towards the rightside as it WILL shift left when you push to mount the left side's brake shaft over the arm's splines. There is a fair bit of play right? So maybe that's what pushes those O-rings out of place?
Also, I have a vague memory that there is an adjustment of the rear brake's foot pedal well hidden in behind your heel area. It is ususally dirty with old grease and a bit finicky to find the adjustment nut there. This can be adjusted to help, I think, when you are running out of rod threads etc. or you're having difficulty getting the rear arm in a 90 degree angle for best efficiency. Do these memories trigger any thoughts from anyone?
-
I tapped it from the inside and it did move more than I thought it would .
The only mark, I have is on the brake shaft, I line it up with the gap in the brake arm .
The adjustment at the brake pedal, is for adjusting the rear brake light switch .
Now, I have another leak, it looks like it is coming from the final drive to swing arm gasket/joint area, I got out the torque wrench and tightened it to the upper limit, each nut only moved at best a half revolution, hopefully that will solve problem .
-
I'm a little late arriving at this party so my tip may be after the fact. Anyways...
To avoid having to remove the rear wheel in order to replace the rear brake arm on that pesky splined and "movable" rear brake cam shaft, press the blade of a thin putty knife against the cam shaft; right next to the final drive case. Blade between the case and the felt washer. Felt washer? [smiley=happy.gif] There's a shallow groove similar to the groove for the locking bolt- right at that point.
Hold pressure on the blade as you refit the brake arm. The final fit of the security bolt will take up any remaining bit of slack and result in the brake cam shaft being correctly positioned in the brake arm.
I hate having to yank the rear wheel for such a simple chore as positioning that brake arm. :P
Monte
-
I have a pic of LRB's brake actuating splined shaft all mounted in the brake arm from a while back and the punch marks are opposite to what I see now on the bike! In one case the dot is at the bottom of the shaft and in the other the shaft dot is at the top, in alignment with the gap on the arm! Does this mean there is a top and bottom of the actuating shaft as it goes through? I sorta figured you could push that shaft through any way you want. The dots were on the shaft just to help get the arm on in the position you liked it before it was all taken apart? (looking for the 90 degree best position).
So bottom line....did I push the O-rings out of position by not doing what Monte just said above or does the shaft have to be twisted around 180 degrees?
-
If your brake works fine and you have no leakage, I wouldn't mess with it .
As far as I could tell when I had the rear wheel off, the small lobes on the brake shaft that push on the brake shoes are the same shape .
I think the marks are there to be sure you gets things put back together kinda close .
-
I believe, Sue, that the cams on the brake shaft are symmetrical, I far as I can tell from my observations. Doubt if you have a concern with it being "flipped". I also believe that if there was a right-wrong way, you would be experiencing some "issues" with braking performance.
When I replaced the O-rings, my concern was having them get nicked as I pushed the brake cam shaft into the final drive case. I oiled up the O-rings and sorta rocked the shaft as each ring entered the passage. The edge of the hole looked rather sharp so I went slowly. Of course, there's a second sharp edge once you get past the self-oiling reservoir gap. Slowly...
Also, I believe that many of our R65s may have had previous owners add their "chop" to parts as an aid to refit. Some of these guidons may be helpful while others could be less so.
Monte