The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: disco51 on February 22, 2014, 07:38:04 AM

Title: Pushrod tube collars adjustable on pre 81 bikes?
Post by: disco51 on February 22, 2014, 07:38:04 AM
Unfortunately, I have a bad leak from one of the pushrod tube seals.  The other three are completely dry.  Looking at the pushrod collars, the one that is leaking does seem to be seated farther back than the others.  Reading snowbum's article, he seems to state that post 81 collars were brazed on the pushrod tubes.  Does anyone know about the earlier bikes?  I didn't notice if they moved when I took off the jugs.  I'm hesitant to try to push this one in, but my only other option would be taking everything back off and get a new o-ring and pushrod seals.  
Now for the truth part.  I did initially install the pushrod seals backward (wrong end in the hole) for about 12 hours.  So, I'm guessing I could have damaged the seal or worse, moved the tube collar back.  I flipped them around and corrected my mistake, but that is in play as well.  
I'm guessing the best thing to do is take it apart again and redo the work… thoughts?
Title: Re: Pushrod tube collars adjustable on pre 81 bikes?
Post by: disco51 on February 22, 2014, 07:49:04 AM
Clymer also describes seating the pushrod tube seals with a tool you can fabricate.  I can't seem to visualize how this works.

Ahh the joys of being a basic mechanic...
Title: Re: Pushrod tube collars adjustable on pre 81 bikes?
Post by: montmil on February 22, 2014, 08:17:52 AM
The pushrod tube tool can be made from a piece of PVC pipe. However, if your tubes have the brazed-in-place rings, you'll possibly damage the tube by breaking loose the ring. Danger, Will Robinson.

http://www.bmwr65.org/htdocs/yabbfiles/Attachments/pushrodseal_Tool.pdf

Your statement about installing the seals backwards and now having "a bad leak" could well indicate damage to the seal. With your 1979 R65, only close examination of the tube rings will determine which style you have.

The issue is frustrating. Let us know what you decide to do.
Title: Re: Pushrod tube collars adjustable on pre 81 bikes?
Post by: disco51 on February 22, 2014, 09:43:48 AM
So where do you put that tool?  Thanks for the pic, but it's not clear to me how to use the tool.
My understanding was you might be able to use it while the jugs are on the bike, but maybe I'm mistaken.
Title: Re: Pushrod tube collars adjustable on pre 81 bikes?
Post by: montmil on February 22, 2014, 11:08:12 AM
Granted, an isometric drawing would provide a better visual. You'll have to hold the tool at an angle. The end is placed against the p'rod tube ring and, by working it around the ring as best you can, tap tap, tap.

You might not want to try this tool with the head off the bike as the pushrod tube could be knocked out of alignment to the crankcase opening.

Inspect your tubes in situ with a bright flashlight. Look for a small brazed spot on the ring surface that faces the heads. It's not brazed all the way around.

But first, confirm what type ring is an your bike.
Title: Re: Pushrod tube collars adjustable on pre 81 bikes?
Post by: Tony Smith on February 22, 2014, 05:47:45 PM
Quote
But first, confirm what type ring is an your bike.

As far as I know, ALL R65s have the sweated on or brazed on pushrod tube collars - this was IIRC one of the design improvements featured so as to avoid the exact problem under discussion.
 
Replacement pushrod tubes for other airhead models tend to be fixed as well.
Title: Re: Pushrod tube collars adjustable on pre 81 bikes?
Post by: disco51 on February 24, 2014, 08:41:21 AM
So... being pissed at the thought of having to redo this project, I took the bike out for a nice ride this weekend before it would go back in the shop for awhile.  Beautiful weather - mid 60s, sun shinning.
Rode fine.  No troubles.  New Emgo peashooter mufflers a bit louder than the BMW knock offs I had.  Smooth ride.  Parked it away that afternoon.
Leak is now completely gone this AM.  
Huh?
Title: Re: Pushrod tube collars adjustable on pre 81 bikes?
Post by: montmil on February 24, 2014, 10:59:25 AM
Rubber seals got toasty warm and re-conformed to the required shape. Winner!

I have the EMGO Pea's on the '83 and EPCO stainless ones on the '81. Love the tunes they play.