The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Ethan F on September 22, 2024, 02:04:52 PM

Title: Leaking at cylinder base after 4 install attempts - any suggestions
Post by: Ethan F on September 22, 2024, 02:04:52 PM

‘79 R65 with o-ring groove and o-ring housings in top of cylinder. I have cleaned spread thin layer of holymer blue, been careful to not squish the small o-rings. Pushrod tubes are set 5mm below cylinder base surface. I have tried with the 2.2mm o-ring and also with a 2mm o-ring. Torquing to 28nm. After torquing there has been a small gap that I can get a feeler gauge into.
When I turn over the engine oil comes out mostly from the top and seems in region of top studs where the little o-rings are.
I am wondering if I should be getting irritated? Will that help?
I am thinking that the next attempt will be with no large o-ring.
I have done lots of interneting on this and so far it seems I am the only one who has failed like this.
Please offer any suggestions.
Thank you.

Title: Re: Leaking at cylinder base after 4 install attempts - any suggestions
Post by: Bob_Roller on September 22, 2024, 03:49:35 PM

The pushrod tube seals where they go into the case are tapered and only go one way .You may want to adjust them a little to where they go in a little further .

Title: Re: Leaking at cylinder base after 4 install attempts - any suggestions
Post by: dogshome on September 23, 2024, 12:10:47 AM

Did you fit some new parts, or is the bike new to you and already leaking?

What caused you to remove the cylinder (s)?

Title: Re: Leaking at cylinder base after 4 install attempts - any suggestions
Post by: Ethan F on September 23, 2024, 11:01:45 AM

Bike was new to me. I dismantled to repair leaking at pushrod tube seals so new tube seals and o-rings.

Title: Re: Leaking at cylinder base after 4 install attempts - any suggestions
Post by: dogshome on September 25, 2024, 01:52:30 PM

OK, so could something not properly replaced before you got it. Understood.

Title: Re: Leaking at cylinder base after 4 install attempts - any suggestions
Post by: georgesgiralt on September 26, 2024, 12:51:29 AM

Hello,
Are you sure you have got the proper push rod seals ? Because the one for the R65 are a bit different from the other airhead one due to the fact that stroke being less, the angle made by the push rod tubes is different from the other airheads.
Also triple check that each seal is properly seated and oriented as these parts have a somewhat complex form.
Hope this helps.

Title: Re: Leaking at cylinder base after 4 install attempts - any suggestions
Post by: Ethan F on September 30, 2024, 12:21:59 PM

I ended up just using the supplementary cylinder base gaskets which worked. I did not include the big o-ring as each time I took it back apart the o-rings were pinched. There is a groove for these o-rings on the cylinder. It seems they were the culprits in not allowing the cylinder to mate with the engine housing. Weird. Could be operator error.
Anyway, I let’s see what kind of mileage the gaskets do.
Thanks for your suggestions.

Title: Re: Leaking at cylinder base after 4 install attempts - any suggestions
Post by: dogshome on October 02, 2024, 04:10:14 PM

Thanks for feeding back  :thumbsup: