Rebuild heads? Or

[crouthier]

Hi, I recently posted asking about a head rebuilding service - and I got an answer...but I am now wondering IF I should do it.

I usually abide by 'if it's ain't broke don't fix it', but my '72 R75/5 has 1 leaking push rod seal - I did them about 5 years ago, not sure why it's leaking - could be something I did wrong..But i am going to do it again and thought, hey, if I'm going that far, why not rebuild my heads. My bike runs great with about 40k miles, valves are pretty consistent - there IS some change from year to year, but not dramatic and no oil burning / usage issues.

Do you think it's worth the extra effort/cost to rebuild my heads - will there be a big enough benefit and/or would I have to do it any way?

thanks for any thoughts.
Chuck

 

[stevenrankin]

Don't

At 40K of normal riding you don't need to have heads rebuilt normally. Your bike was not one of the years afflicted with the valve recession problems and unless you are finding you have to constantly adjust valve clearance other than the regular approximate 15K interval, you should not worry.

If the bike runs well, fix the leak and ride it. LOL that is a few hours of work versus a couple of days off of the saddle. St.

 

[crouthier]

St, thank you for the advice...makes sense. C

 

[stevenrankin]

Lol

I am sorry, I forgot, if you really want an answer, perform an engine leak down test. If your valves are shot, you will hear it quick. Where are you in NY? St.

 

[crouthier]

Hi St. I am in lower Westchester. A leak down test makes sense. Thanks! Chuck

 

[stevenrankin]

Cool

Yeah, just a bit too far away to be practical.

Don't forget to let us know how the leak down goes and what you decide to do. St.

 

[slowpokepete]

Hi St. I am in lower Westchester.

Port Chester, NY is where I grew up!

SPP

 

[9842]

Give it a wack!!!

Hi
I have an old tool that came with one of my /5's. Think of it as a small pipe with one end cut at an angle so it fits over the pushrod tube and sits on the metal part of the seal. A soft wack with a hammer on the other end of the pipe is supposed to snug up the seal. To hard a wack will over tighten the seal and it may split so find out a little more info on the tool and procedure before you try it ok. Its worth a shot (wack). If it works, great, if not pull the heads and change them.
Good luck
Brian

 

[20774]

At some point, the washers on the pushrod tubes were welded in place. Whacking on them could pull the pushrod tube out of the heads, maybe loosen them, creating another leak point.

 

[9842]

To wack or not

At some point, the washers on the pushrod tubes were welded in place. Whacking on them could pull the pushrod tube out of the heads, maybe loosen them, creating another leak point.

Hi
What little I know is /5 and /6 pushrods tubes have a press fit collar to hold seal. Later tubes are braised or welded so no Wacking on later tubes or it will move the tube along with the collar and pull other end of tube from head. That said the wacking procedure is a temporary fix until your next full service and the seals should be changed when service is due.

Back in the day in-between service intervals I would go to the shop and my mechanic would give it a little wack and say he would keep an eye on it until next service.

I have been riding BMW's since 1976 and I do not tinker with the engines. I only let experienced hands touch my engine and wiring. My motto is "learn from the mistake of others because you won't live long enough to make all the mistakes yourself". I do mostly everything else on my machines. I presently have 4 airheads, 88 R100RT, 72 R75/5 curry toaster, and two Green and Blue lwb R75/5 toasters.

Most of us brag about how simple airheads are, but I find these machines require a special skill to work on them. Do your homework and decide if the Wack is worth a try.

Let us Know what you decide and how it turns out.

Good luck
Brian