Everything

[wxp]

Hey Folks, A couple of things..

Fst..the master cylinder was leaking, replaced the piston, cleaned it all up, should be ok from here, haven't ridden bike in several weeks due to leaking master cyl..the brake lights don't work when using the front brake lever, is that the switch in the little transfer block??  Also, are there any replacement rubbers for the piston rather than have to purchase the entire piston??


2nd & more important at this time, there seems to be some seepage where the jug contacts the block..I read when adjusting the valves the head should be "re-torqued"  does that mean loosen the head bolts the re-torque or simply check the torque on the head bolts?? If I "re-torque" the head that is seeping oil will it stop?? or am I going to have to replace that gasket.

Thanks for the input ahead of time

Bill

[Bob_Roller]

There doesn't seem to be any replacement seals available to the general public for the master cylinder, I've searched and pretty much came up empty .

If the oil leakage/seepage from the cylinder base is coming from the cylinder itself and not the push rod tube seals, tightening the cylinder will not do anything to stop the leakage .

There is an o-ring on the cylinder base that do the sealing, like I said no amount of tightening the hold down nuts will help .

If you have a '79-80 model year bike, the front brake switch is located on a  splitter under the fuel tank, the '81 and later bikes have a switch at the front brake lever .

[Bengt_Phorqs]

The front brake switch is on the front brake perch.  There are two small wires with small spade connections.  Not uncommon for them to break or come loose.  Check the wires.

Can't speak to the m/c piston.  Check the microfiche available from Max BMWs website.  Perhaps someone on the forum who has repaired a m/c can weigh in here.

Regarding the leak around the jugs, it could be just grime that builds up.  Before doing anything drastic I would first clean it up, then take a ride and see if it forms again.  It is does, the do a search on this forum about retorquing cylinder heads.  It's been addressed many times.  Very easy to do, but you want to do it correctly.  Replacing the gaskets is not a difficult task if that's what is needed but there are some specific steps required.  Again, do the search and you'll find the information.

Good luck!

[montmil]

Some "weepage" is not uncommon at the cylinder / crankcase join. If it's a big mess leaking, then, yes, you may need to replace the O-ring at the cylinder base. Of course, that means pulling the jug off the piston and that means new head gaskets, too. Then there's the small O-rings for the pushrod tubes. You may also want to check the rubber grommets where the pushrod tubes mate with the crankcase. With all things off, it's a good time to replace the grommets.

Before yanking everything apart, make up a shopping list of of needed gaskets and O-rings. Nothing worse than being down-checked while waiting on parts.

Motobins http://www.motobins.co.uk/ is tops for parts and fast service.

Monte

[Rob Valdez 79 R65]

wxp - what year is your R65?  It makes a difference on the front brake assemblies, as well as other parts.

I usually replace the big o-ring at the base of the cylinder whenever I have it off.  same goes for the two small o-rings on the top studs, and the push rod tube seals.  There is no base gasket.

Make sure you have a good, accurate torque wrench for the studs.

[wxp]

Thanks for all the input..

The bike is a 1980 model..

When I rode it this late afternoon I noticed some new wet seepage. I had wiped it prior to riding it.. guess I'll be doing that this winter..wanted to ride it to BNA in the coming weeks, My great Aunt, 102 yrs is on her last leg might have to go for the inevitable, bummer on both issues.

[Rob Valdez 79 R65]

Replacing the brake light switch is no big deal, as long as you don't mind bleeding the system afterward.

You can always get around it by applying your foot brake at the same time, providing it's switch is working - AND - you remember!

(add the year of your R65 to your signature line!)