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1978 R80 pushrod tube seals

N

nickrides

Nick Kennedy
Hi All
Can any one help me out with a parts list I need to replace the pushrod seals please.
I obviously need the 4 pushrod seals, what else? Is there a gasket under the cylinder that needs replacing?
What else? I will leave the head attached to the cylinder.
Also can any one give me a link to those repair videos, I think the guys name is Chris ? The guys that drops alot of f bombs ya know!
Thanks in advance
Nick Kennedy
 
Nick -

Check my signature line link for a section on this...other websites out there. I personally like Oak Okleshen's top end manual...pretty cheap and still available from his estate. His email address is in my signature line link.

Are you going to pull the head-cylinder combo off the studs? Note there are two small O-rings that are on the upper studs and really should be replaced. You will need to scrupulously clean the engine base and cylinder base and use a sealant. Mind the upper two studs have an oil path from inside the crankcase to the upper studs...this is how oil gets to the rocker arms. You don't want to plug those holes.
 
Hey Boys Thanks for the advice and video links, I'm going for it!
The dripping has reached it limit for me to tolerate.
I'll let you know how it turns out, I'm sure it will be fine,
I love that R80, she is a sweet bike to ride!
Right now she has Avon Roadrider tires on, those are great BTW! Easy to take on or off by the side of the road, I know I've done it. Those Michelins are great tires, but I don't think I could take them off to fix a flat on the side of the road, just saying.
 
I would replace all these parts:

base gaskets
rocker cover gaskets
O-rings
push rod seals (and I would also use a little hi-temp silicon sealer on these - just a light film)
I also liked the factory BMW gasket sealer for the base gaskets/Orings. I purchased a tube from Max's BMW. A tube would last a lifetime.

Also, while in there, decarb the top of the pistons and the insides of the heads. When pulling out the cylinders, make sure that the piston/rings assys. do not fall down onto the bottom studs. I used some rubber tubing on the studs (sliced end to end so that they could be pulled off while getting the cylinders started back on and back over the pistons) to make sure that the pistons are protected, or a soft piece of wood across the studs to hold pistons up while cleaning/servicing the other stuff.
 
It's important also to not let the conrod fall and hit the engine case opening.
 
SCBuckeye said:
I would replace all these parts:

base gaskets
rocker cover gaskets
O-rings
push rod seals (and I would also use a little hi-temp silicon sealer on these - just a light film)
I also liked the factory BMW gasket sealer for the base gaskets/Orings. I purchased a tube from Max's BMW. A tube would last a lifetime.

Also, while in there, decarb the top of the pistons and the insides of the heads. When pulling out the cylinders, make sure that the piston/rings assys. do not fall down onto the bottom studs. I used some rubber tubing on the studs (sliced end to end so that they could be pulled off while getting the cylinders started back on and back over the pistons) to make sure that the pistons are protected, or a soft piece of wood across the studs to hold pistons up while cleaning/servicing the other stuff.
Click to expand...

This sounded wrong to me so I checked Oak's Top End Manual. He (and Tom Cutter and Snowbum) do not recommend using sealant of any kind on the large base O Rings or the push tube seals. These are prepared with clean engine oil and only at the time of install. The oil causes these rubber parts to expand as they should. Once the O Rings are lightly covered in oil you need to assemble things pretty quick or assembly becomes difficult due to swelling.

For the base of the cylnders a very light film of Hylomar or Permatex Ultra Gray or Pro-Seal Red Silicone 700 deg F or... some high temp, flexible, easy to remove sealant intended for this purpose. I've used Permatex Ultra Gray twice now with no leaks. Be very careful around the top stup crankcase openings. Too much sealant can block oil flow through here which is critical to top end lubrication.
 
I just did this on my 75/5, it doesn't have the O-rings, but otherwise similar. I separated head and cylinder though and also removed the piston since I did have to re-thread a stud.

On the base I used a new gasket with a tiny amount of the grey sealant (Honda product). Careful not to obstruct the oil bores.
New gasket on the head, no sealent
New valve cover gasket.

All tight and no issues, don't forget to re-torque the heads and adjust valves after a while as recommended by the pros. Mine really needed it!
 
The OP indicated that he intends to leave the head attached to the cylinder when renewing the pushrod seals. This means that the 12 and 6 o'clock nuts will remain on the studs. Personally, I would slightly loosen these nuts (about 1/4 turn) just to relieve some of the tension on the studs, but not enough to disturb the head gasket. The head gasket is usually the most expensive component in pushrod seal renewal if the head is removed. If the head is not removed, barring other issues, the process can be done in a few hours fairly inexpensively.

An exception is having to replace the exhaust nut. This is illustrated in the video from the Illinois BMW club. A stuck exhaust nut can be removed without incurring more damage to the threads on the head.

Not fully illustrated in the Illinois video is the removal and replacement of the clip securing the wrist pin in the piston. The fellow doing the video had to put the camera down to remove the clip and re-insertion was done in a manner that was not captured by the camera.

I found it somewhat difficult to remove and replace the clip the first time I undertook this operation. Somewhere in the house that I use to live in, in several dark recesses of the garage, are a couple of these little clips. I am glad that they didn't fly into the engine case. Subsequent removal and insertion efforts went much easier. It is a very good idea to block the opening to the engine case with cardboard, rags, or something to lessen the likelihood of the clip entering the engine case. I would obtain several extra clips and I do not re-use old clips. My removal and insertion technique involves use of a very small "minus" screwdriver rather than needle nose pliers (as sort of shown in the Illinois video. )

I use a reliable torque wrench and only torque the head bolts to 25 ft-lbs. I do the tightening in a cris-cross fashion (as shown in the factory and most other manuals). I apply torque in 3 stages, usually to 10 ft-lbs, then 18 ft-lbs, then 25 ft-lbs. The 12 and 6 o'clock nuts do not require nearly as much rotation as the other four nuts. When going to the 10 ft-lb torque I use a large C-clamp and a couple of appropriate sized sockets to slightly compress the rocker. I do this by feel. I do not want rotational movement about the rocker axis to be constrained, but I want minimal lateral movement.

I have taken to using Yamabond (aka Hondabond) sealer at the base of the cylinder. I apply a very light coat to both the base of the cylinder and the engine case; typically I use a gloved finger. Care should be taken to not block the area about the top studs by using excess sealer.
 
RE: wrist pin circlips. Just want kind of circlips are expected on this '78 R80? On my '78 R100/7, the clips were external c-clips, easily removed with the appropriate circlip pliers. So, I suspect the same with the R80.

However, upon installation of the Siebenrock kit to replace the worn out top end on my /7, the circlips were small sections of wire in the shape of the letter "C". These had to be pushed into the wrist pin hole until they popped into the keeper slot in the piston. That was relatively hard, and I'm not sure my thumbs have recovered! In the case of the my R69S, I had to remove and reinstall the "C" clips which ended up being doubly hard.

But for the '78, I wouldn't expect that much trouble.
 
On my 77 R100RS, 75 R60/6 and 71 R75/5 the wrist pins were all secured with the round wire in the groove outside the wrist pin. The first time was difficult; the fourth time was not difficult.

On my 93 R100GS/PD the wrist pin was secured by the traditional circlip that is easily removed with a pair of circlip pliers.

I have no idea about a 78 R80.
 
SCBuckeye said:
I would replace all these parts:

base gaskets
rocker cover gaskets
O-rings
push rod seals
Click to expand...

O ring on base of cylinder as well as o rings on the cylinder mount studs

Airhead rocker cover gaskets are good for ~10 years, so this may not be necessary.
 
20774 said:
RE: wrist pin circlips. Just want kind of circlips are expected on this '78 R80? On my '78 R100/7, the clips were external c-clips, easily removed with the appropriate circlip pliers. So, I suspect the same with the R80.

However, upon installation of the Siebenrock kit to replace the worn out top end on my /7, the circlips were small sections of wire in the shape of the letter "C". These had to be pushed into the wrist pin hole until they popped into the keeper slot in the piston. That was relatively hard, and I'm not sure my thumbs have recovered! In the case of the my R69S, I had to remove and reinstall the "C" clips which ended up being doubly hard.

But for the '78, I wouldn't expect that much trouble.
Click to expand...

In my past experience, though I can't remember how it was on any of my BMWs, when the piston/wrist pin situation had the wire "C" clip, the piston usually also had a notch which allowed for the removal and insertion of the clip much easier. I purchased a very small set of needle nosed pliers (good quality here, like Channelocks, not cheapies), which allowed me to grab the clip, and then work around it making sure that it didn't go "boing" and fly out somewhere where I couldn't find it!! Also, on that note, in my opinion, one should not re-use one of these or other style of clips. They are so inexpensive, that you should purchase new ones each time - and even buy extras in case you do have one of those "boing" moments!
 
Con Rod support

20774 said:
It's important also to not let the conrod fall and hit the engine case opening.
Click to expand...

I like to take two rubber bands and route them around both upper studs and through the connecting rod to keep it supported.
 
Here is an option that will save time...

I read the reply's and did not see anyone mention this:
Don't remove the piston from the cylinder. When the moment comes, pull the cylinder back from the block until you have exposed the piston pin. Your R80 will most likely have the style of pins that have groves for external snap rings that require snap ring pliers and are easy to remove and install. You can pull the wrist pin and remove the cylinder with the piston still in the bore. On assembly replace the old snap rings with new ones and pay attention to the rings edge. Keep the sharp edge away from the piston body when installing. the gap in the snap ring should go either up or down and should never be positioned in the direction of piston travel. If you find wire rings in groves in the piston remove them using a small pliers. Replace them with new as above. BMW sells a wire cir-clip I personally could not install. Way to stiff wire. Max sells the wire clips like the ones that BMW used in the earlier /5 /6 /7 and they are much easier to work with. These parts are one time use due to annealing of the spring steel during heat cycles.

By leaving the piston in the bore you eliminate the potential for breaking a ring, positioning the ring gaps wrong or scratching the cylinder and, with piston removed you would really need to rough the cylinder surface up as the rings will never go back the way they were which messes up your compression a bit. The chance of finding a big cylinder base O' ring installed in your bike is small. I've never seen one in a 78/7. Unless someone else put it there you will not find a thick metal base gasket either. Remove the head and replace the head gasket. Leaving the top and bottom mounting studs torqued risks warping the deck and breaking the torque even a few foot pounds will likely destroy what ever remains of the head gasket adhesion anyway. When replacing the head gasket, you'll find that the head gasket placed in one position will partly cover the push-rod tube holes in the cylinder deck. Flip it end for end and the holes line up... Pay full attention. Don't forget to install new O'rings on the two upper cylinder studs - on both sides and when you use sealant on the cylinder base, use such a small amount that you'll wonder why you bothered...because if you goop it up, what squeezes 'out' on assembly also squeezes 'in'. Oh, all you need to do to prepare the push rod tube seals is smear a little engine oil on the outside where they enter the block and the inside diameter so they move easy on the tubes during assembly.

You'll be fine with the process. No expensive tools and the parts are inexpensive. There is lots of on line help. The 78's are real easy to work on.
 
Na Cl K9 said:
I read the reply's and did not see anyone mention this:
Don't remove the piston from the cylinder. When the moment comes, pull the cylinder back from the block until you have exposed the piston pin. Your R80 will most likely have the style of pins that have groves for external snap rings that require snap ring pliers and are easy to remove and install. You can pull the wrist pin and remove the cylinder with the piston still in the bore. On assembly replace the old snap rings with new ones and pay attention to the rings edge. Keep the sharp edge away from the piston body when installing. the gap in the snap ring should go either up or down and should never be positioned in the direction of piston travel. If you find wire rings in groves in the piston remove them using a small pliers. Replace them with new as above. BMW sells a wire cir-clip I personally could not install. Way to stiff wire. Max sells the wire clips like the ones that BMW used in the earlier /5 /6 /7 and they are much easier to work with. These parts are one time use due to annealing of the spring steel during heat cycles.

By leaving the piston in the bore you eliminate the potential for breaking a ring, positioning the ring gaps wrong or scratching the cylinder and, with piston removed you would really need to rough the cylinder surface up as the rings will never go back the way they were which messes up your compression a bit. The chance of finding a big cylinder base O' ring installed in your bike is small. I've never seen one in a 78/7. Unless someone else put it there you will not find a thick metal base gasket either. Remove the head and replace the head gasket. Leaving the top and bottom mounting studs torqued risks warping the deck and breaking the torque even a few foot pounds will likely destroy what ever remains of the head gasket adhesion anyway. When replacing the head gasket, you'll find that the head gasket placed in one position will partly cover the push-rod tube holes in the cylinder deck. Flip it end for end and the holes line up... Pay full attention. Don't forget to install new O'rings on the two upper cylinder studs - on both sides and when you use sealant on the cylinder base, use such a small amount that you'll wonder why you bothered...because if you goop it up, what squeezes 'out' on assembly also squeezes 'in'. Oh, all you need to do to prepare the push rod tube seals is smear a little engine oil on the outside where they enter the block and the inside diameter so they move easy on the tubes during assembly.

You'll be fine with the process. No expensive tools and the parts are inexpensive. There is lots of on line help. The 78's are real easy to work on.
Click to expand...

Totally agree, as this is what I did on a recent 1979 push rod seal replacement. The longest wait time was waiting for parts!:violin
 
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