Push rod tube seals.

I have a 1993 R100R that I purchased used a couple of years ago. The bike sat in the previous owners garage for quite a few years without much riding. It only had 12,000 miles on it and looked like new. What a lucky find for me. The only problem I am having is it seems most of the seals are slowly getting replaced as they seem to have dried out due to the previous owners inactivity of riding. Now to the meet of the question. All four pushrod tube seals are leaking especially if the bike has been parked for a couple of days. I plan on replacing these myself and have never worked on this bike other than oil changes and valve settings. Is this an easy thing to do or should I take it to a shop? I've read the repair manuals I have and it looks like I can do this. I just don't want to take off the cylinder heads and then shout oh no

I haven't replaced the seals and haven't done much repair work on my bike other than what you have described. I need to replace mine and have decided to give it a try. Thought the post below might be of some encouragement to give it a try.

http://home.jps.net/~snowbum/pushrodseals.htm

good luck!

Those instructions make pushrod seals WAY more difficult than they really are. If you're only doing the seals, then don't screw around with the pistons at all.

1) Put motor on TDC.

2) Loosen exhaust nuts. You SHOULD borrow the RIGHT tool (at the dealer?) to crack them loose and then ride home to do the job. The biggest "gotcha" on this job is stuck exhaust nuts. (Another topic for another time.) Remove the exhaust nuts and yank the headers out of the jugs.

3) Remove carbs, spark plugs and valve covers.

4) Crack each of the four nuts that hold the rockers loose. Then remove them. Pay attention to what goes where and how they're positioned. Remove the rockers and the pushrods.

5) Pull the WHOLE JUG out from the bike about an inch and a half or so. Do NOT pull it any further if the piston so much as starts to come out the bottom.

6) Remove old PR seals. Take new seals and rub them with your hands until you remove any "skin" on them. MAYBE put a single drop of motor oil in your hand and rub it all over your fingers and then rub each seal with your fingers.

7) Install new seals. The line points toward the center of the Earth.

8) Reassemble in reverse order. Make SURE you get the rocker blocks TIGHT up against the rockers, but not so tight that the rockers are binding. Put some high temp anti-seize on the exhaust nuts and do NOT over-torque them.

9) Go ride.

*) Note: Depending on your airhead, you might have base gaskets or o-rings at the base of the top studs and/or an o-ring on the base of the cylinder. If you find you want or need to replace these, too, here's how to do it...

5) Yank the jug off the bike. Do not let the rod bang against the crankcase. Put a rag there.

6) Turn the jug upside down on the bench and replace the seals. Replace the o-ring (if there is one) on the base. Replace the base gasket (if there is one), probably still on the bike. Replace the o-rings (if they are there) on the top studs even if you pulled the old ones out of the bottom of the jug.

7) Get two reasonably large hose clamps and put them in a "69" position around the rings. You want the clamps tigh enough to compress the rings but loose enough to slide. Push the jug back on. Remove the "ring compressor."

8) (Continue with (8) above...

There is NO NEED to crack the head seal unless you WANT to. If you do... replace the head gasket. If you don't want to crack the head seal... just don't mess with the head nuts at the 12 and 6 o'clock positions.

Thanks for the information. I'm going to order the parts this weekend!

I just replaced my "push rod seals" a couple weeks ago.

Even tho it's a "No Brainer Job" things can still be ruined easily if care is not followed correctly.

When I pulled off the cylinder jugs,I also "de-carboned" the head and piston and checked the rings.

Remember to buy "new" head gaskets. There is also an "O-Ring that goes around the base of the cylinder jug. The factory uses a sealant during assembly, the O-Ring will not be found or present if the cylinders have never been removed.

Their is also 2 little O-Rings that should be replaced that are in the base of the "jug" that fit on the cylinder jug "studs".

You will definately need the "exhaust nut" removal tool,otherwise your gonna have big problems. If the nuts are "frozen" you run the risk of stripping the "threads" in the cylinder head,which means "$$$$$$", so "cut them off" with a hack saw if "tight".
Get the exhaust "do-nut" ring kit and aluminum sleeves for reassembly of the exhaust system, that way you don't have exhaust leaks after reassembly.

Remember to use plenty of "Never-Seize" when assembling the exhaust system back together. Helps with removal in the future.

Good luck and get a good "Repair Book" to help guide you along.

nvbird said:

Thanks for the information. I'm going to order the parts this weekend!

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I'd appreciate a debrief once you've replaced them.

You will definately need the "exhaust nut" removal tool,otherwise your gonna have big problems. If the nuts are "frozen" you run the risk of stripping the "threads" in the cylinder head,which means "$$$$$$", so "cut them off" with a hack saw if "tight".

Agreed.

Get the exhaust "do-nut" ring kit and aluminum sleeves for reassembly of the exhaust system, that way you don't have exhaust leaks after reassembly.

I don't know about this. My R80G/S came apart LOTS of times for various things and I NEVER used new exhaust gasket bits. I've never had a problem with the exhaust not sealing on dozens of /5, /6 and /7 airheads on which I've worked. Unless they changed the parts sometime between 1981 and 1993, the original exhaust split washers and sealing washers should do just fine.

Remember to use plenty of "Never-Seize" when assembling the exhaust system back together. Helps with removal in the future.

I use a copper-based hi-temp anti-seize compound with excellent results.

In the past I have switched back and forth between the copper and nickel Neva-Sleezze on my exhaust systems and actually have thought the silver goop worked better.
But , just recently I read that you are supposed to use the copper stuff on aluminum.
I break my exhaust nuts and relube at least once a year.



S

I break my exhaust nuts and relube at least once a year.

Excellant Idea!!!!!!!!!!!!!

On this GS100 I have, in order to change the "earl filter" you have to remove the exhaust pipe on the right side in order to remove the housing. The head exhaust nut/gasket is re-lubed each time the "earl filter" is changed.

Pardon my ignorance, but I have to change the seals on my r100s and was wondering if I need to drain the engine oil first.
thanks,

Nope, though you'll have a little dribble out when you pull the valve covers.

Pardon my ignorance, but I have to change the seals on my r100s and was wondering if I need to drain the engine oil first.

As long as nothing falls in the engine, as your working/ cleaning around it.

Nope, though you'll have a little dribble out when you pull the valve covers.

You got that right!!!!!!!!!

push rod tubes

Hey Wes you wanted to know how it went. Well it took me about 4 hours to replace my push rod tube seals. It went very easily. The hardest problem I had was finding top dead center for the engine. That was very hard to read. Someone, maybe the factory put a green dot that was suppose to be TDC. That helped. The o rings all looked good and I followed the steps that flash 412 put up on the net. Very easy. The only thing I noticed was that the ticking on the rockers seemed to be louder than before. I adjusted these to specs. I plan on giving it a good ride and then reset the valve gap again. Maybe its just my imagination. I bought new seals etc but everything looked so good I just didn't replace them. No leaks so far. Easier than I thought it would be. Russ

Russ,

Congratulations and thanks for the post!

Re: push rod tubes

nvbird said:

The only thing I noticed was that the ticking on the rockers seemed to be louder than before. I adjusted these to specs. I plan on giving it a good ride and then reset the valve gap again. Maybe its just my imagination. Russ

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I always rotate the engine through a full 360 Deg. then recheck clearance, I've found that sometimes I needed to make a minor adjustment after doing so. Saves having to open it again and redo. Esp. if the timing chain has some miles on it, say over 20-30K there can be a slight variation in valve timing due to slop in the chain.

Also could be due to the valves having been set to tight before, looser is better than tighter.

RM