Pushrod towers leaking

[Zombie Master]

1984 R100 70,000K Original owner

My left boot gets oil on it when first riding. Once I've ridden for a while it stops.

I've tried pushing them in the past and it helped a bit.

Can anybody suggest a tool for this?

Engine has never been apart and runs well, holds valve lash.

I've had replacement seals for at least a decade In stock, would they still be good? Not sure if they are OEM.

Any thought on treating engine oil with AT205 re-seal.

Thanx!

[Kurt in S.A.]

Exactly where does the leak come from? Hopefully it's not the oil pressure switch. From what I can tell, the collars on the tubes that push on the seals are brazed to the tube... (say post 1981). Using anything to push the collar tighter like begins to pull the tube out of the head...could create another problem.

I wouldn't use seals that old...I'd prefer to get new ones if needed.

Kurt

[Zombie Master]

How would I know how old the new seals are? Best from a OEM dealer?

[Kurt in S.A.]

I thought you mentioned that they were at least 10 years old. The seals are supposed to be squeezed against the engine. If they've lost their elasticity, they'll crack and you're back where you started. Maybe the cost of the seals is prohibitive??

Kurt

[Rob Frankham]

You need to find where the oil is coming from... there are various possibilities up to and including rust holes in the tubes themselves... that being said, the likelihood is that the seals at the crankcase end have hardened and started to deform. It's amazing that they have lasted tor 40 odd years without leaking before.

If the issue is minor, you can get away tapping the tubes gently out of the barrel. There is a tool designed for the earlier models, which had free moving collars to compress the seals, and this can be used to knock the later tubes with the brazed collars slightly towards the block. They are deeply seated and it's unlikely to cause any ill effects. This is really only a temporary fix though and, sooner or later, it will recur.

The next fix is to pulled the barrels away from the block and apply a non setting sealant to the joint faces between the seal and the block and between the seal and the tube. This can be done without removing the barrels completely as long as the rubber sealing rings between the barrels themselves and the block are in good condition... although you do, of course, have to dismantle the valve gear and remover the heads.

The best solution is to replace the seals completely... Your seals, if they have been stored well (out of sunlight and extremes of temperature) should be OK but the things aren't expensive and I think I'd go for new. Most of the ones you get from parts dealers aren't OEM but they seem to do the job. I normally put a smear of sealant on anyway for good measure.

Rob

[gspd]

Pushrod seals never leak onto boots, they just let oil trickle down to the bottom of the engine.
Are you sure that's where your leak is?

Valve cover and head gaskets often do leak onto boots.
Sometimes the actual tube pressed into the cylinder can leak, good time to replace with stainless.
There's also another shorter almost invisible tube pressed into the head that can leak, but that's very, very rare.

Regardless, after 40 years, a complete top end re-seal is on the agenda...base o-rings, head gaskets, P/R seals.
Easy-peasy.
Under $100 for parts https://www.euromotoelectrics.com/produ ... ndah-2.htm
The hardest part of the job is removing old the exhaust and re-installing it (with no leaks).
The only 'special' tool you'll need is for exhaust flange removal.

PS -
I never use any type of sealer anywhere on these top ends.
That's how the factory originally did it.
I know this from often having been the first one to disassemble many factory original top ends.
Never a mess of old sealer from the last guy to clean up.

[Zombie Master]

Thanx guys! I guess I'll do a refresh on the top end this winter. It's never been touched, so It should come apart easily. I'll go through all my parts stash and see if the tower seals are still supple. I guess there is no way of knowing how long new seals have been stored anyway.

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[gspd]

I guess I'll do a refresh on the top end this winter.

In the mean time...
Roll a piece of paper towel into a 4 inch long by 3/4 inch diameter 'cigar' and tightly pack it in (from underneath) between the main frame and the engine case, just below the pushrods seals. This costs nothing and can easily be replaced once saturated. It won't fix anything but It'll keep things clean by containing the leak until 'next winter'. It will be invisible even to knowledgeable spectators and admirers. A tampon might work just as well, but something about the string irks me.

PS - You're bike looks effin' great without that dog ugly tank cover. Aren't you worried that your heirs won't want it after you croak, now that it's been exposed to UV rays?

[SteveD]

It's a beautiful bike ZM. Good to see you're stilling using it.

The last time my left boot had oil spraying onto it, the oil pressure switch was the culprit. Messy, but a cheap and fast fix. An oil switch leak isn't likely to stop when warm though. I topped up 200ml after 200km! (100+100)

My left boot gets oil on it when first riding. Once I've ridden for a while it stops.

Looks like a bit of work in our future!