Fibre washers

[AdrianS]

Does anyone else have trouble with getting new fibre washers to seal?
The new ones seem to be made of a much harder material than they used to be and just don't ( in my opinion) seal as well. I have slight weeps from my Bantam gearbox drain, B40, and A50 gearbox, despite fitting new washers and tightening correctly.
Think I may have to start using Dowty washers.

[robincroft]

Dowty, aluminium  or annealed copper washers are my preference. Fibre washers are in my experience often troublesome.

Robin

[Pete A10]

I think one of the problems is expectation. In the 60's and 70's when we used our bikes every day and they were covered in grime and we parked them on the street we didn't notice the odd drip of oil. The reputation that British bikes had for oil leaks was no accident - it was because they leaked oil!!! Nowadays we keep our polished classics in their heated garages and use them a few times a year when the sun is shining (apologies to those few souls who I know do use their bikes regularly and think of them as transport) and yet we expect the technology designed in the 40's and 50's to produce different results than it did in its heyday. Maybe I'm a bit masocistic but I find part of the attraction of old bikes is that they have their weak spots and are not soulless clones of one another like their modern day counterparts. On the other hand have you ever tried changing the spark plugs on a Triumph Explorer - I think Triumph start with the spark plugs and build the rest of the bike around them. Other thing to note is that the modern Triumphs use aluminium washers not fibre ones!!!

[Beesy]

If  there ain't no oil under it, there ain't no oil in it!

[B Murphy]

I stopped using fibre years ago, just use a copper washer that squeezes up and seals.

[AdrianS]

I still feel that the fibre washers from the 60's and 70's sealed better than the ones made today!

[DAVE BRADY]

Hi,

I think that lots of things are made differently today.  It would not surprise me if the old fibre washers had asbestos in them.  With regards to leaking BSAs, I remember the summer camp of 1996.  Held in Germany, it was on field that was part of a water catchment so no oil could be dropped on the ground.  Drip trays were issued to be put under all bikes.  After riding there and few runs out only one out of well over 50 bikes had oil in the drip tray.  This could be forgiven as it was a 'V' twin with a total loss oil system. 
I think with modern gasket material and superior sealant we stand a better chance today of having an oil tight BSA than those owners of the '50s and '60s, probably.

Dave.

[Beesy]

I agree with that Dave. The sealants are really better. Also owners are prepared to take the time and effort to clean and prepare everything to the minutest detail to achieve it.

[Mike Farmer]

 

Hi

That's a very valid point. "back then" when I was using a bike every day, there was often simply not the time to spend on it and if it dripped a bit, then it dripped a bit. "Oh bother??" its still dripping oil.

Now I have time to take a great deal more care and redo bits as I go along. I've just finished an A65 that I bought in Dec 2012, doing a bit here and a bit there so hopefully it doesn't develop a leak somewhen down the line. I hasten to add that I've been doing others as well so the time frame is not an indication of my level of idleness.

Take care
       
Mike

[Phil C]

Adrian comments that fibre washers seem to be made of a harder material than they used to be. Gaskets seem pretty hard to me. For example if you're tightening, say, a primary chaincase cover, you don't want to be tightening the Allen bolts very hard ( as discussed on this forum) and I wonder whether the gasket might be not forgiving enough. I wonder if they were always like that.   Phil

[DAVE BRADY]

Hi Phil,

Years ago gaskets were little more than brown paper or very thin card.  Today's ones may seem hard but when you take a cover off you can see where they have compressed.  They are also more able to compensate for slight defects in the joint surfaces. There is also the advance in material technology.

Dave.

[JulianS]

Not all fibre washers are the same - the materials vary from quite hard - like the ones used in the magneto points assembly - to much softer like the ones used on fork drain for example.

As well as aluminium Dowty and copper you could consider nylon washers.