Bombers leaking oil -- Cause for concern???

[JohnH]

Yesterday I noticed that there was a little collection of oil around the seal at the top of the left stanchion on my Bomber Z2s. I wiped it off with some paper towel, but after riding the bike yesterday (and collecting some mud!), the oil is back...

The dry side (right-hand)...

And the oily side (left-hand)...

I've only just noticed that enough oil has leaked to leave a trail down the stanchion to the disc brake adapter...

Should I be worried?
Does anything need fixing?
Will my LBS be able to sort this out?

 

[FMJ]

I'd be worried if my fork was leaking, especially on the disc side. Fork seals on Bombers are easy to replace. There's manuals on Marazocchi's site that have a walk through.

 

[mechagouki]

Based on numerous encounters I'd have to say "it's a Bomber, ergo, it leaks oil". But as FMJ said, bomber seals are easy to come by (those forks didn't change much over a 10 year period), and changing them is pretty straightforward, though if you don't fancy trying it yourself, a bike shop shouldn't charge you much.

 

[JohnH]

Thanks for the replies, guys. I've had a look around and sure enough Bomber seals are available...

http://www.chainreactioncycles.com/Mode ... odelID=137
http://www.edinburghbicycle.com/ebwPNLq ... uctID=8493

...but it looks as though I'll need to ascertain whether my forks need 30mm or 32mm seals.

I'll also give my LBS a call tomorrow, just to see how much they would charge to save me the hassle.

 

[FluffyChicken]

Oil would only normally get out if the oil seal is contaminated and then worn.
If it's just started it could just be dirt has got it.
Pull them apart stanchion out (buy some more oil & fork grease) and clean them up. Don't do the seals just yet.
See if they work now, it shouldn't take to long and is a good practice.
Have a nosey at the bushings while you're there.
Also check the stanchion (dark gold bit btw) for scratches

If they are still off, then rebuild them..


What model are they anyway ?

 

[TheBowelsOfLove]

You need the seals for the 30mm stanchions of your Z2, same as my Z1 of that vintage, AFAIK. ?

 

[JohnH]

Oil would only normally get out if the oil seal is contaminated and then worn.
If it's just started it could just be dirt has got it.

Thanks for replying, FC. If you take a look at the seal on the left-hand side (third photo), you can clearly see a small gap between the seal and the stanchion, whereas on the right-hand side (second photo) the seal is tight to the stanchion. That's got to be a helpful clue for diagnosis.

Pull them apart stanchion out (buy some more oil & fork grease) and clean them up. Don't do the seals just yet.
See if they work now, it shouldn't take to long and is a good practice.
Have a nosey at the bushings while you're there.

I'll have to find one of those manuals that FMJ referred to and work out if I've got the right tools...

Also check the stanchion (dark gold bit btw) for scratches

There aren't any scratches. They're in perfect condition.

What model are they anyway ?

They're Bomber Z2 forks from 1995. There are clearer pictures of them here...
http://www.retrobike.co.uk/forum/viewto ... 7&start=23

You need the seals for the 30mm stanchions of your Z2, same as my Z1 of that vintage, AFAIK.

Thank you TBOL! The Z1s do look very similar to my forks.

 

[FluffyChicken]

1995, they are certainly 30mm then, (also there is a 30 on the seal)
Though I think 1997 is the first year of the bomber ?

The seals you se are just dust/sirt wiper seals, nothign else.
Under that there is another one, and it's the main oil seal that is the one too look at.
All you do is pull the legs apart. give it a wipe and clean then do the oil.
It might waste some oil but saves the pennies on seals if anything else is wrong.

Manuals here
http://www.marzocchi.com/Template/listM ... K&idC=1592
or here
http://my-sport.spb.ru/manual_1/index-16.htm
I think all these 30mm bombers are similar seal/bushing setup so look at the x-fly and the one above it for how to remove seals here
http://www.enduroforkseals.com/id10.html
and general tips.
Actual fork other bits will probably vary

Stanchion scratches- I was meaning bits inside the fork you cannot see, probably isn't but taking them part is a good check before the expense of a shop doing a full rebuild for you.

 

[drystonepaul]

Completely agree with Fluffy on this. Take them apart clean everything, replace oil and then try again.

I've had oil seals blow through due to slightly over filling with oil once before. The oil seal was undamaged and just required the above process to sort them out.

To further save money, don't buy the Marzocchi branded oil. Instead go to a motorcycle shop and get some good quality 7.5wt fork oil. (I use Silkolene Pro RSF) For the same price or less you'll get enough oil to do at least ten oil changes.

If they do still leak then it's time to order the oil and dust seal kit. And while you've got the oil seals out, it's well worth putting in some new bushes too.

 

[JohnH]

Cheers for those replies, fellas.

It's a bit difficult for me to do any bike maintenance at home: the house I rent has no garage or shed. The bike lives in the utility room with the freezer and the washing machine (I'd like to own a couple more bikes, but the complete lack of space prohibits it).

So I've just called my LBS: the seal kit costs £21.95 and the workshop cost to replace them is £25.

But after reading the advice from FC and DSP, I'm worried that the seals might not actually be the problem and replacing them won't make any difference...

Okay, I think I'll take the bike in and see how much an oil change costs...