Forks leak when compressed, but not when upside down...

[Adi]

Has this happened to anyone before? I have 01 Z5s, and will be taking them down to my LBS in a day or two. Anyone know what can be done about this and what is at fault? They leak near the vee brake bosses.

Thanks in advance!

 

[andrew]

is the leak from the join of the leg and the arch ? if so rmove the oil in that leg. remove the brake boss (un screw with 9mm spanner i think) hold the leg tap the arch up with a mallet a bit to seperate. clean well with spirits .. and put some silicon around the arch(should have bushing in it still to stop silicon going inside leg) join them back together tighten the boss back up and leave to sit for 12hours go around the outside with a sharp knife to remove any silicon ... don't pull it or you'll reck the seal you just made then add new oil and you should be right.

or you could just let all the oil out and run them oil-less

 

[S.]

When you turn em upside down, all the oil is running into the uppers, which is why they don't leak (it's inside the inside leg sorta thing... not up against the seals so much). Your seals are blown tho, you're looking at about $50 + labour for a fork service, during which they'll replace the seals.

 

[Adi]

Okay, thanks for that

 

[belly_up]

the other thing is that when compressed the oil will be slightly pressurised, unlike when they are just sitting upside down, and this may be enough to force the oil past the seals.
Like socket said, probably new seals.

 

[schmook]

my 2 cents

i dont think its the seals that are farked because otherwise oil would come out when the forks are tipped upside down
rather before the bike was sold to ya, it was serviced and they were a bit over enthusiastic with putting oil in the forks. and when you compress them the excess oil has to go somewhere. so it comes out.
do the forks feel stiff?

 

[Ty]

socket is right, when the bike is upside down the oil drains into the stantions so there is no or little oil sitting on the seals, also when fock is "compressed" you are putting presure on the oil and it wants to go somewhere, out of the seals is the only way to go.

 

[Curly]

I have a pair of Z4 Flylight airs. They were replaced under warranty because they were leaking from the front of the lower legs - underneath one of the stickers! Probably halfway between the brake bosses and the dropouts.

Read that again.

There was a casting flaw that allowed a pinhole leak. Pretty scary how little material there is on the legs.

Warranty replacement set have been flawless ever since - great forks.

 

[Adi]

Yea, I took em down today, they said there gonna ring em up to see if they can get the parts down. Thanks for all the input again

 

[RaID]

or you could just let all the oil out and run them oil-less

believe or not i actually did that once (not on purpose) with old z1

besides not having any dampening
when the fork runs out of oil
put it this way, it just doesnt sound healthy to say the least
(let alone work)


regarding the question
yeh its just your seals are blown replace them
the other guys are right the oil is now inside the stantions

 

[andrew]

my air fork worked with pretty much no oil! it tops out to the fat, and has no damping but apart from that mine was fine

 

[wombat]

my air fork worked with pretty much no oil! it tops out to the fat, and has no damping but apart from that mine was fine

Emphasis on "WAS fine". It would probably be alright for a while, but one of the principal functions of the oil in a fork is to act as a lubricant. Running them dry is just going to kill all the parts where friction is present.

 

[andrew]

my air fork worked with pretty much no oil! it tops out to the fat, and has no damping but apart from that mine was fine

Emphasis on "WAS fine". It would probably be alright for a while, but one of the principal functions of the oil in a fork is to act as a lubricant. Running them dry is just going to kill all the parts where friction is present.

true. but they were goning to die some other way before they wore out. creased stantions now