Still leaking forks

[GS1100Norway]

Hi all

No I`m a litle bit frustrated, I`ve changed the seals in the forks, but they are still leaking.
I`ve looking for scratches and other marks, but I can`t find any.
Do the air pressure in the forks have anything to do with this or...

I`m tired of this black oil rings on the fork legs, so are there anyone that can give me a helpful triks.... ?

Best Reg.
KnutK

 

[Bolder Biker]

Excessive air pressure can cause fork seals to leak prematurely. What fork pressure are you using?

I suspect, however, that the problem lies in:

1. Wrong fork seals used

or

2. Fork seals installed incorrectly (e.g. upside-dowm)

or

3. Too much fork oil added during seal replacement

or

4. You do have pitting and/or grooves in the forks' chromed surfaces which you haven't noticed.

BB

 

[GS1100Norway]

Thank you for your feedback BB.
The pressure in the forks has never exided 1.5kg pr.cm2, and the seals are monted the right way, so I may try another supplyer for possible correct seals.

Best Reg.
KnutK

 

[focus frenzy]

1.5kg per cm2 = 21.335 PSI for any one interested.

 

[Bolder Biker]

1.5kg per cm2 = 21.335 PSI for any one interested.

Although I seem to recall that maximum permissible pressure is about 35 psi, I think 21+ psi is a bit high for long fork seal life. I would be tempted to drop it to 10 or 15 psi (or whatever the kg per cm2 equivalent is). On my 1983 GS750, I have replaced the original fork springs with Progressive Springs (appropriately preloaded by spacers and using a slightly higher fork oil weight), and run the air pressure at 0 psi. My subjective opinion is that this setup is an improvement for my bike.

BB

 

[SqDancerLynn1]

The best seals are the OEM Suzuki

 

[saaz]

That pressure seems way too high. I run 10 psi or 13 if I want the suspension firmer. Make sure the oil level is as per specs, don't just go by oil volume. New seals sometimes take a little while to clear the oil used in assembling the new seals.

 

[KEITH KRAUSE]

I would'nt set the pressure at 21 psi either, that will just wear out the seals faster. Before I changed to Progressive springs I set the pressure around 10-12 psi.

 

[GS1100Norway]

Thank you all for your information.
I`ll try to go up a oil-grade or two, before I shange the seals to a another quality, and set air pressure to 0 PSI.

Best Reg.
KnutK

 

[sharpy]

oil leak

oil leak

When you replace the seals try "honing" the stanchion tubes with 600 wet & dry sand paper coated in WD40 using a lathe spun at low speed or with out sounding rude just some hand action. :roll:

 

[Bolder Biker]

Re: oil leak

Re: oil leak

When you replace the seals try "honing" the stanchion tubes with 600 wet & dry sand paper coated in WD40 using a lathe spun at low speed or with out sounding rude just some hand action. :roll:

Good idea!

When I was installing my1983 GS750ES's 3rd set of replacement seals (the dealer had fitted the first two sets in the bike's 33,000-mile life) I took a close look at the chromed surfaces. I found that the fork leg that had been leaking had two long grooves in the chrome surface on the back side of the fork, where I couldn't see them. I started smoothing them out with #250 or #350 "wet&dry", worked through #600, and finished with #1200. So far, no more leaks.

FYI, four more points:

1. I replaces the upper and lower (outer and inner) teflon-coated, "anti-friction" bushings and the dust covers while I had the forks apart.

2. When I compared the OE and Progressive Springs springs I found that both were "progressive", with two spring rates or coil pitches. The initial rate on the Progressives was much stiffer than on the OE's, although the final rate looked similar. The stiffer initial rate has largely got rid of that annoying pitch or dive when first applying the brakes. I increased the fork oil weight from the standard, Suzuki-recommended 10 weight to a high quality, 15 weight oil.

3. While I had the forks disassembled, I gave all the parts, including the fork's internals a good clean with kerosene. When refilling the forks (fully compressed and springs removed), I very carefully made sure that I had the forks filled to the correct level, and that both forks were equal in level. Grossly over-filling the forks can hydraulically lock them and lead to excessive pressure on the seals (like having way too much air pressure).

4. Keep the chromed fork surfaces clean. Even the hard, dried-up bodies of little insects can wear away at the rubber seals. It is amazing how doing a "fork job" yourself can motivate you to give the fork's sliding surfaces a little wipe after every ride.

BB