Fork Seals: Are OE or aftermarket better?

[Anonymous]

Getting ready to install 3rd set of fork seals on my 83 GS750ES. The originals lasted 7,700 miles, and the next 2 sets of Suzuki seals lasted only 12,000 miles each despite scrupulous cleaning of the sliders. Does anyone have an opinion as to whether aftermarket seals (e.g. Leak Proof) are more durable, or whether OE seals are better?

Simon Waters

[redliner1973]

Just curious, what weight of oil are you using in those forks? seals should last alot longer than that, unless thin (10W) oil, and minor scratches are on the sliders.

[daveo]

also curious as to whether that bike had anti-dive deleted?

[Hap Call]

Re: Fork Seals: Are OE or aftermarket better?

Getting ready to install 3rd set of fork seals on my 83 GS750ES. The originals lasted 7,700 miles, and the next 2 sets of Suzuki seals lasted only 12,000 miles each despite scrupulous cleaning of the sliders. Does anyone have an opinion as to whether aftermarket seals (e.g. Leak Proof) are more durable, or whether OE seals are better?

Simon Waters

I have seen some with a lifetime guarantee in Denis Kirk...try those.

Hap

[Anonymous]

Just curious, what weight of oil are you using in those forks? seals should last alot longer than that, unless thin (10W) oil, and minor scratches are on the sliders.

Using 15W oil (original spec is for 10W). Anti-dive has not been touched (i.e. still operational). Sliders appear to be in top shape. I have been wondering if very dry Colorado climate could be causing seals to dry out, particularly in 3-month winter mothball state. Also, I think I will try using lower air pressure in the forks (have been using 10 - 12 psi, may drop this to 3 psi) - wonder whether after-market fork springs would be a better way to firm up front suspension. Any opinions on that?

Simon

[daveo]

boy that doesn't seem right, I usually run 10-12 # air also, no prob, here's a thought before you change seals again, PJ-1 brand fork oil with 'seal sweller' I've always used this, haven't had a leak in 9 yrs,since I blew one inside-out, also adding 1/2 oz. or so of kerosene to fork oil will swell seal slightly, works on automatic auto trani's too.

[Billy Ricks]

PJ-1 fork oil has a seal swell additive in it. If you aren't already using it you might give it a try.

[robertbarr]

If you opt for Leak Proof, be sure that the 'backup washer' that they supply with each seal is large enough on the I.D. that it cannot contact the upper fork (slider).

They had the wrong washers included with their kits as recently as last year -- I got one such set, through Dennis Kirk.

Compare the kit's washer with the original. If the kit's washer is too small on its O.D, it'll be free to move too far laterally, and the I.D. can contact the upper fork.

[Anonymous]

after a spate of leaks I fitted double sided 37mmID/45mmOD off the shelf seals to my old girl and she has been fine. I use 15 grade oil with 15 psi.

[silverhorse47]

cause of failing seals

hmmmm...Colorado is dusty, right? perhaps...is it possible...that when you have rebuilt your forks in the past they have not been flushed, so that the seals are being eaten from the inside out?

And I don't agree that the higher pressures in the forks are 'ok'...wouldn't that air be applied directly to the bottom sealing lip o f the seal? The lip that seals the oil in? Which is different that the outer lip, which I think helps catch leaks and seal the dust out...

Also it is pretty hard to tell the condition of the sliding surface of the forks without disassembling them...there would be a problem down where you don't ever see the seal travel...

Sheesh...I sure hope this isn't nonsense...: )

Good luck.