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Gasgas 300 Txt Pro Forkseals


edholland
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doing an overhaul of the bike and it needs new seals on the front forks. Can someone tell me what parts i need to order please ? i hate to do just the seals to find out later some other parts should have been done at the same time.

Tia,

forkgasgas.jpg

Edited by EdHolland
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Ed

I've just changed a set of fork seals on a sherco and montesa and all I have had to do is the seals and oil,

my son's gasgas 80 is next but that will need the dust shields changing as well as they are cracking and letting

water sit between the seal and the shield...

Regards

Nick.

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Ed

I've just changed a set of fork seals on a sherco and montesa and all I have had to do is the seals and oil,

my son's gasgas 80 is next but that will need the dust shields changing as well as they are cracking and letting

water sit between the seal and the shield...

Regards

Nick.

Nick's right, you always want to check the wiper for cracks and also the bushings, but they rarely are worn on a bike as new as an 04'. From the diagram you give, you have the Marzocchi 40mm steel tube forks. The Marzocchis are a little different from the 38mm GasGas forks in that they take about 290cc's of fork oil, 5 weight if you like them "springy" and 7.5 (ATF works well for that weight) for "normal" performance, but the other difference is that the Zoke's cartridges usually do not fully bleed down when the forks are drained, so the best way to set them is by fork oil level, which is 180mm for the steel tubes (springs out, cartridge bled, fork compressed).

Jon

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Thanks Guys !

Jon i think i got it all but not sure about some parts. I will make some pictures and ask for your help if i may, this is this first time i,m doing forks so i might have some beginner questions :thumbup:

Cheers,

No problem, I'll help anyway I can. You can contact me through the GasGas USA or GasGas UK websites under "Tech", but you might want to ask your questions on this forum, there are a lot of smart people that participate here and a group focus works really well. I'm always learning new stuff on this site and some of the answers you get may help other riders also.

Cheers.

Jon

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I'm always learning new stuff on this site and some of the answers you get may help other riders also.

I agree that,s why i love forums ! i,m a long time member from a german car board just by using the search you can do a complete rebuild of your engine,gearbox,suspension with tips,pictures and tips from the professionals. Let,s make this a howto do seals thread maybe it will help newbies like me in the future :thumbup:

Cheers,

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Ok i got the interior out and the dustcap and snapring off. But i cant take the tube out ? on the gasgas video the guy pulls it out real easy with seal and all, tried a few hard pulls but no luck so far. Is there something else i should do first ?

Cheers,

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Ok i got the interior out and the dustcap and snapring off. But i cant take the tube out ? on the gasgas video the guy pulls it out real easy with seal and all, tried a few hard pulls but no luck so far. Is there something else i should do first ?

Cheers,

Sometimes they can be a little stubborn. In suspension work, a propane torch is real handy to heat the top part of the lower leg to break the bond the seal has developed (it also works on o-rings). The outside of the seal is designed to form a bond with the bore of the lower leg (like most seals) and a little heat really helps. I use the torch a LOT when doing suspension work. I know it seems like you're going to "break" something when snapping them apart, but that's the best way, just try to pull straight opposite from each other. I'm assuming you have taken the cartridge out by spinning off the "basebolt" at the very bottom of the lower leg?

Jon

ps. The guy in the video has made sure the seal is lubed and the legs pop apart easily before the camera rolls, nobody wants to look like a dufus on video (well, most of us....). :banana2:

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I'm assuming you have taken the cartridge out by spinning off the "basebolt" at the very bottom of the lower leg?

yes i did that :banana2:

The guy in the video has made sure the seal is lubed and the legs pop apart easily before the camera rolls, nobody wants to look like a dufus on video (well, most of us....).

i was thinking something like that must be it :rotfl: have a propane torch here will have a go with that.

thanks again Jon !

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Still no luck Jon how long should it be heated. I tried a few minutes i could smell the rubber burning but it doesen,t want to come out. Just to be sure i removed the basebolt and removed the top nut and removed the cartridge. After that i removed the dustshield and took the snapring off thats all i think ? On the picture are the parts i took off the shock.

shock.jpg

Edited by EdHolland
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Still no luck Jon how long should it be heated. I tried a few minutes i could smell the rubber burning but it doesen,t want to come out. Just to be sure i removed the basebolt and removed the top nut and removed the cartridge. After that i removed the dustshield and took the snapring off thats all i think ? On the picture are the parts i took off the shock.

shock.jpg

Now, that is a puzzlement. The upper tube is held in place inside the lowerleg by a combination of the cartridge and seal circlip (both you've obviously taken out). When you pull on the upper tube, the upper tube bushing contacts the washer under the seal and pulls it out. Sometimes the bushings contact and the "outer" bushings in the lower leg come out also, but rarely.

Rarely do you need to burn anything to get the seal out. Lets try something bizarre and boil some water and pour it all over the seal area (at a little over 200 degrees it shouldn't hurt anything), and about 6" away from the seal on the upper and lower part of the tube/leg area and then try snapping the tube apart.

Jon

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Ha the poor trick worked !!! got the first out and will do number two just doing the poor trick. I poored a liter boiling hot water over the seal and let it cool off. One hard pull and out it came :banana2:

Need to clean up things first and will post a picture of the bushings i think one needs to be replaced it looks damaged.

Thanks Jon !

Cheers,

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Ha the poor trick worked !!! got the first out and will do number two just doing the poor trick. I poored a liter boiling hot water over the seal and let it cool off. One hard pull and out it came :banana2:

Need to clean up things first and will post a picture of the bushings i think one needs to be replaced it looks damaged.

Thanks Jon !

Cheers,

Great!

Don't ask me where that idea came from, I was just trying to think of a safe way for you to heat the seal area and using a torch can be a little tricky as you need to know where to heat and how it will travel through the metal.

Take some photos of of the bushings, especially the inside if you can, and then we'll guide you through the installation process (and some tricks that will help and I'll probably learn a few from other contributers) and how to properly set the oil level in the Zoke's.

Cheers.

Jon

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shock2.jpg

Here is a picture of the bushings they both have the coating comming off. On one there is coating on the inside on the other the outside is coated. I must say the oil was really black en there was lots of sand in it ! what,s the best way to clean things out ?

Cheers,

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shock2.jpg

Here is a picture of the bushings they both have the coating comming off. On one there is coating on the inside on the other the outside is coated. I must say the oil was really black en there was lots of sand in it ! what,s the best way to clean things out ?

Cheers,

The one with the outer coating fits the upper tube and the inner coated one fits the fork leg. The frizted coating on the top part of the bushing was probably caused by contacting the washer when you tried to pull the fork apart. As long as the inner part has not worn through (the part that actually is the Teflon bearing surface) you may be able to get away with using them again as the coating is quite tough and rarely flakes off, or at least until you get a new set to replace them.

The "black oil" is caused by the outer part of the springs rubbing against the inner part of the upper tube (and the steel being worn off) and is "normal" but a good reason to keep fork oil fresh. The "sand", on the other hand, is not normal so I'd very carefully inspect the bushing Teflon surfaces for wear. You may be confusing "sand" with the small steel particles worn off the outer part of the springs that collect in the bottom of fork tubes (you could check what they are by using a magnet). Those particles can get in the damping shim stack (it's at the end of the rod that goes into the cartridge) and interfere with the operation of the damping.

I usually spray the inside of the tubes with brake cleaner to clean them out.

Jon

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