Gasgas 300 Txt Pro Forkseals

[edholland]

Yes the black is magnetic but wow there is a lot of it ! i,m pretty sure this is the first oil change on mine. Will use brake cleaner to clean things up and i ordered new bushings it,s hard to see on the picture but there are some pretty big scrathes on both.

Waiting for parts now and need to get oil, i,m a beginner at trials what weight of oil should i get ?

Cheers,

[jse]

Yes the black is magnetic but wow there is a lot of it ! i,m pretty sure this is the first oil change on mine. Will use brake cleaner to clean things up and i ordered new bushings it,s hard to see on the picture but there are some pretty big scrathes on both.

Waiting for parts now and need to get oil, i,m a beginner at trials what weight of oil should i get ?

Cheers,

The Marzocchi forks take a slightly heavier oil than the GasGas forks due to the damping mechanism. 7.5 weight rather than 5 weight seems to work best overall. What's nice about that is that you can use Dexron III ATF, which is about 7.5 weight and has the right additives like an anti-foaming additive, and has good lubricity.

And while you're at it, pick up some Plumber's Grease from a hardware store (you'll only need a small container). Plumbers use it to lube o-rings and seals and is Silicone based (and inert), but it's real handy to lube seals/o-rings and safer than mineral based lubricants in certain places, like the servo cylinder "top hat" in the clutch sidecover.

Jon

Edited April 27, 2008 by JSE

[edholland]

Jon i think you have found a new way to get the seals out did the other one with just boiling hot water and they came out the first hard pull ! You were right about me damaging the bushing with trying to get them out on the first one. The bushings looked fine on this one.

Oh well i ordered new bushings for both and will keep the best as spares. Seals are in and the dustshields or on i used a plastic tube like the guy in the video showed works great to get the seals in there.

Now for filling them ?

Cheers,

[jse]

Jon i think you have found a new way to get the seals out did the other one with just boiling hot water and they came out the first hard pull ! You were right about me damaging the bushing with trying to get them out on the first one. The bushings looked fine on this one.

Oh well i ordered new bushings for both and will keep the best as spares. Seals are in and the dustshields or on i used a plastic tube like the guy in the video showed works great to get the seals in there.

Now for filling them ?

Cheers,

O.k., now for the fun part! You'll want the top cap off and the spring out to start with. Put about 100cc's of 7.5 weight oil in the tube to start with and with the top tube collapsed, reach inside and get hold of the damper rod (I use a special tool made for this but you can use a long neck pair of pliers-never quite sure why it is called a "pair" anyway) and slowly pull up to get the oil circulating in the cartridge. After you've done that a few times, add another 100cc's of oil and bleed the cartridge of air some more. Make sure you pull the rod all the way to the top of it's stroke and you'll start to feel consistancy in the resistance as the air comes out of the cartridge.

As they usually take about 290cc's total, add another, say 70cc's so it will be close to the required level and make sure there is no trapped air by stroking the cartridge some more just to be positive. You can make a tool to set the oil level using a turkey baster, thin straight metal tubing and some fuel line but you'll probably rarely use it, so the "quick and dirty way" is to take some thin rod, like welding rod, and put a zyptie on it 180mm from one end to use as a "dipstick" (the zyptie rests on the top of the tube). Then, by adding or subtracting oil from the fork and checking it with the rod to get 180mm's from the top of the tube, you can set the oil level (of course, cleaning the rod each time to get a good reading). adding 270cc's would probably work well for you as a start as it's a little easier to add oil than take it out. Remember, top tube collapsed and spring out to set oil level.

The oil level setting tool I would use is set for 180mm on the thin metal tube, the fork slightly overfilled, and the tube put inside the tube (dropping down to 180mm's from the top) and the syringe used to suck out the excess oil.

Jon

[edholland]

Thanks again Jon ! i found the Dexron III ATF here and will try to fill them tonight.

Cheers,

[jse]

Thanks again Jon ! i found the Dexron III ATF here and will try to fill them tonight.

Cheers,

Take your time and remember to pull the cartridge all the way up to the top of it's stroke (slowly or it can get messy) to bleed it of air. You'll "feel" when the cartridge is air-free, I can't really describe it, but you'll know what I mean when you do it. The rod will have resistance and then, all of a sudden, pull to the top without drag if air is still in the cartridge. It should have full, consistant resistance all the way to the top of the stroke.

Good luck.

Cheers.

Jon

[edholland]

Done i did a complete overhaul of the bike with help of this board. Big thanks go out to Jon and PeterB you guys are awesome !! i did all using the search button and your help with things i coulden,t find here. It,s fun to do it yourself and i learned a lot about how a trial is build doing the overhaul.

WARNING if you take out the seals with the boiling water method let them cool off first or use cloves ! i diden,t and had the GasGas logo burned in my right hand for a few hours

Thanks to all who posted their info here !

Cheers,

Ed

Edited May 8, 2008 by EdHolland