crossercrosser Posted August 12, 2008 Report Share Posted August 12, 2008 I am new to trials and am currently having problems bleeding my clutch. This was after I managed to crack the original silver magnesium clutch case. I bought a new black one from gasgas uk. The new one will only take the smaller narrow spring that sits in the clutch basket and not the larger one that was in the original clutch case, is this causing me any problems when trying to back bleed the clutch as I am having no success back bleeding it. I can get fluid all the way up the pipe until it spurts out the end, however, when I connect the pipe up to master cylinder nothing happens no fluid seems to flow into it. Please help. I have also contaminated the clutch plates with gear oil and hydraulic fluid, what is the best way to flush this out and what is the best oil to put back in. A hopeless trials mechanic. Quote Link to comment Share on other sites More sharing options...
jse Posted August 13, 2008 Report Share Posted August 13, 2008 I am new to trials and am currently having problems bleeding my clutch. This was after I managed to crack the original silver magnesium clutch case. I bought a new black one from gasgas uk. The new one will only take the smaller narrow spring that sits in the clutch basket and not the larger one that was in the original clutch case, is this causing me any problems when trying to back bleed the clutch as I am having no success back bleeding it. I can get fluid all the way up the pipe until it spurts out the end, however, when I connect the pipe up to master cylinder nothing happens no fluid seems to flow into it. Please help. I have also contaminated the clutch plates with gear oil and hydraulic fluid, what is the best way to flush this out and what is the best oil to put back in. A hopeless trials mechanic. I'm a little confused about what spring you are talking about and am guessing you mean the coned washer "Belville spring", but I'm not sure what that has to do with the clutch sidecover or do you mean the preload spring that pushes the servo cylinder out (it usually has an aluminum nail-like pin in the center)? The servo cylinder is that "top hat" looking thing that slides over the post on the inside of the clutch sidecover and presses on the "fingers" in the clutch assembly. As for the fluid not coming up to the reservoir, I think the adjustment screw on the lever is in too far and is closing off the bleed hole inside the reservoir. Back off the lever screw so that the master cylinder piston comes back to the stop at the circlip inside the rubber boot on the M/C. Brake cleaner usually will clean hydraulic fluid off the plates and don't worry about the gear oil, they run in a bath of it. If you have the newer, thinner, clutch Belville spring, you might want to try the Ford type-F ATF and change it every 5-10 hours of use. Cheers. Jon Quote Link to comment Share on other sites More sharing options...
peterb Posted August 13, 2008 Report Share Posted August 13, 2008 Hi crosser, If your bike is an 05 model, it will have a mineral oil clutch system, not hydraulic fluid. To check this, the clutch master cylinder cap should be green, if it is green (and for 05 it should be) then you have to use a mineral oil in the actuation system (I'm trying not to write - in the hydraulic line). If you have already mixed hydraulic fluid with the mineral oil in the clutch system, then you already have problems and need to replace the seals in the slave and master cylinders and flush out the clutch hose plus all wetted parts - I am not sure if you can just clean them up, you ever tried this Jon? The black clutch cover should have a spring and pusher post that resides inside the slave cylinder, the "top hat" shaped piston should fit over the two seals of the slave cylinder. These seals will be compatible with mineral oil only, not hydraulic fluid. Would be best to get a friend in your area to help you out with this one, ar at least an exploded diagram - check out the Gas Gas USA website for this - also the excellent repair video clips. Bye, PeterB. Quote Link to comment Share on other sites More sharing options...
copemech Posted August 13, 2008 Report Share Posted August 13, 2008 As Peter stated, you run into so big issues with seal / fluid compatability there. I have heard that you can get by with DOT 5 silecon based fluid in the '05 mineral oil system.whish may be true as the silecon based is fairly inert. Yet no dot 3 or 4 for sure. We have been told in a recent training class that there should be NO intermixing, period! Because of some wierd things happening between dots 3 and 4, and dot 5 was out of the question as far as compatability with the common fliuds. Turns to sludge or something! There should be no retro fitting between grades encouraged. One thing absolute, no mineral to dot 3-4! Willnnot work for long! Quote Link to comment Share on other sites More sharing options...
jse Posted August 13, 2008 Report Share Posted August 13, 2008 As Peter stated, you run into so big issues with seal / fluid compatability there. I have heard that you can get by with DOT 5 silecon based fluid in the '05 mineral oil system.whish may be true as the silecon based is fairly inert. Yet no dot 3 or 4 for sure.We have been told in a recent training class that there should be NO intermixing, period! Because of some wierd things happening between dots 3 and 4, and dot 5 was out of the question as far as compatability with the common fliuds. Turns to sludge or something! There should be no retro fitting between grades encouraged. One thing absolute, no mineral to dot 3-4! Willnnot work for long! Peter, The DOT-5 (Silicone based and generally quite inert) can be used in (as a total replacement) the DOT-3/4 or mineral oil systems and actually makes the lever about 20% smoother from our experience, but you can't convert between the DOT-3/4/5.1 and mineral oil systems without a total replacement of compatable seals/o-rings. I've always been suspicious of any intermixing and if the mineral oil system has DOT-3/4 in it, at all-even a couple drops, I'd replace all the seals. The DOT 3, 4, 5.1 (as I understand, DOT-5.1 is used in high-speed European ABS systems and appears to be a lower viscosity) is a very active solvent (and makes a good paint remover), and I've used it to soak carbon encrusted combustion chambers to make them easier to polish out. Some riders think that you can just drain the clutch fluid out at the bleed fitting and replace it with another type, but the whole system needs to be completely dis-assembled and throughly cleaned. I've converted all my clutch systems to DOT-5 and the seals and rubber boots last years without swelling. DOT-3, 4, 5.1__DOT-5__and mineral oil are not compatable with each other in clutch systems (Copey's correct and you'll usually end up with something that looks like science fiction sea monsters floating around in your fluid reservoir). Seals and o-rings made for mineral oil (often green in color) usually are damaged by DOT-3 type fluids, which are quite reactive. Jon Quote Link to comment Share on other sites More sharing options...
crossercrosser Posted August 14, 2008 Author Report Share Posted August 14, 2008 I'm a little confused about what spring you are talking about and am guessing you mean the coned washer "Belville spring", but I'm not sure what that has to do with the clutch sidecover or do you mean the preload spring that pushes the servo cylinder out (it usually has an aluminum nail-like pin in the center)? The servo cylinder is that "top hat" looking thing that slides over the post on the inside of the clutch sidecover and presses on the "fingers" in the clutch assembly.As for the fluid not coming up to the reservoir, I think the adjustment screw on the lever is in too far and is closing off the bleed hole inside the reservoir. Back off the lever screw so that the master cylinder piston comes back to the stop at the circlip inside the rubber boot on the M/C. Brake cleaner usually will clean hydraulic fluid off the plates and don't worry about the gear oil, they run in a bath of it. If you have the newer, thinner, clutch Belville spring, you might want to try the Ford type-F ATF and change it every 5-10 hours of use. Cheers. Jon Great thanks for your help. When I removed the original side case sitting inside the "servo cylinder" ( is this the same as a slave cylinder & clutch basket ) there were 2 springs, a small thin one sitting inside a larger one ,these 2 springs slid inside the post on the inside of the clutch side case. However, on the new side case gas gas sent me the larger spring is too big too fit inside the post. Another point is my reservior cap is black and it states " only use dot 4 brake fluid from a sealed container ". Thanks for all your help folks! Quote Link to comment Share on other sites More sharing options...
crossercrosser Posted August 14, 2008 Author Report Share Posted August 14, 2008 As Peter stated, you run into so big issues with seal / fluid compatability there. I have heard that you can get by with DOT 5 silecon based fluid in the '05 mineral oil system.whish may be true as the silecon based is fairly inert. Yet no dot 3 or 4 for sure.We have been told in a recent training class that there should be NO intermixing, period! Because of some wierd things happening between dots 3 and 4, and dot 5 was out of the question as far as compatability with the common fliuds. Turns to sludge or something! There should be no retro fitting between grades encouraged. One thing absolute, no mineral to dot 3-4! Willnnot work for long! Great thanks for your help. When I removed the original side case sitting inside the "servo cylinder" ( is this the same as a slave cylinder & clutch basket ) there were 2 springs, a small thin one sitting inside a larger one ,these 2 springs slid inside the post on the inside of the clutch side case. However, on the new side case gas gas sent me the larger spring is too big too fit inside the post. Another point is my reservior cap is black and it states " only use dot 4 brake fluid from a sealed container ". Thanks for all your help folks! Quote Link to comment Share on other sites More sharing options...
crossercrosser Posted August 14, 2008 Author Report Share Posted August 14, 2008 Hi crosser,If your bike is an 05 model, it will have a mineral oil clutch system, not hydraulic fluid. To check this, the clutch master cylinder cap should be green, if it is green (and for 05 it should be) then you have to use a mineral oil in the actuation system (I'm trying not to write - in the hydraulic line). If you have already mixed hydraulic fluid with the mineral oil in the clutch system, then you already have problems and need to replace the seals in the slave and master cylinders and flush out the clutch hose plus all wetted parts - I am not sure if you can just clean them up, you ever tried this Jon? The black clutch cover should have a spring and pusher post that resides inside the slave cylinder, the "top hat" shaped piston should fit over the two seals of the slave cylinder. These seals will be compatible with mineral oil only, not hydraulic fluid. Would be best to get a friend in your area to help you out with this one, ar at least an exploded diagram - check out the Gas Gas USA website for this - also the excellent repair video clips. Bye, PeterB. Great thanks for your help. When I removed the original side case sitting inside the "servo cylinder" ( is this the same as a slave cylinder & clutch basket ) there were 2 springs, a small thin one sitting inside a larger one ,these 2 springs slid inside the post on the inside of the clutch side case. However, on the new side case gas gas sent me the larger spring is too big too fit inside the post. Another point is my reservior cap is black and it states " only use dot 4 brake fluid from a sealed container ". Thanks for all your help folks! Quote Link to comment Share on other sites More sharing options...
jse Posted August 14, 2008 Report Share Posted August 14, 2008 Great thanks for your help. When I removed the original side case sitting inside the "servo cylinder" ( is this the same as a slave cylinder & clutch basket ) there were 2 springs, a small thin one sitting inside a larger one ,these 2 springs slid inside the post on the inside of the clutch side case. However, on the new side case gas gas sent me the larger spring is too big too fit inside the post. Another point is my reservior cap is black and it states " only use dot 4 brake fluid from a sealed container ".Thanks for all your help folks! "Servo cylinder" and "Slave cylinder" are the same, the former is a little more "politically correct" for various reasons, but also more technically accurate. The "clutch basket" is where the clutch plates reside and has a ring gear around the outside that meshes with the primary gear on the end of the crankshaft. Somebody thought it looked like a basket when upturned and since that's where you put all the clutch "stuff", I'm guessing that's how it got it's name. You might want to get the pin that fits inside the smaller servo cylinder spring you now have, it helps guide and stabilize the spring and adds a little more preload. Jon Quote Link to comment Share on other sites More sharing options...
copemech Posted August 15, 2008 Report Share Posted August 15, 2008 Maybe by the time you figure out which is the correct spring, pin, tophat and seals for your new case, you might opt for the newer lighter belville spring to finish off your frustration, since you are there? I don't know! Quote Link to comment Share on other sites More sharing options...
crossercrosser Posted August 15, 2008 Author Report Share Posted August 15, 2008 "Servo cylinder" and "Slave cylinder" are the same, the former is a little more "politically correct" for various reasons, but also more technically accurate.The "clutch basket" is where the clutch plates reside and has a ring gear around the outside that meshes with the primary gear on the end of the crankshaft. Somebody thought it looked like a basket when upturned and since that's where you put all the clutch "stuff", I'm guessing that's how it got it's name. You might want to get the pin that fits inside the smaller servo cylinder spring you now have, it helps guide and stabilize the spring and adds a little more preload. Jon Every day is a school day, thanks. I spoke to a great "techi" guy at Gas Gas and he tells me the same thing about requiring a pin for the spring. Quote Link to comment Share on other sites More sharing options...
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