admacp Posted December 3, 2005 Report Share Posted December 3, 2005 My mates 03 gas gas 250 is having random clutch troubles. The clutch works fine on first use but doeas not work at all if it is "pumped up" a couple of times as you would normally use it in a section. There is always pressure at the lever and doesn't feel different during use. It works fine one minute and then not at all - the bike just keeps going with the clutch in. To date we have bled the system at least 4 different times (new Dot 4 fluid), fitted new seals inside the casing & fitted new clutch plates. Anybody had any experience of this or got any ideas how to fix this random fault? Quote Link to comment Share on other sites More sharing options...
gasgas Posted December 3, 2005 Report Share Posted December 3, 2005 Uhm, since you put in new slave-piston seals and the problem is still there i wld say pressure leak is at the lever side. Maybe seals are neccessary there also. You say you don't feel a pressure loss, but when you pull in the lever how long will it take before pressure is gone, hence bike is creeping forward? Quote Link to comment Share on other sites More sharing options...
agiow Posted December 3, 2005 Report Share Posted December 3, 2005 firstly when you fitted the new clutch plates did you measure the overall thickness of the three friction plates and 2 steel plates together. the dimension of the five plates together should be between 9.7 & 9.9 mm you can buy different thickness steel plates ie 1.3 or 1.5 & 2mm why are you using DOT 4 fluid ? has the clutch reservoir got a dark green cap which say's use mineral oil only if it has, and you use DOT 4 fluid it will eat your new seals finally after you bleed the clutch make sure you have about 1mm of free play at the clutch lever. Quote Link to comment Share on other sites More sharing options...
admacp Posted December 3, 2005 Author Report Share Posted December 3, 2005 The new clutch was ordered as a sealed pack and included the steel plates and the fibre plates. We tried putting the old clutch back in and it was slightly better but not much. We also tried various podsitions of the lever "play" and the best was to have the adjuster on the lever screwed almost in to a point where the lever couldn't even touch the handlebar grip (didn't slip even when that far in?). We are pretty sure that it requires Dot 4 fluid as my own 04 bike has Dot 4 mentioned on the reservoir (his 03 doesn't say anything). Quote Link to comment Share on other sites More sharing options...
admacp Posted December 4, 2005 Author Report Share Posted December 4, 2005 Nope! Been meticulous with all the parts (followed the parts book assembly!) Quote Link to comment Share on other sites More sharing options...
cdn280 Posted December 4, 2005 Report Share Posted December 4, 2005 Are you bleeding from the bottom with a syringe at the banjo bolt? Slow and steady is needed on these tiny hydraulic systems, and tap the lines as you do it to unstick any bubbles. Quote Link to comment Share on other sites More sharing options...
north_yorkshire_lad Posted December 5, 2005 Report Share Posted December 5, 2005 if you live in the UK send it back to shirty jr. if not send it to your nearest dealer/importer Quote Link to comment Share on other sites More sharing options...
lowbrow Posted December 6, 2005 Report Share Posted December 6, 2005 Hi, Inside the slave cylinder piston there is a spring and inside that spring there is a guide pin. If that pin is put in the wrong way round it can prevent fluid returning when the clutch lever is released. Maybe this is your problem? Good luck! Quote Link to comment Share on other sites More sharing options...
jtt Posted December 13, 2005 Report Share Posted December 13, 2005 admacp, are you saying the clutch drags, then if you shut the bike down and let it sit it comes back? I'm thinking it's something with the slave seals or the master cylinder seals. Did you put a touch of silicone grease on the new orings when you replaced them on the slave? As you may already know, it's also critical to be surgically clean during the replacement of these seals. Any contamination will cause these orings to fail prematurely. Also when bleeding the line, I've found it useful to use the syringe method that cnd280 combined with the traditional bleed through the slave. I've even used the syringe to draw fluid back through the slave. This back and forth motion will often break loose stubborn air bubbles. Quote Link to comment Share on other sites More sharing options...
admacp Posted December 13, 2005 Author Report Share Posted December 13, 2005 The clutch works perfectly the first time you use it from cold and also if it is left even for a few minutes. It doesn't work at all (no difference in feel on the clutch lever) after it's first use (i.e if you stop at a section and pull the clutch in all is fine. If you use the clutch a second time or more in the section then the clutch doesn't work at all - the bike keeps going!!!) Leave it a minute or two and the same scenario happens. We have tried new fluid, bled it loads of times, tried a complete new clutch and replaced the seals in the clutch casing. The only thing we haven't tried is the seals in the master cylinder - that is probably our last hope! Quote Link to comment Share on other sites More sharing options...
jtt Posted December 13, 2005 Report Share Posted December 13, 2005 The clutch works perfectly the first time you use it from cold and also if it is left even for a few minutes. It doesn't work at all (no difference in feel on the clutch lever) after it's first use (i.e if you stop at a section and pull the clutch in all is fine. If you use the clutch a second time or more in the section then the clutch doesn't work at all - the bike keeps going!!!) Leave it a minute or two and the same scenario happens.We have tried new fluid, bled it loads of times, tried a complete new clutch and replaced the seals in the clutch casing. The only thing we haven't tried is the seals in the master cylinder - that is probably our last hope! <{POST_SNAPBACK}> Must say I haven't come across this problem. I'd try the mastercylinder seals. Quote Link to comment Share on other sites More sharing options...
mintsauce Posted December 17, 2005 Report Share Posted December 17, 2005 i had a similar problem on my 04 280 It was cured by spening a long time tapping the hydraulic line from the engine up to the master cylinder whilst slowly pumping the lever until all the bubbles stopped. Quote Link to comment Share on other sites More sharing options...
crashmctavish Posted December 25, 2005 Report Share Posted December 25, 2005 They all do it! Try changing the gearbox oil to a 5w 40 as opposed to 10/40 change the oil regulally. the petals stick on the dowel posts usually when the bike is hot. Dont over adjust the master cylinder you must have some slack. check the tech section of gasgas.com it covers clutch set up. finally be sure there is no build up of metallic sludge just in the belville spring ring. I bleed the system using a 4ft long tube straight back into the master cylinder. Cheers Quote Link to comment Share on other sites More sharing options...
mad_ max Posted December 27, 2005 Report Share Posted December 27, 2005 shot it into the highest gear, hold clutch in and roll it backwards and forwards Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.