small crack in case

[msd808]

today i was riding and my chain came off and got jammed up, the threads on the case got a small crack on both sides, i have a 2010 ec300 and its pretty new, so i dont want to buy the whole case side. my clutch lever was a little harder to pull to, could that be from dirt or oil leaking out of the slave, or is that from the small cracks on the case. the cracks are from the chain slave guard. I was wondering if i should jb weld the cracks, but i cant have my lever being hard, i need it as soft as possible. ive only had jap bikes with cable cords so am new to hydro. please help

[andoman]

Can you post some pix?
Out of curiosity, what made the chain come off?

If you are loosing fluid from the clutch, it shouldn't get hard, it should get spongy and not disengage the clutch completely.
If its binding, it could be that the slave was displaced slightly and that your bolts are bent. Take the bolts out and check. If they are bent, new bolts may re-align things and solve the problem.

JB weld is a great product and can permanently fix small cracks.

Welcome to the GG Rider's Club!

[msd808]

the cracks are about 1mm exactly aligned with the bolts in the slave gaurd, top right bolt hole has just a really small crack, so im scared to tighten too tight, i need to JB weld first, but no fluid is leaking out right now with everthing back together, but the clutch lever is kinda stiff, not rediculas but harder than it was. this all happened in the trail and the chain came off it got supe stuck, so had to remove the clutch slave, probably got some dirt or air in, would bleeding the clutch help, or would dirt or air make it squishy, cause its super snappy, just harder than normal. i can take a picture of the cracks tommorow morning, but they are exactly like you would imagine would crack when the chain throws hare. the chain came off cause it was too lose, i should have tightened it, thought no big deal, and it cracked cause those stupid clutch slave gaurds only brace it with the casting of my engine, no backup.

[andoman]

Could be dirt.
Pull it apart and make sure that everything is clean. Make sure the O-ring is not out of place. Make sure the bolts are not bent. Put it back together and tighten it up. Use a torque wrench to make sure that you don't over-torque things. Clean the cracks with acetone, then use the JB weld. If you use the JB without the stress of the bolt torque on it, the JB may crack when its stressed upon torquing things up.
Then completely back-bleed the system and see how it is.

[msd808]

when you say pull it apart, do you mean take the piston out of the slave cylinder to check the o-rings, or just look without pulling everything out the housing. i JB welded the crack today and its fine, the slave does leak a tiny bit of oil when everything is tight, but the clutch feels springy, maybe a little spongey. my chain did slam the slave housing pretty hard, could it have warped the whole housing. i have to get suringes on monday to bleed it. could i put gasket sealer under the slave cylinder where it is metal to metal or no. i changed out the 3 bolts with new ones incase they were bent. thanks for the help.

[msd808]

my bike is a 2010 gasgas ec300, it says mineral oil on the cap, can i use fork oil or not.

[andoman]

Yes, fork oil works fine. Not two heavy. I would use 5wt if you have it.

I thought you had it all apart in the field. My suggestion to check the o-ring fitment was made in the case that it may have gotten out of place upon reassembly. If you never had it apart, then the piston and o-ring are likely fine.
As for the spongy feel: its air in the system. That should firm up when you back bleed it.
Yes you can use a little form a gasket to help with your leak.

Am I to assume that the binding or stiffness you felt is now gone?

[msd808]

I just took the slave off in the trails, i didnt pop the spring and piston out at all, the chain was just jammed to hell, so i took the slave off, unjammed chain, and then put slave back on. I just got home from work, so i havent bleed the clutch yet. thanks for all the help and i will let you know if i get it fixed.

[msd808]

last night i back bleed the clutch and it was exactly the same when done, so i had an extra magura master cylinder with the midwest mountain engineering easy pull lever on it and replace the stock AJP master cylinder with it, luckily it just unscrewed on the top and screwed in the magura. its now a lot easier to pull than before but probably just because of the midwest lever. my AJP unit looked brand new, but the fluid resivoir does look kinda warped or something, just not perfect rectangle, is that how the AJP units are or could that be the reason for the hard pull of the lever, cause i seen the rebuild only comes with spring, rubber, ect... but anyway the magura master cylinder screwed right in to my hose and worked easy, so i guess im sticking with the magura setup for now, but i really like AJP when it was new.

[pscook]

Doesn't the AJP use Dot 4 brake fluid and the Magura use mineral oil? Those are two incompatible fluids, and the seals don't like the wrong fluid behind them. I don't know for sure, I just know that there may be a difference between AJP and Magura.