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Whats Wrong With My Clutch?


redneck
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my bike has been stored for almost a year and in november i finally got the rear tire fixed, not as id like it though, and i hopped on to see if all was good and the clutch was beyond horrible. i let out all the adjustment then bled it twice. it is barley better now. now all the adjustment is taken up and the master cylinder (its an AJP) hits the stop point and at that point the clutch is disengaged just enough to come to a stop with out killing it. the running is very bad and is almost as if i had the clutch out.

how can this be fixed? should i bleed it from the reservoir to the ram where i was bleeding it from the ram up with a syringe? do i need a new master cylinder ( it does become wet around the ram )? are there rebuild kits for AJP master cylinders?

thanks in advance.

Edited by redneck
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hi when my bike was stored for a while 1st time i kicked her up, put in to gear i nearly went through patio window. i rang my bike shop and they said it may just be sticky plates. answer use the clutch as normal change gear through the box sounds painfull with no clutch but when you have been through the box my cluch released and went back to normal... just do it were you got plenty of space... ha

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i got it going thinking that the plates were just stuck but i dont think thats the case. i usually hold the rear brake when i put it in to gear first time after firing it up. that didnt help either. it just went through the brake and make a small pit in the dirt floor in my barn B) . really have to hold the brake if the clutch is back to the adjustment it was at originally. i have zoomed through my meadow to get through the box but nothing substantial. did ease up a tad bit not like it was about a year ago. ill try going through the box w/o the clutch after i do the brake hold method if it hasnt been fixed magically from my last ride a month ago. weirder things have happened. i plan to try to get out an ride after school today so i hope that it wont go in to gear because my clutch is that far adjusted. :thumbup:

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the lever feels normal, a tad spongy as of last night so i think a bleed is in store when my dad gets back from Cali. it drags enormously but there is still a hint of the fact the clutch does something like being able to stop and have the bike still running, yes a bit of throttle is added though.

again the lever feels normal, but a tad spongy but since all the adjustment is used it hits the stop point in the master cylinder.

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the lever feels normal, a tad spongy as of last night so i think a bleed is in store when my dad gets back from Cali. it drags enormously but there is still a hint of the fact the clutch does something like being able to stop and have the bike still running, yes a bit of throttle is added though.

again the lever feels normal, but a tad spongy but since all the adjustment is used it hits the stop point in the master cylinder.

If the M/cyl is leaking fluid where the adjuster attaches from the lever you will have to change the Seal, a seal kit is about

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Does it even have enough fluid?

And you cannot really just keep adjusting the screw on the lever you see, because the lever piston will not return enough to pick up new fluid.

Thete should be a little slack, or take it to zero. That is all, as it cannot push any more fluid than that! Yet if overadjusted, cannot return fully to allow more fluid in, you see.

If the fluid is low, you may have a leak into the gearbox section as well due to the seals in the case cover. And there are other possibilities with the clutch plates themselves i think. Specially as the bike has sat so long.

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again the lever feels normal, but a tad spongy but since all the adjustment is used it hits the stop point in the master cylinder.

I'm with Copey on this. The "all the adjustment is used it hits the stop point in the master cylinder " comment makes me think that you are possibly adjusting the screw on the lever in too far, which will have the opposite results you want.

You may want to take the lever off and pull the rubber boot on the master cylinder back to see if the piston is returning back fully to the stop at the circlip (sometimes the piston return spring breaks). Also check that the holes in the bottom of the reservoir are clear so fluid can be fed to the master cylinder bore.

Jon

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under the boot is a bit wet and i was thinking that was a problem, i have been like that for a while. where do you get the rebuilds or can i just go to the local hardware shop and get some o-rings?

ill try the adjustment as well, will bleed it first though if i can. last time i played around with the adjustment it didnt do much. the reservoir was full last time i took the cover off but i was getting massive bubbles when it was being bled a month ago.

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I'm with Copey on this. The "all the adjustment is used it hits the stop point in the master cylinder " comment makes me think that you are possibly adjusting the screw on the lever in too far, which will have the opposite results you want.

You may want to take the lever off and pull the rubber boot on the master cylinder back to see if the piston is returning back fully to the stop at the circlip (sometimes the piston return spring breaks). Also check that the holes in the bottom of the reservoir are clear so fluid can be fed to the master cylinder bore.

Jon

Jon and Cope may both be right.

If you don't let the piston retract fully it won't open the compensation port or the "By-pass port" as they call it here in this picture. Generically this is pretty much how your ajp looks inside too (except for one port instead of two shown here). Here's a tip. With the cap off you should get a squirt out of this port when you pull the lever. If you don't then the piston is in too far in and the piston is not pulling far enough back to get to this port open.

Flathead_Brakes_mastercyl_1939-40.jpg

Yes there are rebuilds out there for this that come with a new piston orings and spring. I wouldn't get orings from the hardware because these are specific for brake fluid and larger than what is needed orings will cause it to stick in the bore. The cir-clip can rust at the end under the boot and cause the piston to stick in the bore too.

--Biff

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Jon and Cope may both be right.

If you don't let the piston retract fully it won't open the compensation port or the "By-pass port" as they call it here in this picture. Generically this is pretty much how your ajp looks inside too (except for one port instead of two shown here). Here's a tip. With the cap off you should get a squirt out of this port when you pull the lever. If you don't then the piston is in too far in and the piston is not pulling far enough back to get to this port open.

Yes there are rebuilds out there for this that come with a new piston orings and spring. I wouldn't get orings from the hardware because these are specific for brake fluid and larger than what is needed orings will cause it to stick in the bore. The cir-clip can rust at the end under the boot and cause the piston to stick in the bore too.

--Biff

"Jon and Cope may both be right."

Biff, don't tell Copey that, I'll never hear the end of it! :wub:

I agree with Biff, the best way is to get a rebuild kit and hardware store o-rings will not work (incorrect size and material) as it's most likely a combination of the rear piston o-ring (which is causing the wet appearance under the boot) and special seal at the front (which is probably causing the lack of pressure). Rarely, it's is a broken piston return spring in front of the seal (a common problem in the early 90's AJP M/C's, but not now) which will not push the piston back to it's stop at the circlip and allow the system to equalize.

Jon

ps. Biff, it's 23 degrees outside down here in NE OK. now, which I imagine would seem like a heat wave to you guys up there......

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Jon and Cope may both be right.

If you don't let the piston retract fully it won't open the compensation port or the "By-pass port" as they call it here in this picture. Generically this is pretty much how your ajp looks inside too (except for one port instead of two shown here). Here's a tip. With the cap off you should get a squirt out of this port when you pull the lever. If you don't then the piston is in too far in and the piston is not pulling far enough back to get to this port open.

Flathead_Brakes_mastercyl_1939-40.jpg

Yes there are rebuilds out there for this that come with a new piston orings and spring. I wouldn't get orings from the hardware because these are specific for brake fluid and larger than what is needed orings will cause it to stick in the bore. The cir-clip can rust at the end under the boot and cause the piston to stick in the bore too.

--Biff

that image is just what i needed. Thanks! i will let out the adjustment and check for that squirt of fluid. i will also bleed since my dad is back home maybe he can help with that. well just have to see if its good after that. i meant by hardware store o-rings was just getting an DOT safe o-ring of the correct size and sticking it in there to replace bad ones instead of buying the whole kit springs and all which i may or may not need.

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Not 100% sure, but the seals in every master cylinder i have ever seen are lip type seals, not O rings.

I agree with the other guys about the adjustment, back it off and bleed the system. A trick i use on brakes is after bleeding the system, tie the lever back to the bar and leave over night. This allows any air to rise up the pipe and out the top of the resivour. Should work on the clutch.

A link i lifted from another post http://www.jkhirst.co.uk/acatalog/Brake_Levers.html shows the type of seals fitted.

Edited by passenger
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Gday - you need to check if your clutch is a brake fluid type or a hydraulic fluid type. The Hydraulic type has a green cap on the m/cylinder and uses a different fluid, 5 weight fork oil will do if you cant find "clutch fluid". The Black covered m/cyls use normal DOT 3 or 4 brake fluid. You will need to rebuild your cylinder if the wrong fluid has been used in it as the cups are made of incompatible materials. Kits to rebuild are cheap and it is best to replace all the parts inside with the new bits anyway. If your m/cyl is leaking (as you say) it needs rebuilding anyway, so do that and then double check that you have a small amount of clearance between the end of the piston and the lever. Your system will not work without this clearance. And for the interested folk still reading at this point, the only difference between the Ford m/cyl picture above and the m/cyls on our bikes is that we dont have the "inlet valve" which is actually a residual pressure valve in the end of the m/cyl. This is only used on Hydraulic Drum brake cars to keep the brake shoes out near the drum so you dont get a low pedal. Apart from that they work in an identical fashion, we have both ports etc and the piston/cups design is the same.

HTH,

Cheers,

Stork.

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