After my recent 12 hour mud fest during which my bearings seized and my Magura HS33 cross over brake line parted, I noticed that I think I’m missing a part from my brake system? It is very hard to describe, but there is a connection piece that connects the brake lever (lower side that is inside the brake housing) to the hydraulic system itself. The brake lever is still connected to the outer housing but you know there is this dangling piece of metal that hangs from near the bottom end of the brake lever that is supposed to connect to some part within the brake lever housing? Anybody know what I’m talking about? You see after the cross-over tube parted and the whole system went slack I still had several miles to go to finish my first loop. During that time the brake lever was very slack and just pivoted freely. I think sometime during the rest of that loop (but before I removed the brake system after the loop) some connection piece must have come free to be, still, buried in the mud out there somewhere! If you could just post a photo of what the brake lever attaches to at the lower end, not the pivot point of the brake, but to the actual hydaulic line that would be great. Better yet if somebody knows the name and part number of this piece and where, if possible, it can be ordered from! I’ve fixed up the brake system but I know there must be a missing piece. And before you suggest it, the part doesn’t appear in the list of spare parts in the owners manual???
Anyhow, I’ll try and post a picture of my brake system in question when I get a chance…
You’re talking about the pushrod, which presses asgainst the top of the master cylinder. Can you take a photo so we can see which part is actually missing? From your description it sounds like it might have just become disconnected.
It looks like this. But I think your threaded rod has come out of the depression in the end of the cylinder, due to the lack of fluid to hold it there. If this is the case, you can back the screw out and put it back in position.
Here’s all I have in my brake handle… (sorry if it’s a bit fuzzy)… as you can see there is nothing for the end of the metal push rod on the brake handle to connect to inside the yellow brake housing. Any guesses? I know, I know mine is a bit “older” system.
ah, right that’s the piston of the master cylinder. I don;t think they sell tem seperately, you might have to buy a whole new handle unit. Personally I would dig round on ebay for a broken one and rob the cylinder out of it.
Can you take a better shot of what is left inside the lever body. Looks like the cylinder piston is still in there, but can’t tell for sure. The pushrod end sits loosely in a ribbed plastic cup (that is the end of the piston). This cup cradles the push rod end and is held in there by the spring behind the piston.
If you lose fluid pressure and then mud gets in the cylinder or the cylinder gets dry, the piston can stick in the cylinder and let the pushrod come out and flop around. Make sense??
I have some old style levers.
brycer1968: All thta is inside the lever body is that “ribbed plastic cup”. Is that all that should be there? So I just need to flush the whole line out (clean out whatever mud and particulates may be in there) and then re-bleed the system? Just seemed kind of odd that the pushrod would have so much play inside the lever body?
Thanks everybody for your help. I’ll clean things out and try rebleeding unless I hear something otherwise… not having another magura brake it’s difficult to tell what is and what isn’t missing!
I think you are on the right track. . . . Tap the ribbed plastic cup (piston) out and clean it, the spring in front of it and the cylinder it rides in. (It might take some sharp tapping to get it out) Flush the lines that might have mud in them.
Lube up the cylinder and piston with fresh Maggie blood and reinstall it and the lever and lines, bleed twice and you should be good to go.
If the piston sticks again, you could take it all apart again and try lightly honing the cylinder with 000 steel wool wrapped around a wooden dowell (use oil on the wool too). Just a couple dozen revolutions by handshould be all it takes to remove/reduce any scoring, but go easy as a little goes a long way.