Hi guys and girls,

Brought a set of used SLX Brakes off here a while back. When i got them, i understood that the rear brake had no fluid in and would obviously need a bleed. I’ve bled brakes before so i didn’t see this as an issue.

Anyway, I’ve now had two attempts at bleeding with no success. I cannot get fluid to push through into the lever, and if i try push down through the lever, it leaks out from under the ‘SLX’ lever lid.

I’ve got a shimano bleed kit as well as a funnel. I’ve tried bleeding from the caliper upwards, and also from the lever with no luck. I then removed the hose from the lever and pushed fluid up from the caliper and it came out of the end of the hose no problem, so my issue must be with the lever.

I’ve stripped down the lever body and gave it a good wipe down. I’ve used an old piece of brake hose with the olive attached and tried to blow air through the system but i cannot so it must be blocked in between the hose and the hole which fluid leaves the reservoir. If i fill the lever up from the top and then pull the brake lever, nothing happens, no fluid moves out of the system.

Has anyone got any ideas on how to unblock this? Has anyone had this issue before. I’ve now wasted about 100ml of mineral oil as i’ve tried bleeding it so many times. As i have said, the caliper and hose seem to be functioning normally, and i therefore must have a blockage in the lever.

Thanks!

new lever £30

Would rather not have to buy a new lever unless this one is no good

Idiot question you did have any bleed ports/covers off when you tried to blow it through with a airline and also open and closed the lever to open the internal ports/valve? apologies if you did.

It does sound like maybe something is lodged internally like a piece of swarf/grit.

I’d strip it as fully down as possible and then give it a sharp tap on a wooden surface to see if you can jolt it loose.

Failing that as a last resort I’d stick a stiff piece of wire through to see if you can dislodge the obstruction.

Thanks for the reply unovolo,

I had the lever fully stripped out at the time, attached an old brake hose with an olive and the fixing nut to the lever and tried to blow and could not get any air in, so it must be blocked between the hose connection and main reservoir. (I did blow through the hose before attaching to check that wasn’t blocked)

Yeah, i believe there must be something in there. This being second hand, i don’t know what the previous owner did. Maybe the brake stopped working, or maybe it was a dodgy bleed and something foreign went in with the fluid.

I already tried an unbent paper clip but that didnt solve it…

I will give it a couple of taps tommorrow. I remember i had an issue with my iPhone microphone, 3 hard taps on my thigh and it sorted it out!

Don’t the seals on Shimano brakes swell up if you put DOT brake fluid in? Perhaps that’s what’s happened? This is a wild guess. Certainly DOT ones swell up with mineral oil.