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When bleeding my front brake, a large amount of fluid purged itself out of the outer end of the lever barrel. It started when I pushed the pistons back, but carried on under gravity with the fluid filled reservoir attached.
After putting everything back together, it seems OK but I'm pretty sure fluid should never come out of this hole which, I believe, is to allow air in (not into the system proper) to allow the compensation for pad wear.
From reading on t'interwebz, I think the lever is ****ed if any fluid makes an escape via this port. I've probably overfilled it at some point and then pushing the pistons back has popped something...
Any advice, please?
Yeah the fluid has been forced past the diaphragm in the lever. I’ve had it happen years ago with no ill effects, so would happily ride it assuming it’s now bled nicely.
The areas that’s leaked isn’t under pressure when using the brake. So shouldn’t explode and kill you right away
I had something similar happen with an SLX lever last year, albeit to a lesser extent from your description. The lever's still fine and working.
Replacement diaphragms are available if it is damaged.
It's had a cable tie around the lever for about 5 hours this evening. No more fluid has appeared, no slop in the lever.
I'm going to say I might have got away with this one...
As above, have replaced the diaphragm on an slx lever. I had weeping out the hole and this fixed it, think shimano even had a video how to replace it. Be aware there is a grub screw holding on the cap at the end of the tube that the fluid was leaking out (possibly also keyed, but can’t remember totally)
edit here’s an eBay sale showing the exploded parts diagram and the bits you’ll need to replace, be aware there is two similar parts, one with a slanted end to the diaphragm and one square
Recently did exactly the same to an XT lever, lever continued working fine although some fluid did occasionally leak.
I purchased a diaphragm and fitted it in no time, the old diaphragm had a small tear in the rubber but I'm sure it would've been fine if I didn't change it.
I've done the same thing. It was fine generally but I ended up replacing the bladder.
As the pads wear, the piston moves further out. Because there's no reservoir for additional fluid, you can end up with a vacuum occurring in the lever. The bladder allows the pressure to balance to prevent a vacuum from occurring. It's a minescule amount of movement really but it's necessary to compensate as the pads wear down.
With a perforated bladder, you'll find as the pads wear that air will get inside the system and you'll be forever bleeding the lever.
The bladders are cheap enough. Just make sure you get the right one as there are 2 different types. You'll need the XTR version for SLX brakes
A lot cheaper at SJS compared to that eBay link, even after adding postage. One of those 'just in case' bits it'd be worth adding to a bigger order.
https://www.sjscycles.co.uk/brake-levers/shimano-xtr-blm9120-diaphragm-unit-y1xk98030/
you can buy these for 2.99 at freewheel.co.uk, and get them delivered free to a local bike shop