My L-Twoo ER9 hydraulic front brake recently went spongy.
I installed the groupset brand new last August and it has been fine up until a few weeks ago.
I was out on a ride when I pressed the front brake and the brake was spongy.
When I got home I bled it and got air of it.
All was ok after that for a few weeks until it happened again?
I did make sure to bleed it properly but there is air in system again.
I have the V3 ER9 groupset with the seals on the air screws on the shifters.
Do you guys think something is drawing in air somewhere or maybe I've missed some air trapped in the system?
I have bled Shimano brakes more than a few times successfully,so it's not like I'm inexperienced with hydraulic brakes bleeding?
So what was your fix to this?
I have same issue on ER9 V1. Brakes are shyte IMHO
Still looking for a solution
I have read some reports of the master cylinder seal drawing in air
Maybe your brake screw isn't tight enough or there's an air leak. You could try these newer LTwoo pieces that come with a rubber gasket to minimize air leak.
https://www.aliexpress.us/item/3256809723608391.html (https://www.aliexpress.us/item/3256809723608391.html)