A friend bought me his wife’s Fiido City II e-bike to fix. “Can you fix the brakes on this please?” Sure enough they were spongy and useless as anything. “Let me see, I’ve not done it before but it can’t be difficult”. Anyway, I sourced a brake bleed kit for e-bikes (why they don’t put bleed nipples on is a question for another day), sorted the front brake no problem, it’s brilliant now. I just can’t sort the rear though, tried everything over the weekend, hardly any better at all. I strongly suggest there’s a small leak somewhere, preventing full pressure from building. Looking at the cost of these things it would seem to be cheaper to replace the entire rear brake ie master cylinder, caliper and connecting hose. But, what’s a good, reliable make to get? HEL eMTB stuff at €300 is probably OTT, but Aliexpress options at €20 are almost definitely not worth it. I know a good few of you have e-bikes here, what are your recommendations please?
Are these bicycle style disc brakes? There are plenty of YouTube videos on how to bleed bicycle disc brakes.
Yep, bleeding them or rather flushing new fluid through top to bottom was not an issue. The issue is there’s a small leak on the rear circuit so pressure can’t build hence the request for advice on replacement m/c & caliper set. There is definitely no air in the system. It’s a fault with the components.
The lack of bleed nipple is cost and size/weight IMO. I'm going to go with your theory that the line has a leak at one of the other ends. You should be able to purchase replacement hose inserts and olives easily enough and it's a simple task to repair IME. As for replacements should you go down that road my Son rates Shimano Deore on his Hardtail and he rides some Sketchy trails on his hardtail. I'm assuming your friends wife just rides for leisure and nothing gnarly? I'd buy Hope but I'm a tart and love anodised tat on my bikes and carbon. If the budget is tight Clarkes brakes from Halfords work well and are as budget as I'd dare go hydraulic wise. I am however a fan of cable actuated calipers having used them when cycle touring, effective on 20-30 mph descents fully loaded all up weights of 100kgs give or take. They were as equal to hydraulic calipers in my experience as the ultimate limit with bicycles will be the tyre and or rider skill.
