My wife's bike has the old Hope Mono M4 brakes. (Slightly over-braked I know- we bought the bike with them fitted.)
She doesn't get as much chance to ride as we'd like, so the bike gets infrequent light family (trailer-towing) use. Over the last 12 months, on a couple of occasions the brakes have jacked fully on so the lever cannot be moved. Bleeding a little fluid from the bleed nipple corrects the fault.
Although I'd like to think I got a mechanical knowledge, I'd have thought that the more likely fault that the lever would become soft if there was a leak of fluid or air in the system (I've noticed no leaks).
The only explaination I can think of is that there is some moisture in the system, and as Dot 5.1 fluid can absorb moisture, it has in some way got moisture in.
Does anyone have another explaination?
I've never bled the brakes. I've bought some silicone tubing and a syringe. It appears fairly straightforward*. DO you think a bleed will solve the problem or could they require seals/pistions? I think if that was the case I'd replace them with some lighter brakes more suited to her riding style!
*Will any Dot 5.1 synthetic automotive fluid do the trick or does it have to be Hope?
