Repairing Magura HS11 brakes

I’ve been asked by a friend who has a bike with older HS11 rim brakes, how best to repair them. On initial inspection, they seem to need bleeding as a minimum. Bike shops are very busy right now, and not many have expressed much knowledge of these brakes, most seem to be just saying ‘replace’. I’ve had a look, but they’re not something I’m familiar with, although I’m assuming hydraulic systems are pretty much the same thing in principle. I’ve bled and serviced Hope, Hayes and Avid hydraulic disc brakes before, so I’m wondering if there’s anything radically different I need to consider, before embarking on such a project? They seem to need new hoses for a start; they don’t seem to be leaking, but they are definitely a bit ‘tired’. Are such brake sworth time, money and effort to fix? Or is it just more in landfill and start all over again? Standard brake boss fittings, so V-brakes could easily be fitted. Friend would really like the Maguras though as he likes the power they offer. Any advice gratefully appreciated.

All I know is trials riders use HS33 which are the more powerful version. There’s service docs available at https://www.magura.com/en/components/techcenter/ if you have an idea of year?

Bleeding is ok on these with the right kit / fittings. I used proper Magura ‘Royal Blood’ I think it was (posh mineral oil I believe) when I had some hs33’s.

My memories from first time round that I had them was of them being awesome and not needing much adjustment (Johnny R’s from brand new in the mid-late 90’s).

I got some more a few years back for a budget / slightly retro hardtail build I did – just found them a massive faff and couldn’t get them to perform anything like even a Sram Guide disc brake.

If disc brakes aren’t an option then Maguras do edge out v brakes and feel nicer at the lever – but I’m not convinced for day to day riding it’s worth the effort. If your mate carries on with them I’d suggest he gets upskilled on what he needs to do to maintain them – otherwise it’s potentially a world of pain for you!

There’s nothing dramatically different about them. You’ll need the specific bleed kit and some mineral oil. HS11s are pretty basic. A decent V-brake setup will probably outperform them but then unless they’re nailed you should be able to resurrect them.

If the levers themselves or the caliper units are leaking through the seals I’d probably get rid.

Had a few back in the day. The time consuming bit was the initial fitment – the brackets could be flipped round for different canti stud spacings, so there are multiple positions of brackets / horns / qr lever / booster plate that may or may not work.

Bleeding is very basic as they were a closed system without a master cylinder – you just pushed fluid through with a syringe and then a pipe at the far end into a jam jar. I always just used LHM fluid.

Fantastic stuff people. Thanks.

There’s service docs available at https://www.magura.com/en/components/techcenter/ if you have an idea of year?

Yes they’re a bit older but I think there’s info available on them, thanks. Was just wanting to know if they’re worth doing, or ‘beyond economical repair’.

The ‘mineral oil’ thing; it is just LHM fluid with some dye in, isn’t it? I seem to remember something about this from years ago, when a riding buddy had some.

Mineral oil is a pretty non-specific term. It covers everything from official oils for brakes/forks, LHM fluid, baby oil and vegetable oils. There are some synthetic oils that are potentially harmful to seals used in mineral oil brakes, so you shouldn’t use any DOT-spec fluids, for example.

I’ve used vegetable oil in Maguras. It was a bit slow, not recommended. LHM is fine too. Some people advocate water (which is actually fine unless the bike ever sees 0°C). But otherwise any mineral oil intended for bikes / cars is probably OK.

Mineral oil is a pretty non-specific term. It covers everything from official oils for brakes/forks, LHM fluid, baby oil and vegetable oils

Er…