Hello,

Can someone tell who makes those OEM hydraulic disc brakes? It has what looks like two oil ports on top.

Magura? Shimano? Other?

Cheers,

Their website says they use Shimano or Magura. Never seen a Shimano with two ports on the reservoir, therefore I say it is Magura.

That looks like the master cylinder that comes with the "MEROCA M4S", possibly also supplied with Clarks branding. No information readily available beyond what's on Amazon, AliExpress etc.

FWIW, the calipers have two pistons, and use the same pads as Shimano BS05. The diameter of the oil port is 8mm.

Can you tell it's mineral oil, or DOT? If the former, I could burp them with the oil I already have.



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Edit: Turns out a Presta-to-Schrader valve adapter fit the Shimano funnel. So I went ahead, and burped them with mineral oil. If it was the wrong fluid, I'll give my body to science fiction.

If it's the one I think it is then it uses mineral oil.

Certainly not Shimano, Magura, SRAM or other quality manufacturers. Some sort of Shimano-esque knockoff probably from a random factory somewhere. I would reach out to Vello to see what fluid they use. I would never guess with that and actually double check and confirm before proceeding forward. Honestly though a pair of MT200s would be a better option in most cases where they aren't using a known quantity and quality brake.

the Meroca brakes for sale online all use Mineral Oil.
Shmano uses Mineral Oil.
all Shimano clones use mineral oil, as far as i know.
Magura "Royal Blood" fluid is Mineral Oil
even SRAM, one of the last "DOT" user holdouts have now switched to Mineral Oil, as of last spring or so.

now... has anyone here ever evacuated the DOT 5.1 from a brake system, then switched to Brake System grade Mineral Oil? (there are multiple products called Mineral Oil, but not all will withstand the heat in a brake system..)
just curious.
i bet it works fine.

when evacuating a brake system, repeated flushings with iso. alcohol are required... i then leave the system open overnight, and use dry air to get any remaining alcohol out before refilling with a different fluid... this was done to several race cars and motorcycles over the years... and one 135cc Margay/Comet Race Kart owned by me..all were switched to Motul 600 DOT 4 fluid.

They do still use DOT in their road products, Hayes is still DOT, Hope is still mostly DOT and Formula I believe as well still uses DOT.

Hayes has specced DOT4 and 5.1 over the years.... confusing to many, i'm sure...

Hope is jumping between types, and can be either DOT 4, 5.1, or Mineral oil.
not a good look for such well built parts, IMO.

if Formula hasn't converted by now, i'd be surprised.

other than the switched spec brands, the problem becomes outdated, non-model specific info still up online, and no date on many of the articles, or the Parts involved, which is the reason for this thread, and a few others too .

the best course would be physically stamping the parts with the fluid type needed.... and should be done to all hyd. brake components, not just bicycles. M/C brakes have the fluid type cast into the master cylinder covers...
when i was racing the Kart, the only info source was the word of any local Karting guru ... all of the ones i saw or used, used DOT4 back then.... some tried the latest/greatest new thing, and regretted it.. DOT 5 and 4 don't play well together.

Hope is doing pretty much all DOT they make a caliper for road that is mineral compatible but it is only a caliper no levers.

I would agree marking what fluid is crucial but sadly with the abundance of cheap no-name stuff it is unlikely.

For what it's worth, DOT fluid has a rather...particular smell to it that other LHMs do not have. On that merit alone, it is reasonable to not necessarily HAVE to call the manufacturer.

That said, if it's a bicycle product that wasn't designed in the American continent or Europe...it probably wouldn't be DOT fluid. There are probably systems out there, but other than SRAM, Hope, and a few boutique makers in the eastern parts of Europe...pretty much everyone else is using mineral oil for bike disc brakes.

Even it was mineral oil, it would be prudent to completely flush it. Just because they're both mineral oil, doesn't mean they're both friendly with each other.

Since I just did a burping, only a minimal amount of fluid was added in the process. I took the bike for a spin yesterday, and it braked fine… so far.