cos it seems very expensive compared to Dot 5.1 etc

Mineral oil for Citroen Hydraulic systems otherwise known as LHM.

halfrauds round here only seem to do it in a huge size @ £10.99 for 1 litre.

You could have a brake bleeding party?

1 litre is £15 from crc. I bought one 3 years ago and still have loads left.

Any mineral brake fluid will do. LHM ought to be fine too but you can get a little bottle of mineral oil from bikehut for about £4 and it'll last you ages.

Mineral oil for Citroen Hydraulic systems otherwise known as LHM.

Got to beg to differ I'm afraid…

Having tried it, Citroen LHM is MUCH MUCH thicker stuff than the Shimano mineral oil. It makes your brakes feel crap, if indeed they work at all!

The Shimano stuff isn't cheap indeed, but it works…

Halfords also do a small bottle of mineral oil in the bike bit.

clicky click to shop £4.99 for 125ml.

Having tried it, Citroen LHM is MUCH MUCH thicker stuff than the Shimano mineral oil. It makes your brakes feel crap, if indeed they work at all!

did you have the right stuff? I've used it successfully for several years.

Go to a motor factors like a Euro Car Parts or something. They sell the LHM fluid for much less than even Halfords. Think the last litre I bought was under a fiver.

Not all mineral oils are born the same…they have different viscosities and working heat ranges. Unless you can find out the properties of the oem shimano mineral oil then i wouldnt get any other oil.
Yes its expensive if you buy it in 50ml pots, but if you buy 1 litre its pretty cheap. Is it really worth the £10 saving (considering you use about 20ml per brake bleed so it lasts forever)?

some Magura brakes use mineral oil. I dont know if its the same but probably is.

http://www.chainreactioncycles.com/Models.aspx?PartnerID=79&ModelID=69

CRC do this more than enough to do do a couple of sets of brakes both front and rear. 4 quid posted. I have used it works spot on no difference from the red Shimano rip off stuff I have used in my other Shimano brakes.
http://www.chainreactioncycles.com/Models.aspx?ModelID=29899

It does seem expensive, but after doing my brakes with some, ooooohhh 'bout 5 years ago, I've never had to do them again. That's pretty good value

did you have the right stuff? I've used it successfully for several years.

Yup, bought a litre of Comma branded Citroen LHM fluid from a local motor factors (WAY cheaper than Halfords inflated prices incidentally if you happen to own a Citroen!), and bled my brakes with it… They don't work!

Citroen LHM is definitely a lot thicker. I understand it seems to work ok in Magura brakes, which obviously use more fluid per brake than Shimano do, along with bigger reserviors and pistons.

I went with the Unipart LHM oil part number GBF6103. Cost about £4 for a litre. Replaced out the old oil on my XT's front and rear and have had no issues what so ever. Also with having a litre i wasn;t too fussed about wasting any oil so made bleeding a hell of a lot easier 😆

When you say it doesn't work are the levers spongy or just no bite??

I got a 1litre bottle of LHM+ for about £6 from the local car spares shop and it works fine. Have done two sets of brakes so far with no problems in about 4 months (touch wood ;-).