Well I’ve used Castrol LHM in all my Shimano brakes over the years (probably 10 years+) without any obvious issues.
My current M775s have been on the bike for 8 years and they were second hand when I got them.
So I can say with some confidence that in my experience LHM is fine to use with Shimano brakes.
Obviously Shimano are going to say only use their own stuff, they have a vested interest in doing so.

They’re my brakes.

Shimano say ‘use our oil!’ so I use their oil. Really don’t see the point in messing around to save a few quid.

I can never seem to push the oil from the bottom up so just go in from the top now

I had this problem when I first tried bleeding my Avid brakes by following a you tube tutorial. After lots and lots off faffing I realised that I had been following the (american) video so exactly that I was trying to bleed the front caliper to rear lever.

Do you know for a fact or did you just read it on the internet?

Been using it for so long, I can’t honestly remember. Although last bleed on my road bike brakes I used Juice Lubes mineral oil.

epic bleed kit. bleed form calliper up, don’t have to take brakes off bike, can do it in 5 minutes and get a good bleed every time

So I can say with some confidence that in my experience LHM is fine to use with Shimano brakes.

Shimano used to be very reliable didn’t they? And then they started having seal problems more recently? So perhaps your 8 year old brakes are ok with any old oil, and the newer ones are more sensitive?

(actual question not being snarky)

You might be right, although given the number of reported problems when people haven’t changed the oil I suspect its a shimano issue rather than a fluid issue.
This is one of the main reasons why I reluctant to chnage up from my M775s!

I found LHM to be a tad slow on the levers in the past, and since then only use shimano oil.

Shimano 1ltr is only £13 so not expensive.

But the thought I might make it worse or more likely by using non-standard oil against recommendations for the sake of what, £6 or so made me choose Shimano.

Shimano 1ltr is only £13

It is? I paid £12 for a tiny bottle!

I have used LHM on my SLX and Zee brakes. They worked OK for a period, but never really got the bleed perfect. I picked up the LHM stuff from Halfords, in the bargain bucket section when I was frantically looking for fluid. Was about £3 for a litre.
Assuming it’s related, but I also had pistons leaking and master cylinder sticking (when cleaned it was full of gunk).
Switched back to the proper stuff and been better, I do still get the wandering bite but only when pads are very low.

I use this German site for bike parts, when i need to stock up on bit and pieces, but you do have to get over min over value, although even with carriage its still cheaper than CRC for some parts. funny enough i use a Germany company for pet food too as its cheaper than the UK, obvisously not the same one 😉 .

https://www.bike-discount.de/en/shop/workshop-1884?currency=3&delivery_country=190

Shimano 1ltr is only £13

It is? I paid £12 for a tiny bottle![/quote]It’s worth buying in bulk as it has a very long shelf life – even once opened.

I use this German site for bike parts

Better stock up then before 2019!