Is it just mine or do everyone’s Shimano Discs play up in the freezing ? Mine seem powerful enough but the “feel” has gone from them if you know what I mean ?? My mates’ Hopes feel wicked, I was thinking it was down to the different fluids used ???

There are a few other threads about this already, you are certainly not alone! My front brake is currently fine, but my back is almost jammed on!

Mine are pretty much fine…

out of interest, what fluid are you using? Genuine Shimano or Citroen halfords stuff? Mine have been okay so far with the citroen stuff

Genuine Shimano here, didn’t realise there was an alternative out there

“Taste the difference” Extra Virgin…

Mineral oil is mineral oil, supplier is of minimal importance, better not to use an old previously opened bottle if you can help it though as this tends to leave it a little more aerated over time…

Could be that brake fluid is hydroscopic ie

It attracts moisture not air it could be that people have moisture in there fluid possibly causing tiny ice crystals to form

This could possibly block one of the transfer ports in the system causing brake probs

I have never heard of needing special brake fluid for cold weather

Imagine having to take your car in for a fluid change in the winter months or cars and trucks having brake failures due to the wrong type of fluid ?

Bleed brakes new fluid problem solved minus 7 on Monday on the commute no problems

cookeaa – Member
Mineral oil is mineral oil, supplier is of minimal importance

Not so sure about that, given the LHM stuff seems to be quite a bit thicker – composition could well be different also.

It won’t be the fluid that’s freezing. Maybe water in the pistons, but not the fluid. And a different fluid won’t make 2 different brakes feel different either, that’s just the design

It might not freeze but it will get thicker – how much exactly I don’t know but it definitly affects suspension too. Can’t say it’s ever caused a problem for me but then I’ve always used brakes with DOT fluids which are going to have different properties.

Engine oil and hydraulic fluids thicken appreciably on cold days and significantly affect the performance of cars and other machinery during the winter months. In general, the viscosity of a simple liquid decreases with increasing temperature (and vice versa).

http://physics.info/viscosity/

mine are fine*, if anything theyre better than I remember them

Rear calliper is on its way out though, fluid is an emulsion when I bleed it.