Just picked up some Helfrauds automotive 5.1 to do a bleed on my X2, buy now im home ive noticed it says it non silicone based! Is this ok to use ? Also what sthe best way to bleed them to get a really firm lever?

Cheers

i use halfords 5.1 in all my hope brakes

no problemo

a few aisles over you can buy presumably the same 5.1 for 3 times the price, but its mtb specific?!

So NON silicone is fine?

If it says Dot 5.1 on the tin then it is Dot 5.1 so should be fine…I hope so anyway as I’ve been using it for the last 8 years without noticing any issues with my braking!

Cool, cheers all.

Currently using Halfords DOT5.1 in my Hope and Avid brakes – not had any issues. Always buy brake fluid from car parts section, much cheaper. As long as it is DOT5.1 you can use any brand.

5.0 is silicone based. You really don’t want that in hope brakes. 5.1 is 5.1. It does the job in my brakes and has done for years.

check the ‘how to’ video on hopetech.com

I use it in my M4’s!.

5.1 is 5.1 is 5.1 – it’ll be fine

I struggle with the second part of your post OP – I do a good bleed as per hope site, with BP wound out but then the lever still moves more than I’d ideally like – even on new pads – before biting. Winding in the BP again all the way makes it just about acceptable and the brakes then work solidly from then on.

I’d just like to know how to eliminate this excess travel like the OP I guess as my mates M4’s are better in this respect.

Ditto pedlad…

Once I’ve bled mine, the lever does move alot until I’ve set the pads to the rotor. Push the back of the pad over with a little screwdriver to the rotor, then press the lever to take up the space between the pad and rotor. Do the same with the other side and repeat to centre the pads to the rotor. That way the slack space will have gone.
Hope that solves that!?

Discounting the adjustment dial for the bite point, how far the lever throws is a function of the seals and piston bores, not the bleed.

However, regarding the bleed, I always finish mine with the lever off the bars and the plug out and the lever blade pointing down. My final step of the bleed is to push the pistons back and allow any excess fluid and final bubbles of trapped air to escape from the mater cylinder through this plug. That way, the port into the master cylinder is vertical and gives and air the best chance of escape.

Not the case that all 5.1 is the same as some seem to think- different 5.1s have different boiling points. But, the Halfords stuff will certainly work fine.

true, but 5.1 is a spec so they all meet a minimum standard which is more than enough for bicycles.

People do still manage to cook brakes though (Hope more than most it seems!)

(FWIW I use Halfords stuff in pushbikes, car and motorbike)

Just a wild guess with no evidence to back it up, but the people who boil brake fluid wouldn’t be any better off by switching brands. I can’t imagine the over heating would sit nicely between two different boiling points of 5.1

It’s got to be(wait for it) a matter of degrees (ba-dum). Something like SRF (which is a DOT4) boils significantly higher than the base spec for 5.1 when dry, but also has a much higher than typical wet boil point- which is good for the maintenance-intolerant.

I reckon it’d make more sense for people with boiling issues to get more appropriate brakes, though, or stop being dobbers.

My mate used this stuff http://www.apracing.com/products/road_car_upgrades/brake_fluid.aspx in the Hopes I now have. Still manage to achieve fade 🙄

The warning on the Halfords Dot5.1 bottle that it is

not silicone

, is so that you do not mistake it for Dot5.
Dot 5.1 has toxic, corrosive, paint-stripping properties (do not spill it).
Dot 5 silicone is less harmful.
Dot 5 has some advantages over Dot 5.1, but has gone out of fashion for cars etc because it is not ideal for cars with ABS (Advanced Braking Systems), plus it is purple.

I can’t imagine the over heating would sit nicely between two different boiling points of 5.1

What northwind said, the specs are a minimum, a lot of track cars use good DOT4’s and change it more frequently as they have higher dry boiling points but drop quickly with moisture which would be dangerous in a road car where it’s only changed after a few years, and the sytems in road cars are pretty poorly sealed compared to MTB’s.

Dot 5 has some advantages over Dot 5.1, but has gone out of fashion for cars etc because it is not ideal for cars with ABS (Advanced Braking Systems), plus it is purple.

Was it ever in fasion? It was used in show cars as you could just wipe it off without damageing paintwork, but for actual driving it’s crap (low ish BP, relatively compressible, imiscible with water (so it pools at low points and rusts through the pipes).

“fasion” ? no
but is still used by United States in military vehicles.

Alternative way to bleed brakes

but not ideal if there is dirt in the bleed nipple

“imiscible with water (so it pools at low points and rusts through the pipes). “

Are Shimano and Magura wise to use mineral oil instead of water absorbing glycol based fluid?

Makes one wonder how Rolls-Royce, Bentley, Citroen (using LHM) can cope without the water-absorbing (cleaning?) properties of Glycol fluid (Dot 4 and 5.1)?

Would Harley Davidson be better off with glycol dot 5.1 instead of silicone dot 5?

This article gives some good (and the negatives of Dot5) info on brake fluid
http://www.mossmotors.com/SiteGraphics/Pages/brake_fluid/page1.html

Dot5 is not ideal for all brakes but, it still serves the purpose that it was introduced for.

@ Onzadog – What do you mean by plug?

@ stevo210 – do you mean this http://www.youtube.com/watch?v=akIWGqEE0PY