Author Topic: Oil for Hope hydraulic disc brakes (Read 2517 times)

Polar Bear · « **on:** 26 August, 2008, 09:38:28 pm »

Found a leaky joint which I have carefully tightened. I need to put new oil in.

Anybody know what the spec is please?

Craig · « **Reply #1 on:** 26 August, 2008, 09:45:24 pm »

I'm pretty sure that all Hope brakes use DOT 5.1 brake fluid (available from Halfords etc).

You can get the manuals for them on Hope's website: Hope UK - Frein Hope

Polar Bear · « **Reply #2 on:** 26 August, 2008, 09:50:24 pm »

Excellent. Thanks Craig.

Becky · « **Reply #3 on:** 26 August, 2008, 11:30:58 pm »

My Hope Minis use the DOT 5.1 from Halfords, too. You can buy fairly small bottles, 250ml or something, for not too much money.

cometworm · « **Reply #4 on:** 27 August, 2008, 07:40:51 am »

Quote from: Becky on 26 August, 2008, 11:30:58 pm

My Hope Minis use the DOT 5.1 from Halfords, too. You can buy fairly small bottles, 250ml or something, for not too much money.

Don't mix oils btw - I think Hopes can run either 4.0 or 5.1, but don't mix them...

Jacomus · « **Reply #5 on:** 27 August, 2008, 08:47:33 am »

Hopes can use either 4.0 or 5.1

Mixing the two is a Very Bad Thing

Mixing old and new is a Bad Thing

DOT5 must be avoided at all costs!! It is completely different to DOT5.1 - it is silicone not glycol based.

DOT5.1 has a higher wet and dry boilling point that DOT4, so brake fade is reduced (but not by very much, the two fluids are very very similar).

The main difference is their relative viscosity - DOT5.1 is less viscous than DOT4, so you will get a slightly lighter lever action. Available power is not affected AFAIK.

Once opened, DOT4 or 5.1 become useless i.e you cannot store them as they absorb moisture. Cloudy or dark brake fluid is ruined, and has become saturated with water and should be changed.

Download Hopes service manual for your brakes and follow the bleed instructions, taking MASSIVE amounts of care not to get any brake fluid on any painted surfaces.

Becky · « **Reply #6 on:** 27 August, 2008, 06:42:06 pm »

Quote from: cometworm on 27 August, 2008, 07:40:51 am

Don't mix oils btw - I think Hopes can run either 4.0 or 5.1, but don't mix them...

Given that mine have been emptied, filled, bled, emptied, filled and re-bled several times each over the years, that hasn't generally been a problem for me.

Polar Bear · « **Reply #7 on:** 27 August, 2008, 08:59:27 pm »

Thanks for the info folks. A trip to Halfords beckons then.

Polar Bear · « **Reply #8 on:** 13 October, 2008, 08:15:32 am »

There is no doubting that when working hydraulic is a good system. However, take my Hopes, (please!!!!). I spent ages sorting out one of the brakes, the rear. Where the pipe comes out of the lever there is a 90 degrees junction. This was 'weeping'.

With valuable advice from many people here I sorted it, bled the system and all was well. Then, wheeling the bike out of the workshop this weekend whilst shuffling bikes I managed to knock the lever and the pipe. The pipe turned on the junction. As I'd knocked the lever at the same time some fluid escaped.

It is a weak design, poorly implemented in my view. It isn't suitable for the bent either. A system without that 90 degree junction would be far superior, such as the Shimano one. However, I realise that these expensive Hope hydraulic disks are overkill for the bent so they will go, next spring. Avid or Shimano cable, or Shimano hydraulic disks will replace them and I know that I will not be down on usable braking power.

Jacomus · « **Reply #9 on:** 13 October, 2008, 08:35:42 am »

AFAIK this was a design problem with some earlier Hope models, I'll have a poke around, because I think it can be sorted by buying a new style brake hose.

I'll post back here if/when I find anything.

Polar Bear · « **Reply #10 on:** 13 October, 2008, 08:52:12 am »

Quote from: Jacomus-rides-Gen on 13 October, 2008, 08:35:42 am

AFAIK this was a design problem with some earlier Hope models, I'll have a poke around, because I think it can be sorted by buying a new style brake hose.

I'll post back here if/when I find anything.

That would be interesting. Thanks.

Polar Bear · « **Reply #11 on:** 13 October, 2008, 10:11:38 am »

Would this be what I'm looking for, maybe?

Jacomus · « **Reply #12 on:** 13 October, 2008, 11:11:06 am »

Could well be, though it might be for the lever-hose interface.

Have you got a pic you can post with the rear set up and 'kinked' hose?

Polar Bear · « **Reply #13 on:** 13 October, 2008, 11:42:53 am »

It's the lever end I need. That's where the troublesome joint is...

Jacomus · « **Reply #14 on:** 13 October, 2008, 12:50:40 pm »

Quote from: Polar Bear on 13 October, 2008, 11:42:53 am

It's the lever end I need. That's where the troublesome joint is...

Aha! In that case, it looks like you found it!

Worth double checking with Hope - IME they are men of very few words, but helpful.

Polar Bear · « **Reply #15 on:** 13 October, 2008, 12:55:30 pm »

Ah, excellent. Will do.

Though, given the current routing fitting the new gizmo will also mean buying and fitting new hoses too. Oh, the pain ...

It will have to be put on hold until spring now though - too much happening right now.

PhilO · « **Reply #16 on:** 13 October, 2008, 01:58:23 pm »

The straight and bango connectors are interchangeable, and use the same fittings at lever and caliper ends, so you should be able to swap and change at will. (This is true of my XC4s and C2s, anyway).

Note that the OD of the hose used has been reduced from 6mm to 5mm in recent years. The 6mm hose can be hard to get, so you may want to change the whole setup to 5mm. If you do, you'll need to also change the fittings at the other ends - expensive! When I moved mine between bikes recently, I got around this by using Goodridge 6mm hose - expensive per metre, but cheaper than a full set of connectors.

Quote from: Jacomus-rides-Gen on 13 October, 2008, 08:35:42 am

AFAIK this was a design problem with some earlier Hope models

Which lever? I've not come across that problem in a decade of MTBing...

My elderly (C. 1999) Hope brakes use the Pro Lever which uses a banjo connector. This cannot turn relative to the lever body, because it sits between two locating lugs.

The Sport Lever doesn't have that support, but would normally be fitted with a straight-through connector, anyway, as shown in the drawing.

The more modern Mini Lever is similar to the Sport in that respect. I have seen people run these with banjo connectors, though, for tidy hose routing.

Polar Bear · « **Reply #17 on:** 13 October, 2008, 09:44:11 pm »

From looking at those the levers appear to be the Mono Mini levers but with the banjo fitting. Not such a great idea IMO.

PhilO · « **Reply #18 on:** 14 October, 2008, 09:14:23 am »

Quote from: Polar Bear on 13 October, 2008, 09:44:11 pm

From looking at those the levers appear to be the Mono Mini levers but with the banjo fitting. Not such a great idea IMO.

No. It only makes sense if you tie the hoses back against the stem, and most people run their bars too wide for that.

Fortunately, the solution is simple: Buy one of these for each lever, fit, bleed, job done.

Be careful to get the right diameter fitting, obviously, and you may need to get some new hose as I guess that the existing ones probably won't reach with the new routing...

Tip: (With apologies if I'm teaching Granny to suck eggs)

The barbed bit which sticks into the hose is easy to snap off if you try to pull it out. To remove a fitting without damage, cut the hose 3/4" short, then use a knife to slit it lengthwise to remove from the barb. Don't ask me how I learned this.

Tip 2: The olives are split, and can be reused after easing them open with a knife blade.

Polar Bear · « **Reply #19 on:** 14 October, 2008, 09:34:11 am »

Thanks PhilO