Riles

I lost some of the Hydraulic oil in one of my mono Mini's Hopes... & it now doesn't work...

Does anyone know if I can simply top up the oil, or do I have to now do a full bleed process to ensure no air is trapped ?

Thanks

mx_599

i have hope brake knowledge. you need a bleed technically and hopes are about the easiest of mtb brakes to bleed.

however, top it off...test it out....does it work to your satisfaction? if yes, don't bother bleeding

i have given explicit directions and supplies needed to bleed hope's in a past thread. if you take the master cyl cap off, you're about halfway done with the bleed process, i don't know why you wouldn't go all the way?

mvonb

Also make sure that you only use DOT 5.1 fluid. Not too sure if this has the same name if you are outside of Europe. I would always go for a full bleed, just to ensure that the fluid is fresh and water/air free. Easy enough to do as a one man job with the hose, syringe full of fluid and a spanner. Make sure you take the brake pads off and block the pistons up.

Hank Rearden

DOT 5.1 or DOT 4. Just don't mix the two. Do a full bleed when switching between the two types.

mvonb

Hope recommends DOT 5.1 over the DOT 4. I would assume that this is because the glycol based DOT 4 can absorb water more readily than the silicon based DOT 5.1. Even in a perfect set up, there is a tiny risk of water ingress, so I would stick with the DOT 5.1.

Hank Rearden

I've used DOT 4 per their recommendation for years, without problems.

DOT 5.1 is more difficult to find in the US. DOT 5.1 does have slighter higher dry and wet boiling points but with the relatively low temps that MTBs generate, I doubt it makes any practical difference.

Both types are hygroscopic.

mvonb

In the UK DOT 5.1 tends to be of a higher quality than DOT 4. My old man was a truck mechanic and the garage was always full of brake and clutch fluids, he knew if I had been playing with them. I lost count of the 'new' bottles he had to throw after I had been opening them. All in the name of flammability testing. Now that I need the fluid for something constructive, I have to pay. What are you running on your rigs? I'm currently on M4s on my XC rig and looking for some new pads. Any suggestions?

Hank Rearden

I'm running M4s with EBC greens and Mono M4s with stock pads. No complaints.

mx_599

DOT 5.1, 4, or 3 can all be mixed to the original poster. don't worry about this. also, it is not necessary to take the brake assembly off the bike. no need to use anything between the pistons besides the rotor itself. syringe not necessary either. pour fluid in MC and use a couple feet of clear tubing from a hardware store on the caliper bleed valve with a closed end wrench put on before the hose.....

see old thread

mx_599

https://www.bikeforums.net/showthread...t=ace+hardware

all brake bleeding is generally the same...yes, your goal is to reduce the bubbles to as little as possible in the fluid draining out.

someone will answer you soon that specifically has done Hayes. my brakes are just like cars or motorcycles...not sure if yours are.

generally,
1)you gently squeeze your lever 2)then crack the valve on the caliper 3)observe the fluid coming out 4)snug the valve closed again 5)release the lever 6)repeat
(incidently, this will work on your car as well. rather than sqeezing your lever, you'll press your pedal. start with the furthest caliper from your master cylinder in the engine bay...i.e. right rear, left rear, right front, and left front)

make sure master cylinder does not run dry

couple tips:

use closed end wrench on bleeder valve

put a loop in the tubing so that fluid has to go "up hill" and you will minimize any retrograde air

mvonb

If you had a garage, I wouldn't let you service my car brakes. How do you ensure that the fluid doesn't overspill the master cylinder? And what about the clearance of the pistons if they are not fully retracted when bleeding, or contaminating the brake pads with spilt fluid. Never, ever mix brake fluids, and always remove the wheel and brake pads. Simple rule, unless you want to lose all brake effectiveness.

Hank Rearden

Hope doesn't recommend DOT3.

Hope doesn't recommend mixing DOT4 and DOT 5.1. In fact, they specifically recommend purging the sytem of older fluid if it has a different DOT rating.

mx_599

that's cool....i don't have time right now. only time for my SSBC Force 10 calipers and 13" rotors.

steady hand?

i don't know what to say? what are you talking about silly?

from the way you're talking, i wouldn't let you work on my stuff either!

i don't wear the fluid! for christ sakes, if you are that messy than by all means get some painter's plastic and drop cloths and secure the whole area.

rarely, if ever, do i spill even a drop while pouring into the tiny MC on bicycles...autos are even easier.

maybe the bottles you pour from are messy and dribble like crazy or maybe you have a neurological problem, i don't know

why? they're miscible

mx_599

that's cool....if hope told me to jump off a bridge before breaking in their brakes i wouldn't necessarily do it. you don't always have to be a follower. if someone is riding XC and high temps aren't a major issue than why would DOT 3 be so bad? the DOT fluids i mentioned are all miscible with each other...no sludge would occur. not really a major issue.

personally i use Motul 5.1 and i purged my system

mvonb

I would just like to know how you could efficiently add the fluid to the master cylinder from a standard sized container and ensure none of the fluid overflowed or spillled. Don't forget not everyone nows that brake fluid is agressive to paintwork and seals.

mx_599

okay...a syringe is cool. my point was that hopes are nice because you DO NOT need the special bleed kit like some other brands and you definitely do not need to remove the caliper or perch from the bike. all you really need is a couple feet tubing with a loop in it and usually an 8mm closed end wrench.

to answer your question, i must have better pouring skills than you

mvonb

With you on the coiled hose and the closed end wrench, and I have been running Hopes for abround 4 years now. I am biased, since they are made about 50 miles from my family's home.

mx_599

not trying to be a jerk, but i am having a hard time following you?

mvonb

Maybe that's because I am English. What I mean is, you are correct about the coiled hose stopping air entering the system.

mx_599

Riles

Hey guys, between the pissing contest excellent advice there - I appreciate it...

I will stick with DOT 5.1, can get it pretty easy, will stick a loop in the hose - the process looks easy - thanks..

MX599 - flavour of the month now looking for good for April - could we go for Jenna Jameson and some friends in May ? (I think I maybe getting forums mixed up....sorry...)

mx_599

you guys

you can make me an avatar if you'd like. just keep it within the forum guidelines

snoopz666

dot 5.1 is not silicon based it is glycol-ether based like dot 3 and 4. they are all mixable. oh and bleed them theyre the easiest brake on the market to bleed.

mx_599

+++++1