Re: Brake bleeding problem
 

They won't work if there is air trapped at a high point like a banjo bolt in this case.

And no reason a brake bleeding kit is any more safe.

Re: Brake bleeding problem
 

Where are you based Mack. More than happy to help if reasonably local

The bit you point to isnt going to be a rpoblem, its just a dust seal for the piston in the MC.

Re: Brake bleeding problem
 

Interesting. I've done the lever tying thing a few times and it's seemed to work, although I couldn't work out any reason why it should.

Re: Brake bleeding problem
 

There's the theory that
"it allows air to move to the reservoir" which is obviously bollox as the res is cut off when the lever's back.
There's another one which says it makes the air dissolve into the fluid (uniformly), then when you release pressure it will come out of solution, but the bubbles will hopefully go somewhere where they can be removed.

What I think happens is them being sat with pistons extended a bit lets the seals creep a bit and this is what makes the bite point earlier and nothing to do with air.

Re: Brake bleeding problem
 

YC you say that a brake bleeding kit is no more safe than a spanner on nipples or joints but the OP was asking about what seems to be a cover,if it would affect the bleeding process so I presume lack of knowledge?. Not everybody has full mechanical knowledge and at least with a kit or tube in a jar you don't have any air feeding back.I was not trying to belittle anybody and all the advice given is good,just erring on the side of safety if performing the process single handed.How a hyraulic system works in theory isn't always how it operates in practice especially if airpacks are concerned or you have to keep locking the system before you can get 100% movement of the hydraulic fluid from resevoir to the air/bleed outlet resulting in trapped air moving back and forth within the system.
It is a lot easier to be standing up topping up the resevoir and operating the brake lever with the caliper nipple open and fed into a bottom resevoir so that air does not feed back than to be pumping the brake lever and locking off nipples and banjos and topping up at the same time.

Re: Brake bleeding problem
 

With bleeder you need near perfect air tight joints or air draws back in. Lack of knowledge or not you need to know the same things whether you add extra kit or not!

I am not saying bleeder is wrong choice, just that it has no safety benefits. Simply... if the lever is hard, good job, it is as safe as it is going to get.*



*Unless you forgot to bolt calipers on, in which case exact method of bleeding is completely disconnected from safety.

Re: Brake bleeding problem
 

Yes agreed but I would presume somebody with basic knowledge would comprehend that rather than put their life in peril.