Best method for bleeding front brake system?

[13aines]

Hi all,

So the Daytona has got a spongy front lever recently, I think it's pretty bad, but I don't think i've ever had a perfect lever though, so not sure how much better it should be to be honest

I've had it a year, and the fluid hasn't been changed during my ownership, in the last 5k miles - and I don't know when it was done before this. I'm thinking i'll drain the front system, fill with fresh fluid, and bleed well - as soon as possible. Will do the rear too but less concerned about this.

Whats the best method? I don't have an airline, so vacuum bleeder isn't an option.

Have read about using a one way aquarium valve, two lengths of tube, and a little fluid in the bottom of a catch bottle, but don't fancy putting yellow teflon tape on my bleed nipple threads, as i've seen suggested to prevent air getting past the threads.

Considering reverse filling the system with a syringe - BN, can you explain your method please?

Thanks,

Matt.

[13aines]

Thanks for the advice.

I didn't mean drain the system - I will just pull (or push) the old fluid through, and ensure I don't let the reservoir run low.

I've done it by hand the two man way a couple of times before and just found it a total ballache with some systems (my ZXR400 with new race lines straight from the MC in particular!) and still not getting a great result - a solid lever.

Have you got links to the hand vacuum bleeders you've used with good experiences?

I'm happy to spend a little bit to get something that makes bleeding quick, easy, and is very effective at getting all air out of the system - it's something I'll have for years to come.

[13aines]

Jonjo91 said:

I use a syringe and piece of tube.

ebay link

Don't drain the whole system, "inject" from the bottom up, starting with caliper furthest away from the MC.

Unscrew bleed nipple, syringe in new fluid, drain from brake fluid reservoir and repeat a few times per caliper.
Doesn't take much time and ensures there is no air being put into the system.

Worked fine on all my bikes, and recently a friends SRAD when putting a new MC on.

That looks good - certainly simple and cheap.

[13aines]

mpusch, my stepdad has something similar and while it's easier than without it's never worked that well for me really.

Obscene kindly offered to let me use his compressor and vacuum bleeder, so next weekend I'm going to try to get over his and get it done. Shouldn't take long with his kit!

Thanks for all the responses, looks like i'll reverse fill the system in the future, and if that isn't easy enough i'll buy a vacuum bleeder that doesn't require an air line.

In the meantime, is it worth cable tying the lever overnight? If so just squeeze bloody hard and tie, or just like fairly heaving breaking?

[13aines]

I know you can do it with less kit but in the past I've had awful difficulties getting a firm lever using traditional methods but then this has generally been after fitting new lines and starting with an empty system.

I'm going to obscenes gaff tomorrow to utilise his air line. I may as well

Next time I'll persevere with traditional methods or use a syringe.

Thanks all.

[13aines]

Well I did it this morning with Obscene, and his air line and vacuum bleeder. Blimey it was easy! Thanks Obscene.

Was astonished by the amount of air bubbles (more air than fluid!) when we initially started drawing through the fluid on the LHS caliper. We finished up with both calipers drawing some very small air bubbles close together and the master cylinder not too bad. After a couple of pumps using the traditional bleeding method the line was clear of air. Back was really easy, and feels much firmer actually, surprisingly very noticeable.

The front seems much more effective but the lever still doesn't feel as rock hard as my ancient old Diversion so I've cable tied the lever back for the night. Even if the lever still doesn't feel rock hard the fresh fluid and bleed has certainly made the brakes much more effective. Looking forward to trying them out properly on a dry day.