Best method for bleeding front brake system?
Discussion
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.
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.
Firstly don't drain the system dry. Just run lots of new fluid through.
You can get hand operated vacuum bleeding kits which work well and this would be my advice.
You can also get one way bleed nipples which are pretty good.
Aquarium tubing isn't in my experience big enough.
One other thing is don't drop the fluid bottle before you start - the b
d will almost go fizzy and you'll have to abort for the day or buy a new bottle.
You can get hand operated vacuum bleeding kits which work well and this would be my advice.
You can also get one way bleed nipples which are pretty good.
Aquarium tubing isn't in my experience big enough.
One other thing is don't drop the fluid bottle before you start - the b
d will almost go fizzy and you'll have to abort for the day or buy a new bottle.trickywoo said:
Firstly don't drain the system dry. Just run lots of new fluid through.
This, and don't allow the reservoir to get low as you're pumping the new fluid through as you may suck a bit of air in.I've tried the reverse syringe method and it's worked, but go slowly in case an end pops off and you squirt a jet of fluid everywhere!
Edited by rich_b on Wednesday 25th March 15:42
Reverse filling, fill the syringe with the required brake fluid, put tube onto bleed nipple, take reservoir cap off, crack the bleed nipple by half a turn and then force the fluid up the system with the syringe, this basically forces air out of the top rather than bleeding it out of the bottom.
Empty the reservoir first by sucking it empty with the syringe.
Empty the reservoir first by sucking it empty with the syringe.
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.
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.
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.
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.
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.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.
Probably going to repeat what most people have already said here, but seeing as I just bled my Daytona's front brakes a week ago I'll post up what I used. Started with a spongy lever and ended up with it rock hard.
Very cheap one man bleeder kit. Costs around $10 or so, and gets the job done in 10 minutes or so, max. I'm sure there's vacuum bleeders that will do it faster, but it was cheap and it worked well enough to get the job done.
Bleed the front left caliper first. Attach the "nozzle" to the bleed screw, loosen the screw and squeeze the brake lever. I believe the idea of the kit is to be able to continually squeeze the lever without tightening the bleed screw up each time before letting go, however I still tighten it (probably unnecessarily) each time to prevent any bit of air returning anyways. Loosen screw > Squeeze lever > Tighten screw (just enough to prevent fluid from passing through) > Release lever
Do this until the brake reservoir gets close to where it drains to the brake line, then add the fresh fluid. As others have said, if you let the fluid get beneath it, you will introduce an air bubble to the system. If you do this on accident, it's not the end of the world, it just means you'll need to do a bit more bleeding to make sure that bubble gets through the system. Keep doing this until you see the fresh brake fluid coming out of the bleed screw. This should be pretty obvious if your brake fluid is old. The old stuff will be dark/orange or something similar and the new fluid will be close to clear.
Repeat for the front left caliper.
Last you'll want to bleed the master cylinder. Same process except you'll have a lot less fluid to pass through it since it's so close to the reservoir.
Make sure you tighten all your bleeder screws back to spec. Replace the reservoir cover and secure that screw.
Very cheap one man bleeder kit. Costs around $10 or so, and gets the job done in 10 minutes or so, max. I'm sure there's vacuum bleeders that will do it faster, but it was cheap and it worked well enough to get the job done.
Bleed the front left caliper first. Attach the "nozzle" to the bleed screw, loosen the screw and squeeze the brake lever. I believe the idea of the kit is to be able to continually squeeze the lever without tightening the bleed screw up each time before letting go, however I still tighten it (probably unnecessarily) each time to prevent any bit of air returning anyways. Loosen screw > Squeeze lever > Tighten screw (just enough to prevent fluid from passing through) > Release lever
Do this until the brake reservoir gets close to where it drains to the brake line, then add the fresh fluid. As others have said, if you let the fluid get beneath it, you will introduce an air bubble to the system. If you do this on accident, it's not the end of the world, it just means you'll need to do a bit more bleeding to make sure that bubble gets through the system. Keep doing this until you see the fresh brake fluid coming out of the bleed screw. This should be pretty obvious if your brake fluid is old. The old stuff will be dark/orange or something similar and the new fluid will be close to clear.
Repeat for the front left caliper.
Last you'll want to bleed the master cylinder. Same process except you'll have a lot less fluid to pass through it since it's so close to the reservoir.
Make sure you tighten all your bleeder screws back to spec. Replace the reservoir cover and secure that screw.
mckeann said:
Do you mind me having a st of this. If it's good I'll get one. Gassing Station | Biker Banter | Top of Page | What's New | My Stuff