Brake Lines

[fzinla]

Hello,

I just changed my rear brake line (doing the front next) but the kit that I used did not come with crush washers. So right now I do not have crush washers between the banjo bolt / banjo fitting / master cylinder nor between the banjo bolt / banjo fitting / rear caliper.

I do not see any leaks and the brake works fine... great actually.

My questions is: Should I redo the back brake line by adding the crush washers or just leave as is?

 

Thank you.

[DewMan]

Yes, I highly suggest the use of crush washers.

[sorkyah]

Yes, crush washers are a must on hydraulics. 

There may not be leaks atm but in a few hundred miles when you can't stop because a pinhole has been squirting your brakee fluid all over the street 

Not a good time to notice there's a problem

 

Napa auto parts, the washers are like $0.30 or something like that

And if you bring in the bolts they'll probably even help you match em

[fzinla]

Thank you for the recommendations. I went to Napa auto and was able to get the crush washer that are needed.

They only had copper crush washers, is that okay or do they have to be Aluminum?

 

Thanks again.

 

[topazsparrow]

18 minutes ago, fzinla said:

Thank you for the recommendations. I went to Napa auto and was able to get the crush washer that are needed.

They only had copper crush washers, is that okay or do they have to be Aluminum?

 

Thanks again.

 

Mine were all copper - they came with my kit (core). Holding steady after 1.5 years.

[fzinla]

Awesome. I will add them to the rear brake line tonight and put them to the front ones as well.

The kit that I got is the alternate version: it means that both front lines come directly out of the master cylinder rather than the left caliper feeding the right one.

I am not sure if there are any advantages or disadvantages with any of the two. Do you guys know?

 

Thanks again.

[mjh937]

@fzinla, the alternate version is easier to bleed as the line does not go up and over the fender.  You might get a little bit better feel, but I doubt it would be noticable (unless you did not bleed the stock version properly).  The stock setup is a bit neater as there are clips to hold the line in place, but as long as you like the look that is all that matters.  

 

Make sure you check that nothing is binding or pinching with the handlebars turned all the way in both directions. Also do not get brake fluid on plastic parts (it will squirt out if you sqeeze the brake lever with the cover off) I attached a photo of what can happen)

[r1limited]

Your crushing me Smalls

[fzinla]

Guys,

I installed the washers, the banjo fittings and the banjo bolt but the left caliper was leaking slowly. I kept tightening it little by little to stop the leak and the last time I tightened it I broke the banjo bolt. Why the leak? DO I need to buy new crush washers? What is the spec on the banjo bolt? Can I get a new one from auto parts zone? What torque should I torque it to using a torque wrench?

Sorry for all the questions but I am freaking out.

 

Thank you.

[Beemer]

Does the owners manual say anything about that job? Did you get an owners manual?

[fzinla]

No it does not.

I might just put the original bolt back on with new crush washers and make sure the surfaces are nice and smooth.

Do you happen to know the torque value for the banjo bolts? I could not find anything.

 

Thank you.

[rick]

this will help get you in the ballpark http://www.hoseandfittings.com/banjo-torque/

 

 

[mjh937]

@fzinla, the service manual says the torque should be 22 ft-lbs. 

[fzinla]

Awesome. Thank you.

There is a little play between the ID of the washer and the OD at the base of the Banjo Bolt; is that okay? Does the washer need to have an ID that fits snugly to the base of the bolt? Currently there is about 1/8" to 1/4" play.

 

Thanks again.

[topazsparrow]

3 hours ago, fzinla said:

Awesome. Thank you.

There is a little play between the ID of the washer and the OD at the base of the Banjo Bolt; is that okay? Does the washer need to have an ID that fits snugly to the base of the bolt? Currently there is about 1/8" to 1/4" play.

 

Thanks again.

ID play is okay. The mating surfaces are the broad sides... 1/4" seems like a lot though.

[sorkyah]

7 hours ago, fzinla said:

Awesome. Thank you.

There is a little play between the ID of the washer and the OD at the base of the Banjo Bolt; is that okay? Does the washer need to have an ID that fits snugly to the base of the bolt? Currently there is about 1/8" to 1/4" play.

 

Thanks again.

the bolt technically doesnt matter, 

as @topazsparrow stated the mating surfaces are the broad sides or the head of the bolt, the OD faces of the fitting. 

that should be fairly good. 

1/4" is a bit much, but if you can find ones that fits closer to size of the bolt shank dia, peace of mind may be found?

[rick]

I agree, 1/4" of gap is too much and likely why it leaked with the washers and not w/o. You lost a lot of surface area. 

 

I own a drawer full of torque wrenches and can't ever remember using on a banjo bolt. That you broke the 1st bolt trying to get the crush washers to not leak also says the washers you bought are wrong. 

 

Find ones that fit the bolt better. If the outer diameter is too big, that's not a problem as long as there's room. 

[fzinla]

Did the install and I do not see any leaks.

Thank you all.

 

I read somewhere that I can use a zip tie to keep the front brake pushed in overnight almost all the way to remove any tiny air bubbles that are left. I did do that the first time and that is what created the leak in both front calipers and the master cylinder. Should I do that again?

[shinyribs]

Tying the lever down won't bleed anything. I'm not sure how that myth got started. With the lever tied down no fluid can retract in to the reservoir, which means that no air can either. 

 

The brake system should also be able to hold full pressure at all times. If holding it activated for a long period of time showed a leak- it just showed the leak, it didn't create it. JMO.

[rick]

I think the theory is that the pressure causes the bubbles to get smaller and with time (overnight being the magical time needed) they give up their hold on the inside of the hose. 

Yeah, pretty much nonsense, imo as well. 

 

If the lever can be pulled all the way back, there's either a lot of air in the system or you put one monstrous squeeze on the lever. These bikes just aren't old enough for caliper seals to fail - due to natural causes. 

 

Remove the calipers one at a time and do a back bleed by pushing the pads back as far as the'll go. This pushes fluid (and bubbles) uphill into the master. 

[strider]

It may sound like nonsense, but it does work.

If you try it, you can often see a stream of tiny bubbles rizing to the surface in the master cylinder, and in the morning, the brake action will be distinctly firmer.

[Beemer]

I thought they made pumps for clearing brake lines of air.

[rick]

Like shiny ribs said, with the piston activated, any route for air to get out of the line is blocked by the piston. 

 

Maybe with some bubbles will rise to the top and when you release the lever they'll re-enter the master. 

 

If you have an air bubble caught in that loop of hose that goes over top the front fender - you can squeeze that lever so hard you pop knuckles out of joint and that won't change a thing.

 

Once all the air is out, you can just use gravity to replace the old fluid - no need to pump in either direction, no need to do anything beyond keeping an eye on the fluid level and make sure it doesn't run dry below the piston.

 

Hydraulic clutches can be notorious to bleed all the air out if you change lines or a seal. The last air bubble will get stuck right at the banjo fitting at the master - especially with a sport oriented bar that puts the banjo uphill to the master. The best solution is to either tip the bike to the right giving the bubble an uphill exit route into the master (something that can get noisy and expensive with a 500+ lb motorcycle) or install a bleeder valve at that top banjo - something my Aprilia has. 

 

 if a motorcycle shop told me they had to keep a bike overnight to squeeze air from a brake system, well, I'd find another mechanic. Hard to be so bold as to say never, but I doubt you will ever find this squeeze procedure in a service manual. 

 

think I'd let this guy work on mine  http://www.randakksblog.com/brake-bleeding-tips/  note what he says about the magic cure.