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-   -   How badly have I cooked my brakes? (http://www.biker.ie/forum/showthread.php?t=244135)

CodeJACK 13th June 2018 10:53 AM

How badly have I cooked my brakes?
 
Fitted new hoses to the Z yesterday and everything seemed fine. No air left coming out of the nipple and firm to the touch. Took it for a brief test spin and all seemed great.
This morning, the lever felt a little soft but firmed up after a few pumps. On the way to work on the M50, I felt a lot of drag on the front and lever was rock hard when trying to pull it. front felt like it wanted to lock up. I shit my pants and slowed down :doh:

Shortly after, I lost front brake all together. Nothing. It firmed back up a little the more I pumped but fluid level is still the same in the reservoir.
When I got to work, Its clear from the front disks that things got toasty. Burn mark is pretty obvious.

So I clearly missed an air bubble or something else? Its the ABS model but there shouldn't be any diff when bleeding, right? Rear brake is grand and although they use the same ABS pump, I think they are actually not linked??

Valiant Thor 13th June 2018 12:07 PM

Re: How badly have I cooked my brakes?
 
take off the caliper and see if its the calipers your thinking, hopefully its not but for the master cylinder you can get a rebuild kit from wemoto for small enough money

DavyH 13th June 2018 12:36 PM

Re: How badly have I cooked my brakes?
 
There's air trapped in the system, did you get an abs warning light?

The brakes are not linked on them by the way

manbearpig 13th June 2018 12:42 PM

Re: How badly have I cooked my brakes?
 
Bring it to a mechanic - no point messing around with it at work. Dont go home with the brakes binding

nednedned 13th June 2018 12:45 PM

Re: How badly have I cooked my brakes?
 
will need to replace the brake fluid as it was cooked. As mentioned above i wouldn't really drive it.

CodeJACK 13th June 2018 01:29 PM

Re: How badly have I cooked my brakes?
 
I see no leaks anywhere but I'll go out to the bike shortly and check again. I understand the thought of bringing it to mech but I'll try another bleed again to make sure its not just that.
I just wanted to check with those that might have experienced this before, that I have not done any permanent damage to the system.

manbearpig 13th June 2018 03:44 PM

Re: How badly have I cooked my brakes?
 
[quote=CodeJACK;3541538]I see no leaks anywhere but I'll go out to the bike shortly and check again. I understand the thought of bringing it to mech but I'll try another bleed again to make sure its not just that.
I just wanted to check with those that might have experienced this before, that I have not done any permanent damage to the system.[/quote]

You might have gotten away with permanent damage but cannot say without looking at the bike.

Possible that the disks have warped and most likely that your brake pads are glazed. . . feel for pulsing through the lever as you apply the brakes and have a close look at the pads.

CodeJACK 13th June 2018 03:49 PM

Re: How badly have I cooked my brakes?
 
Yeah, think I got away with it. Brakes apear to be fine except for the visual scorching on the disks. Pads on there are the old pads and I've new pending to be fitted once I get this sorted.
Seems a little off that they have free'd up by themselves but I can only assume that whatever air was trapped, has somehow found its way to the reservoir.

me2 13th June 2018 04:03 PM

Re: How badly have I cooked my brakes?
 
Spongy lever is usually air in the system, can also be bad // contaminated fluid.

Brakes locking can be the calipers need cleaning, ya might do it anyway now.

If I'd driven any distance with binding brakes, I'd get shot of the pads regardless, personally I'd not trust them.

CodeJACK 13th June 2018 06:07 PM

Re: How badly have I cooked my brakes?
 
Same happened again on the way home but I pulled in this time. Lever was rock hard so I pumped it a good few times and it free'd up and was then grand all the way home. Back to bleeding I guess.
As it turns out, HEL shipped a wrong banjo fitted to one side of the fork that they are going to replace for me, so I'll need to do the full job again anyway.

allsorts&oddjobs 13th June 2018 06:23 PM

Re: How badly have I cooked my brakes?
 
Sounds like the brakes are locking on cos fluid cant get back to the reservoir for some reason, hence the rock hard lever, go through the whole thing again looking for blockages.

If it was just air in the system the brakes would be spongy and the lever coming too far back to the bar, thats not your problem.

allsorts&oddjobs 13th June 2018 06:24 PM

Re: How badly have I cooked my brakes?
 
That wrong banjo would be a prime suspect.

fabiostar 13th June 2018 09:30 PM

Re: How badly have I cooked my brakes?
 
check the little relief valve hole in the master hasnt been blocked. they are tiny holes and allow the back pressure to blow off back into the master..

fran 13th June 2018 11:08 PM

Re: How badly have I cooked my brakes?
 
Tie the brake lever back as tight as you can get it with a bungee cord and leave over night. This has worked many times to release any air in the system. No point in tying with a rope etc you need the sponginess of the bungee cord to keep tight pressure on the lever all night. HTW

allsorts&oddjobs 14th June 2018 12:37 AM

Re: How badly have I cooked my brakes?
 
[quote=fran;3541659]Tie the brake lever back as tight as you can get it with a bungee cord and leave over night. This has worked many times to release any air in the system. No point in tying with a rope etc you need the sponginess of the bungee cord to keep tight pressure on the lever all night. HTW[/quote]

Air in the system is not the problem.

CodeJACK 14th June 2018 01:38 AM

Re: How badly have I cooked my brakes?
 
[quote=fran;3541659]Tie the brake lever back as tight as you can get it with a bungee cord and leave over night. This has worked many times to release any air in the system. No point in tying with a rope etc you need the sponginess of the bungee cord to keep tight pressure on the lever all night. HTW[/quote]

No harm trying that. Have a bunjee wrapped tight around it now and holding the level to the bar.

me2 14th June 2018 01:51 AM

Re: How badly have I cooked my brakes?
 
[quote=allsorts&oddjobs;3541669]Air in the system is not the problem.[/quote]It would account for the initial softness and the need to pump it up to pressure. I'd have no doubt about about the problem being with the lines, but that also begs the question of how he managed to successfully bleed the air out in the first place. Another possibility is dot 3 and 4 are both hydroscopic, can the op be sure he used fresh shit? My my money is still on road crud locking the piston when he applies the brake, as the first issue. The lever going from too some to too hard is a second issue.

Vjmc.Cork 14th June 2018 08:21 AM

Re: How badly have I cooked my brakes?
 
Sounds like the reservoir is over full

CodeJACK 14th June 2018 01:07 PM

Re: How badly have I cooked my brakes?
 
[quote=allsorts&oddjobs;3541669]Air in the system is not the problem.[/quote]

Actaully, this seems to have helped so I'm almost certain that the issue is trapped air related. No binding on the way to work this morning and the level feels like there is good engagement. Still a little spongy.

I'll wait for HEL to send out the new host and do a full bleed again. I hadn't the bike on a stand during the bleed so I must have let air in via the reservoir when it got too low. I have a vacuum bleeder that I've used a lot without issue but I clearly made a mistake here and Im lucky there is no damage done. Disks do not seem to be warped and pads I don't care about as I've new ones to go on.

allsorts&oddjobs 14th June 2018 02:38 PM

Re: How badly have I cooked my brakes?
 
[quote=CodeJACK;3541735]Actaully, this seems to have helped so I'm almost certain that the issue is trapped air related. No binding on the way to work this morning and the level feels like there is good engagement. Still a little spongy.

I'll wait for HEL to send out the new host and do a full bleed again. I hadn't the bike on a stand during the bleed so I must have let air in via the reservoir when it got too low. I have a vacuum bleeder that I've used a lot without issue but I clearly made a mistake here and Im lucky there is no damage done. Disks do not seem to be warped and pads I don't care about as I've new ones to go on.[/quote]

Ok i stand corrected, dunno how air locked up the brakes tho.


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