Would boiling your brakes do any permanant damage?

[stinkwheel]

I mean full-on boiling, no pressure at the lever and fluid coming out of the master cylinder, not just fading slightly.

Got a little overenthusiastic checking that the brakes on the CB500 are indeed now working properly without pulsing (they are, and it'll lock the front wheel at 100mph).

I'm sure some of the trackday lot must have boiled their brakes to oblivion before.

They came back once it cooled down a bit but I'm a little concerned I may have cooked the seals.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Nexus Icon]

I've never done it on a bike but I have in cars a few times. It's never done any permanent damage that I can remember but I used to renew the brake fluid as soon as I practicably could. I've no idea if that's necessary, it just seemed like a good idea.
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Greetings from Shitsville!

[tatters]

Have done so on a VFR750 a few years ago thrashing it about the twistys, did,nt have any problems once the system had cooled down but was a bit scary having no front brakes when trying to slow down from 90mph.
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Past:NRG50,AF1125(x2),NSR125RR,ZZR250,CX500,VFR400,KR1S,ZZR600(x2),CB400N,YZF1000(x2),KH125,Z200,FX400R,CBR954RR(x2)GPZ500S,GT550,VFR750F(x2),RD350N,XR650R,CBR600F,CB250,KDX250,YZF750R,CRM250,400EXC,KLR650,TTR600RE,DR350S,R100GSPD,RGV250,VMAX1200,DL650,KZ750 Present:G650XC,C12,CRF450X,1190ADV

[Kickstart]

Hi

I wouldn't expect real damage, but I would be inclined to replace the fluid and check the disk and pad condition.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[weasley]

The main damage comes when you have boiled the brakes and are still going too fast to avoid the car/hedge/ditch.

Other than that I would say probably a temporary effect.
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Yamaha XJ600 | Yamaha YZF600R Thundercat | KTM 990 SMT | BMW F900XR TE

[stinkwheel]

Cheers guys. Put my mind at rest.

I'll take it out for a run tomorrow just to make sure everything is as it should be (and to take the nibs off the tyres..).
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[c_dug]

I thought that was an indication of water in the fluid?

If not surely chris-red would have boiled his fluid in his thread about burning his front disks last week?
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I am a bellend, I am a man of constant sorrow, I am a gummy bear, I am a rock.

[MarJay]

Stinkwheel I'm a little surprised in all honesty. I thought you were the 'Go-to-guy' in the Workshop area!

It won't have done any permanent damage, no. I would change the fluid though, because although it might not do any permanent damage to the braking system hardware, it might do something to the fluid that I'm not aware of. Its not supposed to boil after all. The fact that it boiled at all is probably indicative of something wrong with the fluid anyway.

Still, sounds like you sorted the brake pulsing. What was the problem in the end, out of interest?
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Kickstart]

[G]

I'd be looking to replace the fluid with some better fluid (less contaminated) maybe.
While I was at it, I'd be looking to replace the tyre with a good one too .

Never boiled the fluid including with racing and trackdays on road bikes; but believe it happens pretty often at car trackdays and never causes further problems.

[stinkwheel]

It was brand new DOT4 fluid from a sealed container put in on Saturday when I fitted the freshly rebuilt calliper, newly skimmed disc, braided steel hose and Armstrong HH pads.

Err. I think I did go rather over the top with the application of said brakes to be honest.

Three consecutive "bump and run" emergency stops from three figure speeds on my local "testing circuit". It was fine until I stopped at a junction waiting to turn right and brake fluid started pishing out of the master cylinder. Burned all the greasy fingermarks off the caliper anyway. Maybe I shgould get one of those sweat band things to go round the master cylinder.

I will admit, for a single 2-pot sliding calliper, the brakes are now rather good.

Oh, and it has a fairly new BT45 tyre on although it was possibly not fully warmed up at the first go.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Piercee100]

My old Capri used to boil its brake fluid every now and again, and noticed that its started to congeal into a jelly. I dont know how old this fluid was but changed it soon after.
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Rides: Honda H100a (Retired), VT500e (Sold), Kawasaki ZX400 (sold), Kawasaki GT550 (Sold), Suzuki Inazuma (Daily), Honda CD185t (Broken), LML Star 2t (Last run edition).

[0l0dom0l0]

I'd be careful, I cooked the rear brake on my Fazer at Donington recently. Full on boiling, no pressure on the lever what so ever.

I only overhauled it a few months ago, fully re-built with seals and pads etc.

One of the dust seals is now totally shot, and that piston won't move at all. It has clearly deformed from the heat so stuck itself on the piston.

HTH
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CBT Passed: 30/08/2009, Theory Passed: 31/08/2010, Mod 1 Passed: 6/9/2010, Mod 2 Passed: 13/09/2010. Restriction ended 13/09/2012.

Bikes: 2007 Derbi GPR 50, 1998 Yamaha Fazer 600 (written off), 2002 Yamaha Fazer 600, 1994 CBR 600F, 2003 Triumph Daytona 600, Kawasaki ZX6R J1.....Current: 2006 Yamaha FZ6, 1998 Suzuki TL1000R and a Honda VFR 400 NC30.

[G]

[chris-red]