Robzimbo
Active Member
- Joined
- Dec 4, 2016
- Messages
- 57
- Country Flag
Not sure where to post this - 'Brakes', 'Trip reports', 'pub chat'... but it happened to my 105 so I'll put it here, though I guess it could have happened to any vehicle.
I was up in Meru National Park a couple of weeks ago. I crossed a river, and soon after there was a scraping sound from the front left wheel. I stopped and had a look. Couldn't see anything. Didn't take the wheel off though. The scraping noise continued, on and off, for an hour or three, moving slowly through the Park, then out onto the road, and for a hundred kms or so after that. It didn't sound serious. Silly me.
After a while it stopped, and I pressed on for Nairobi. A hundred kms or so further down the road, the brake warning light came on. Then the brakes got softer. Then they stopped working altogether. No brake fluid.
I pulled into a garage, found a 'fundi' (local for roadside mechanic) who took the wheel off, and this is what he found ...
Somehow, a stone had got wedged into the wheel rim. Every time the wheel went round, it rubbed against the caliper. Just before it wore through the stone, or the stone got ejected, it rubbed through to the cavity where the cylinder sits, and sprang a leak. A tiny, slow leak, but every time I pressed the brake pedal some fluid leaked out. That much is clear.
But, what I don't understand is this; how did the stone get wedged in the rim? why didn't it get displaced the first time it hit the caliper? how could it move, while remaining wedged in place, so that it scraped away the metal of the caliper?
The tyre is a 16 x 285 - so almost exactly a meter in diameter. So circumference is 3.14 meters. So thats approx 320 rotations per kilometer. So over (approx) 200 kms, that's 64,000 rotations. Say it was only scraping half the time, that's 30,000 impacts on the caliper... Yes, I know. I really should have taken the wheel off to see what was going on.
But... how could it have stayed in place? What kind of stone would resist 30,000 impacts against metal, yet not be obvious on a cursory inspection? Did I have a bloody great diamond wedged in my wheel for 200 kms?
Hmmmm.
Anyway. A second hand caliper cost a hundred quid, more or less. New brake pads, fluid, labour... not a cheap mistake. But a very thorough teaching of a lesson that I should have learned long ago...
'if it's making a funny noise, don't keep driving and hope it goes away. Stop and find out what's going on.'
All the best,
Rob
Nairobi
I was up in Meru National Park a couple of weeks ago. I crossed a river, and soon after there was a scraping sound from the front left wheel. I stopped and had a look. Couldn't see anything. Didn't take the wheel off though. The scraping noise continued, on and off, for an hour or three, moving slowly through the Park, then out onto the road, and for a hundred kms or so after that. It didn't sound serious. Silly me.
After a while it stopped, and I pressed on for Nairobi. A hundred kms or so further down the road, the brake warning light came on. Then the brakes got softer. Then they stopped working altogether. No brake fluid.
I pulled into a garage, found a 'fundi' (local for roadside mechanic) who took the wheel off, and this is what he found ...
Somehow, a stone had got wedged into the wheel rim. Every time the wheel went round, it rubbed against the caliper. Just before it wore through the stone, or the stone got ejected, it rubbed through to the cavity where the cylinder sits, and sprang a leak. A tiny, slow leak, but every time I pressed the brake pedal some fluid leaked out. That much is clear.
But, what I don't understand is this; how did the stone get wedged in the rim? why didn't it get displaced the first time it hit the caliper? how could it move, while remaining wedged in place, so that it scraped away the metal of the caliper?
The tyre is a 16 x 285 - so almost exactly a meter in diameter. So circumference is 3.14 meters. So thats approx 320 rotations per kilometer. So over (approx) 200 kms, that's 64,000 rotations. Say it was only scraping half the time, that's 30,000 impacts on the caliper... Yes, I know. I really should have taken the wheel off to see what was going on.
But... how could it have stayed in place? What kind of stone would resist 30,000 impacts against metal, yet not be obvious on a cursory inspection? Did I have a bloody great diamond wedged in my wheel for 200 kms?
Hmmmm.
Anyway. A second hand caliper cost a hundred quid, more or less. New brake pads, fluid, labour... not a cheap mistake. But a very thorough teaching of a lesson that I should have learned long ago...
'if it's making a funny noise, don't keep driving and hope it goes away. Stop and find out what's going on.'
All the best,
Rob
Nairobi