Tight front brake

[ultimax]

Hi!

 

Can the front brake be adjusted? The front wheel doesn't spin freely when its jacked up. It's like the caliper's gripping the brake disc. It doesn't even complete 1/2 a rotation when i use a considerable amount of strength to spin it!

 

I've bled the brakes completely but to no avail. Thought the brakes would wear loose after a while but it's been a weak and the problem's still there. I'm afraid the additional friction will increase fuel consumption and cause other problems.

 

Any idea what's going on?

 

Thanks!

[Guest motofreak]

1) With a help of a fren, just wobble the front tyres. See and feel if there is too much leeway and keep a sharp hearing for grinding sounds when u wobble or spin it.

 

2) Check the brake discs, it mite have been warped or so.

 

3) Check for anything stuck or obstructions between the tyres and the fender. Sometims may not realise it that the fender has been touching it all a long. Look for bumps on the tyres at the same time.

 

4) If all else fails, brint it to Planet and let the racer with the Pokkadot helmet test ride it. U may be surprise wat else he may find out just by riding it.

 

Good luck bro!

[ultimax]

hey bro, thanks for your advice but I've solved the problem.

 

The pistons in the brake caliper had apparently gone too far out. I think that happened when my hands were itchy and I squeezed the brake lever while the calipers were off the disc. So the 2 bads were pushed closer to each other than they should be, hence the tight grip on the disc.

 

I took the brake caliper off, drained it completely, and with a hammer, hammered one brake pad down (was actually pushing the piston back into the caliper) so the gap between them was much bigger. Problem solved, and the front brake works fine now!

[wind chaser]

i have exaclty the same problem with my front wheel but i don't know how to DIY and solve the problem. i guess i must bring it to the bike shop. any other suggestion?

[Terrible One]

Hi wind chaser, u can try Ultimax suggestion and see if u still have the same problem. Could be ur wheel bearing also, if worn or damaged can cause ur wheel to be out of alignment thus the rubbing of ur brakes

[wind chaser]

i just changed my tyres so I don't think my bearings are worn out;otherwise my mechanic would have detected right?

[Tourer]

Well not really. Sometimes the mechanic who changed your tyres don't really care.

[Bluetooth]

First possible cause : brake piston in calipers cannot retract when there is no positive pressure into the caliper.

 

Need to do a complete brake caliper overhaul by diassembling caliper and change caliper pistons and seals.

 

Check also the wheel hub bearings, are the bearings able to rotate smoothly and on spinning the front wheel, what is the run-out of the rim? That is, does the front wheel wobble or is drifting from left to right as it's spins by more than 3mm or more?

 

If there is significant run-out then you need to replace bearings in hub.

[d0n]

i believe this problem will also exist when a new brake disc or brake pads are replaced right??

in this case the rubbing issue is not considered a problem i guess?

[wind chaser]

my wheel bearings are are worn out cos there is no wobble. my dics and brake pads are not new too. could be calipers

[kaozie]

most of the time its the brake dust that is trap on the pistons causing the pistons unable to return when the brake lever is release...

get some de-greaser and clean the pistons will do...

[wind chaser]

is there any way to clean the pistons without taking them out?

[d0n]

Originally posted by wind chaser@January 12, 2007 11:38 pm

is there any way to clean the pistons without taking them out?

'them' refers to the pistons or to the entire caliper as a whole?

 

caliper is cfm muz take out before u can get close to the other parts e.g. pistons, brake pad

 

it depends on whether if u wan to dismantle the whole thing and take out the pistons to clean OR u r okie with simply wiping/cleaning the part of the piston that is exposed/not retracted

 

[wind chaser]

how to clean with taking out anything?

[kaozie]

Originally posted by wind chaser@January 14, 2007 01:06 am

how to clean with taking out anything?

use engine de-greaser and spray directly on to your brake pistonthrough the small gap between the capilar and pads...

[Raptor]

Originally posted by wind chaser@January 10, 2007 02:01 pm

i just changed my tyres so I don't think my bearings are worn out;otherwise my mechanic would have detected right?

There is your answer.

 

The mechanic must have overtightened the axle nut when fitting back your front wheel.

 

Overtightening of the axle nut will put alot of pressure on the front wheel bearings... not only causing them to bind which result in a front wheel that does not spin freely but also causing them to heat up and melt whatever lubricating grease within.

 

Jack up your front wheel again and loosen the axle nut abit. Am sure your front wheel will spin freely.

[wind chaser]

axle nut? wat if i loosen too much and i don't tighten it enough? my wheel might come off on the expressway. a scary thought but thanks for the suggestion. i think i better bring it to the shop

[Raptor]

Originally posted by wind chaser@January 14, 2007 11:25 pm

axle nut? wat if i loosen too much and i don't tighten it enough? my wheel might come off on the expressway. a scary thought but thanks for the suggestion. i think i better bring it to the shop

Please lah... its not that easy for the wheel to come off unless you loosen the axle nut fork clamp bolts and pull the axle shaft completely out.

[wind chaser]

haha! guess wat, i realise i don't have the tool to do tat anyway. i tot i can use my friend's car tool but not compatible. sian. really have to go to southern motor now. hope the mechanic won't say things like ' ah ya, learn to do it yourself mah.'

[wind chaser]

just came back from southern motor. ah heng adjusted the nut a bit. said my brake pads about to run out so caliper very out. so wheel a bit tight. wat u think?

[Raptor]

Originally posted by wind chaser@January 15, 2007 12:32 pm

just came back from southern motor. ah heng adjusted the nut a bit. said my brake pads about to run out so caliper very out. so wheel a bit tight. wat u think?

He is probably right.

 

I would also recommend that he clean out the brake caliper pistons (the ones that push against the brake pads when you brake).

 

They are probably heavily coated in brake dust and grime and therefore are restricted when they try to retract when you release the brakes.

 

This will result in the brakes 'grabbing'.

[allenkey]

it could be that brake fluid is low, check the level indicator. when brake fluid is low, the 'spring-effect' is lessen.

[kaozie]

Originally posted by allen key@January 23, 2007 04:02 am

it could be that brake fluid is low, check the level indicator. when brake fluid is low, the 'spring-effect' is lessen.

if the brake fluid is low, air would have gone into the brake lines causing sponginess to your brake.

over-tightening of the axle will never cause the wheel to be tight as the bearings have been pre-loaded at the factory to ensure that bearings will not be over tighten and allow free-play for bearing expansion.

[Raptor]

Originally posted by kaozie@January 23, 2007 08:09 pm

if the brake fluid is low, air would have gone into the brake lines causing sponginess to your brake.

over-tightening of the axle will never cause the wheel to be tight as the bearings have been pre-loaded at the factory to ensure that bearings will not be over tighten and allow free-play for bearing expansion.

Next time when you get a chance to ovetighten the front axle nut.. try it and you will understand what I mean.

[kaozie]

Originally posted by Raptor@January 26, 2007 07:35 pm

Next time when you get a chance to ovetighten the front axle nut.. try it and you will understand what I mean.

i have too many chances to over-tighten everything liao... if you are able to tighten your wheels till it can't spin, then you might have a problem with the bearing pre-load...

anyway, every single bolts/nuts have a specific torque to be tighten to. over-tightening it will only cause damage to your bolts/nuts or to the threads...