Stiff brakes.

[Blacky309]

I currently own a 2007 CRF150f and and the front brake is extremely stiff.

It feels as though there is too much hydraulic fluid so I let a little out. (being careful not to let any air in.) It worked for a minute than started to tighten up again.

I also took the brake apart and looked at the brake pads and they still had lots on them.

This is my first bike and I have only owned since the beginning of the summer so if anyone can tell me weather it is something simple and I'm being stupid or if I need to replace a certain part.

Thanks to anyone who can help!

Edited July 28, 2014 by Blacky309

[spaceboy]

It might be normal. I have a borrowed 03' 150F that the GF has been riding for the last couple weekends and it has a super stiff/hard lever pull. The system has been bled, pads and rotor face resurfaced and bedded in and it still seems the same. Brakes still seem to work fine but for the given amount of lever pull/resistance I would think it would have better stopping power for descents.

[YZF_MX_rider]

Imo i like a tight brake cable like that but its none of what you listed. It's the cable. You need to fix it to be a tad longer if you want more pull.

[spaceboy]

Imo i like a tight brake cable like that but its none of what you listed. It's the cable. You need to fix it to be a tad longer if you want more pull.

Its hydraulic, there is no cable(front brake) so I don't understand your statement. Please explain.

[YZF_MX_rider]

Its hydraulic, there is no cable(front brake) so I don't understand your statement. Please explain.

sorry i mean let out some hydraulic fluid. Not a TON but not just a little and see. For some reason I was thinking of the clutch cable... :retarded:

[spaceboy]

sorry i mean let out some hydraulic fluid. Not a TON but not just a little and see. For some reason I was thinking of the clutch cable... :retarded:

I like the lever feel and stiffness. Just seems like it should have a bit more braking power for the lever feel. I do realize that this is a lower performance/keep cost down type of bike though so it may never be what I'm expecting from it compared to my 450X.

[YZF_MX_rider]

I like the lever feel and stiffness. Just seems like it should have a bit more braking power for the lever feel. I do realize that this is a lower performance/keep cost down type of bike though so it may never be what I'm expecting from it compared to my 450X.

thats probably exactly why. I mean my 230 has great brakes but my yz250f has much better brakes.

[4strokeridertt]

It should brake as well as a 450. Pads absorb all kinds of foreign contaminants that affects braking. Also the caliper floats from side to side on pins which need to be lubed and smooth. Just because the pads have material on them does not mean they are still good.

Fresh stock pads and a little sand paper work on the rotor along with cleaning the pins and lubing the holes they move in will make a huge difference. The pins that the pads are held on by should also be perfectly smooth and clean. If they are worn or corroded they should be changed.

Take a good look at the caliper and you will understand that if it is bound up and not floating correctly only one pad will actually get good solid pressure and even then not 100 percent. When the caliper moves correctly the pads on both sides will contact the rotor nice and square.

Next you need to have new brake fluid flushed through the whole system. Brake fluid absorbs moisture which then corrodes the caliper bore. The pucks in the caliper then bind up.

A little good maintenance goes a long way.

[YZF_MX_rider]

It should brake as well as a 450. Pads absorb all kinds of foreign contaminants that affects braking. Also the caliper floats from side to side on pins which need to be lubed and smooth. Just because the pads have material on them does not mean they are still good.

Fresh stock pads and a little sand paper work on the rotor along with cleaning the pins and lubing the holes they move in will make a huge difference. The pins that the pads are held on by should also be perfectly smooth and clean. If they are worn or corroded they should be changed.

Take a good look at the caliper and you will understand that if it is bound up and not floating correctly only one pad will actually get good solid pressure and even then not 100 percent. When the caliper moves correctly the pads on both sides will contact the rotor nice and square.

Next you need to have new brake fluid flushed through the whole system. Brake fluid absorbs moisture which then corrodes the caliper bore. The pucks in the caliper then bind up.

A little good maintenance goes a long way.

I know what you mean, were fixing my mom's car brakes. She needs a new caliper because the inside pad is worn down so the metal is being worn down and the outside pad is almost brand new.

[Blacky309]

sorry i mean let out some hydraulic fluid. Not a TON but not just a little and see. For some reason I was thinking of the clutch cable... :retarded:

I already tried to let some out. After about 5 pulls of the lever it tightened up again.

I was told by someone else that there is an equalizer type thing that keeps it at the same level so that with the cold/heat expansion or contraction of the fluid it will not affect the stiffness of the brake.

[Blacky309]

It should brake as well as a 450. Pads absorb all kinds of foreign contaminants that affects braking. Also the caliper floats from side to side on pins which need to be lubed and smooth. Just because the pads have material on them does not mean they are still good.

Fresh stock pads and a little sand paper work on the rotor along with cleaning the pins and lubing the holes they move in will make a huge difference. The pins that the pads are held on by should also be perfectly smooth and clean. If they are worn or corroded they should be changed.

Take a good look at the caliper and you will understand that if it is bound up and not floating correctly only one pad will actually get good solid pressure and even then not 100 percent. When the caliper moves correctly the pads on both sides will contact the rotor nice and square.

Next you need to have new brake fluid flushed through the whole system. Brake fluid absorbs moisture which then corrodes the caliper bore. The pucks in the caliper then bind up.

A little good maintenance goes a long way.

Thanks. I just bought this bike at the beginning of the summer and am not sure how well the bike was taken care of before.

[Confederate]

Check the caliper slide pins. The caliper is supposed to self center over the rotor. If it can't center it is applying all the pressure to the piston side and not tightening on the other side. This can cause poor brake application. I usually clean then apply anti seize to them.

[Blacky309]

Check the caliper slide pins. The caliper is supposed to self center over the rotor. If it can't center it is applying all the pressure to the piston side and not tightening on the other side. This can cause poor brake application. I usually clean then apply anti seize to them.

I am defiantly going to try that. I will let you know how it goes. Thanks for the help.

[SteveThe Snakes]

Aside from what has been mentioned here the little pivot push point on the lever to the piston plunger could get a dab of grease. It makes it feel a little smoother.

 

You might also be a young guy so smaller hands will make the set up feel stiffer. Changing the master cylinder with a smaller piston would help but probably not worth the trouble.

 

What some people did in the past was workout squeezing a tennis ball to gain more endurance on the clutch and brake levers.

[Blacky309]

Aside from what has been mentioned here the little pivot push point on the lever to the piston plunger could get a dab of grease. It makes it feel a little smoother.

You might also be a young guy so smaller hands will make the set up feel stiffer. Changing the master cylinder with a smaller piston would help but probably not worth the trouble.

What some people did in the past was workout squeezing a tennis ball to gain more endurance on the clutch and brake levers.

Yea, I'm only 15 but my friend has same bike yet it is still at least twice as loose as mine.

[FishFreq]

Aside from what has been mentioned here the little pivot push point on the lever to the piston plunger could get a dab of grease. It makes it feel a little smoother.

...and lube the lever's pivot point bolt and where it rubs inside the perch. If you've done that and lubed the caliper mentioned earlier, it could be two more things:

1. The lever pivot bolt can be too tight. When u squeeze the lever, if the lever doesn't rebound freely, it's too tight. If the lever is rattling or flopping around (up and down, opposite the direction of pull) then it's too loose. That pivot bolt is designed to be adjustable with the lock nut on the bottom. Loosen the lock nut on bottom, adjust the bolt so that the lever is free but not rattling, then tighten the lock nut. I use blue Loctite (threadlocker 'glue' by Permatext) on the nut too, cuz they tend to vibrate loose. Aamof, make sure there even IS a lock nut on the lever pivot bolt!! The perch is threaded for the bolt so u can take out up and down slop, then the nut is to counter tighten the bolt in place.

2. If by stiff you mean that actual point that the brakes start actuating happens RIGHT when u pull the lever, then you may want to increase the 'free play'. The little tiny black bolt with lock nut right in between the bar and the lever - is what presses the piston of the master cylinder inside the lever perch on your bars. That make sense? It's personal preference: some like brakes to apply close to bar cuz small hands, some like very little free play.

Once again, blue Loctite will avoid losing the free play adjuster bolt/nut out on the trail, and you don't have to over tighten things cuz u know the threadlocker will set up and keep it tight. Don't use red Loctite, that's too strong, used blue.

Whew! Ok check it out and report back!

[FishFreq]

...btw, draining fluid does nothing to change 'stiffness'. Always keep fluid reservoir full. Air bubbles in your brake line will make the lever spongy (bad thing). A proper hydraulic system uses pure fluid and has all air bled out.

[Blacky309]

...and lube the lever's pivot point bolt and where it rubs inside the perch. If you've done that and lubed the caliper mentioned earlier, it could be two more things:

1. The lever pivot bolt can be too tight. When u squeeze the lever, if the lever doesn't rebound freely, it's too tight. If the lever is rattling or flopping around (up and down, opposite the direction of pull) then it's too loose. That pivot bolt is designed to be adjustable with the lock nut on the bottom. Loosen the lock nut on bottom, adjust the bolt so that the lever is free but not rattling, then tighten the lock nut. I use blue Loctite (threadlocker 'glue' by Permatext) on the nut too, cuz they tend to vibrate loose. Aamof, make sure there even IS a lock nut on the lever pivot bolt!! The perch is threaded for the bolt so u can take out up and down slop, then the nut is to counter tighten the bolt in place.

2. If by stiff you mean that actual point that the brakes start actuating happens RIGHT when u pull the lever, then you may want to increase the 'free play'. The little tiny black bolt with lock nut right in between the bar and the lever - is what presses the piston of the master cylinder inside the lever perch on your bars. That make sense? It's personal preference: some like brakes to apply close to bar cuz small hands, some like very little free play.

Once again, blue Loctite will avoid losing the free play adjuster bolt/nut out on the trail, and you don't have to over tighten things cuz u know the threadlocker will set up and keep it tight. Don't use red Loctite, that's too strong, used blue.

Whew! Ok check it out and report back!

Thanks for all the help.