Calliper lockup

[a2zworks]

Hi all,
Yesterday while riding the left calliper locked up on my 2000 R1150GS no ABS Brembo brakes.
Frightened the crap out of me and nearly was collected from behind by the lady driver.

I managed to pull the calliper off and pushed the pistons in, tried the front brake again but this time the pistons were stuck in with the right calliper working fine.
When I got home had a quick look and pistons still stuck in, pulled brake lever really hard and could feel stuck pistons moving out and got stuck locking the disk again and not returning.

Today I pulled the callipers off and apart, pistons, cylinders and seals are in good condition.
Cleaned, reassembled and reinstalled both callipers along with all new DOT 4 brake fluid.

Once again left calliper locked up on disc with right side working fine.
I am at a loss as to what could be causing this, any ideas anyone?

Thanks in advance.

 

[Beebop]

Check that the hoses havent collapsed inside forming a one way valve.

 

[Old Codger]

Sounds like

Hose failure internal collapse

If you are lucky with the brake lever held on hard you may be able to see the guilty hose expanding and ballooning

Happened on my 1100 but just caused drag not lockup

May be wise to invest in a set of stainless steel lines I used Goodridge

Good luck

 

[a2zworks]

Yes my friends you are both correct, well done and thanks.
New lines all round ordered.

Pablo

 

[Old Codger]

Hi

Glad you are sorted Pablo

 

[Ferretboy]

Hi all,
Yesterday while riding the left calliper locked up on my 2000 R1150GS no ABS Brembo brakes.
Frightened the crap out of me and nearly was collected from behind by the lady driver.

I managed to pull the calliper off and pushed the pistons in, tried the front brake again but this time the pistons were stuck in with the right calliper working fine.
When I got home had a quick look and pistons still stuck in, pulled brake lever really hard and could feel stuck pistons moving out and got stuck locking the disk again and not returning.

Today I pulled the callipers off and apart, pistons, cylinders and seals are in good condition.
Cleaned, reassembled and reinstalled both callipers along with all new DOT 4 brake fluid.

Once again left calliper locked up on disc with right side working fine.
I am at a loss as to what could be causing this, any ideas anyone?

Thanks in advance.

Glad you survived your lock up! I wasn't so lucky on a Yamaha xtz 750 last year, I just had bought the bike the day before my accident , the front brake lever was incorrectly adjusted , not allowing the fluid to return into the master cylinder, I had a lock up on a roundabout , no brake applied , I broke my arm , dislocated my shoulder , 2 operations later I'm good as gold !
It's violent and sudden , wouldn't wish it on anyone

 

[a2zworks]

Far out Ferretboy, glad to hear that you have recovered. The car behind me just missed me, only just left a white scuff mark on my rear guard as she swerved around me.