Jammed Rear Ultegra Brake

[Rooster1]

Hi

My rather high mileage and abused rear brake now refuses to spring back open - a common issue I know and one I have faced and sorted many times.

Last weekend I managed to fix the same issue on a Tiagra brake by releasing the right hand bolt a little.

But with the Ultegra brake I have, the allen hole is smaller and more fiddly and was full of gunge. The allen key does not turn the screw - it just wears down the inside of the bolt.

I have lubricated all the joints and pivots etc but it ain't springing open sooooo.......

I have left the whole thing in motor oil overnight to see if that helps!

There is a bolt on the reverse side aswell which I have also tried with an allen key.

I know I can sort it, but it is being a real PITA

 

[User6179]

Have you ruled out a sticky cable? I changed my Ultegra rear caliper after 40000 miles only to find out it was the cable sticking.

 

[Rooster1]

Have you ruled out a sticky cable? I changed my Ultegra rear caliper after 40000 miles only to find out it was the cable sticking.

The brake is off the bike and cable free - it's still not springing back. But thanks for reply

 

[User6179]

The brake is off the bike and cable free - it's still not springing back. But thanks for reply

I think the metal spring gets weaker over time then any muck between the pivot stops it opening.

If you look at the back of the caliper the spring goes into a square bit of plastic, the hole the spring goes into is offset so if you swivel the bit of plastic around it effectively puts more tension in the spring.

It is a bit of a fiddle but if you open up the caliper to reduce tension then use a flat bladed screwdriver above the plastic part you can unhook the spring.

 

[Ajax Bay]

I think the metal spring gets weaker over time then any muck between the pivot stops it opening.

"I think the metal spring gets weaker over time" Not this.
"muck between the pivot stops it opening" This.
Cleaning as best one can is the way ahead, as the OP is trying.

 

[gazza1286]

You need to dismantle the caliper and re-grease. This video explains how:

View: https://youtu.be/TqbCR83psAg

 

[fossyant]

I think the metal spring gets weaker over time then any muck between the pivot stops it opening.

If you look at the back of the caliper the spring goes into a square bit of plastic, the hole the spring goes into is offset so if you swivel the bit of plastic around it effectively puts more tension in the spring.

It is a bit of a fiddle but if you open up the caliper to reduce tension then use a flat bladed screwdriver above the plastic part you can unhook the spring.

Bike abuser !!! I have 30 year old Shimano 600 callipers that still work, and similar age Dura Ace ones.

 

[User6179]

Bike abuser !!! I have 30 year old Shimano 600 callipers that still work, and similar age Dura Ace ones.

My caliper had been used for over 40000 miles, front one still going strong with zero maintenance.

 

[Smokin Joe]

My caliper had been used for over 40000 miles, front one still going strong with zero maintenance.

There's just no stopping you, is there?

 

[User6179]

There's just no stopping you, is there?

????

 

[Smokin Joe]

????

Sorry, should have put a smiley.

 

[Rooster1]

IT'S FIXED !!!! The oil bath has freed the caliper up nicely! Result.

 

[Rooster1]

Have you ruled out a sticky cable? I changed my Ultegra rear caliper after 40000 miles only to find out it was the cable sticking.

Is that all seasons ?

Mine are on about 12,000 miles (all conditions)

 

[User6179]

Is that all seasons ?

Mine are on about 12,000 miles (all conditions)

May until October usually every year until last year where I have ran the bike through winter for the first time.