Brake Fitting

[curzons246]

I'm building up a 531c frame - i'm fitting some Dura Ace BR-7402 single pivot SLR brakes. It appears that when I tighten up the Allen bolt to secure them to the frame it nips the caliper up ie the arms cant clamp and release? Is the boss that holds the caliper release spring threaded? Should I be able to undo the cone headed nut on the front? is the pivot bolt to short and can it be replaced - any guidance please
Cheers Bill

 

[mickle]

Weird.

 

[mickle]

Hve you got a washer betwixt brake and crown?

 

[RecordAceFromNew]

I'm building up a 531c frame - i'm fitting some Dura Ace BR-7402 single pivot SLR brakes. It appears that when I tighten up the Allen bolt to secure them to the frame it nips the caliper up ie the arms cant clamp and release? Is the boss that holds the caliper release spring threaded? Should I be able to undo the cone headed nut on the front? is the pivot bolt to short and can it be replaced - any guidance please
Cheers Bill

As it happens I have a set of br-7402 in front of me. The boss that holds the spring is in one piece with threading both front and back, and the calipers should be able to swing freely independent said boss based on the adjustment of the nut (10) at the front. As such I can't see why tightening the allen nut (in 1) at the back on to the frame would affect the caliper arms.

 

[accountantpete]

It sounds like the brakes are seized before you tighten up the hex nut - take them off and squeeze to see if they move freely.

If they are seized then you unscrew the domed nut and the locknut behind it. Then take the rest apart and give the area a good clean/re-grease and put together again tightening the locknut against the domed nut.

 

[curzons246]

Thank you both - i've applied loads of wd40 whilst working the calipers this has worked but I will strip them and do it properly thanks again

 

[curzons246]

Hve you got a washer betwixt brake and crown?

Yes just the one a star type washer - is that all there should be?