Stiff V-Brake arm

[ElyDave]

just replaced the V-Brakes on No1 daughter's MTB with some Tektro 430's, front went on with no issues, adjusted nicely.  Rear is a bit of an issue, the RHS arm (as you look from the rear) was harder to get off and very stiff to get the replacement onto the boss.  It's also not moving freely, so will pull in with the lever, but is not springing out again. 

My diagnosis is that the mounting boss is not straight and needs to be replaced?

[Paul H]

Have you swap tested front and rear?
It would be the first thing I'd do, establish if it's the brake or the boss.

[ElyDave]

I haven't, assuming new brakes are good.  Might be a false assumption of course.

[neilrj]

How was old brake arm? If it wasn't stiff it has to be a problem with new bit surely?

[ElyDave]

Old one was stiff to get off, previously I had to back off the rear to avoid rubbing, so historically not good either

[LittleWheelsandBig]

If the bolt has been overtightened, it flares the boss which then jams the V-brake.

https://yacf.co.uk/forum/index.php?topic=122407.0

[ElyDave]

So either way, looks like change the bosses on the back is a good idea, if sanding doesn't work

I used a torque wrench when I reassembled

[iandusud]

I've had to deal with flared bosses from over-tightening. Some careful work with file and some wet and dry will sort it out.

[Paul H]

I haven't, assuming new brakes are good.  Might be a false assumption of course.

Your assumption is almost certainly correct.  I'd still take the few minutes to swap them and remove the "almost".

[ElyDave]

It was a flared boss, 10 mins with a bit of wet and dry did the job. Thanks for the tip, must make sure to put that one in the memory bank.

Must have been a gorilla-fisted previous owner as I've not done anything with this brakewise since I've had it.