Friday, 30 November 2012

The smell of burning!


Over heated rear brake disc.
I was in a hurry the other day to get the dog to the vet. It was not until I was part way up the bypass that I realised that the handbrake had stuck on. Even though the hand brake leaver in the cab was completely off, the smell of brake linings was over powering. It's just as well the vets was not to far, even so the back wheels were so hot you could not touch them. Just before we made the return journey I slipped under the van and pulled back the little arms that operate the handbrake on the back of the calipers. Man they we tight! This does not bode well for those new wheel bearings that were fitted earlier in the year. A sticking hand brake is one of the reasons why the bearing failed in the first place!
 

Showing handbrake arm on Caliper
With the back of the van up in the air and both the wheels off, it is time to get to grips with sorting this problem out. On further investigation it turns out that the shaft that sticks out of the back of the calliper with the handbrake actuation arm on, has rusted tight. Even though there is a little rubber cup that sits between the calliper and the arm to protect the shaft from the weather. I believe this is its down fall because once the water gets behind the seal it remains there helping the rust to build up causing it to seize. 

 
Once the handbrake cable has been loosened you can remove the end of the cable from the arm more easily, with a bit of fiddling. To free the arm off you will need  to tap it backwards and forwards with a medium weight hammer. Do not over do the amount of force you use when hitting the arm with the hammer. The idea is not to do it in one hit but to keep moving it up and down until the sprung loaded arm moves  back to the off position on it's own. When it feels like it has freed off enough to move it easily by hand, you need to check it's at the off position. If not it is time to take a closer look at the spring. If the metal of the spring is pitted and heavily rusted it is possible that it has lost some of its tension. For the three or so pounds each it costs to replace these springs it is not worth messing about. Removing the spring from the arm is a bit annoying but straight forward with a pair of pliers.
Handbrake arm spring old and new

 
There is one last thing to do as a suggestion before you box it up and that is to get some white grease and push it in behind the little rubber seal that protects the the handbrake arm shaft this will help to keep things moving and the weather out.

 
I have used this method on my van and so far the hand brake has not stuck on again.

 
Related post rear wheel bearing replacement.