Handbrake Confusion - Lever on Calipers
Discussion
Evening all,
I'm posting this as I can't work out what is going on.
Today I changed both rear wheel bearings on my car (Mk6 Fiesta ST150) but I'm not having trouble getting the handbrake to apply equally on both sides (note I don't know if it was equal before today). My confusion is that the lever on the back of the calipers move by different amounts when the handbrake is applied. The side with the greater movement is also the side which is less effective, which I feel is counter intuitive. The same side also has slightly less brake force when using the brake pedal.
I've bled both sides - no issues.
I've taken up some of the slack using the nut on he handbrake lever, and will probably take out some more as the handbrake still isn't great.
Is there anything I might have missed/misunderstood? Why would the caliper levers move by different amounts?
Cheers
I'm posting this as I can't work out what is going on.
Today I changed both rear wheel bearings on my car (Mk6 Fiesta ST150) but I'm not having trouble getting the handbrake to apply equally on both sides (note I don't know if it was equal before today). My confusion is that the lever on the back of the calipers move by different amounts when the handbrake is applied. The side with the greater movement is also the side which is less effective, which I feel is counter intuitive. The same side also has slightly less brake force when using the brake pedal.
I've bled both sides - no issues.
I've taken up some of the slack using the nut on he handbrake lever, and will probably take out some more as the handbrake still isn't great.
Is there anything I might have missed/misunderstood? Why would the caliper levers move by different amounts?
Cheers
The handbrake cable will typically be connected to both calipers and the lever will pull in the middle. Whichever caliper has least resistance will get the most travel.
Most handbrake mechanisms have a self-adjuster built in. If it's stuck / broken on one side that side will never adjust to take up the slack on the caliper.
Did you dismantle the caliper or push back the piston while you were taking things apart?
Most handbrake mechanisms have a self-adjuster built in. If it's stuck / broken on one side that side will never adjust to take up the slack on the caliper.
Did you dismantle the caliper or push back the piston while you were taking things apart?
GreenV8S said:
The handbrake cable will typically be connected to both calipers and the lever will pull in the middle. Whichever caliper has least resistance will get the most travel.
Most handbrake mechanisms have a self-adjuster built in. If it's stuck / broken on one side that side will never adjust to take up the slack on the caliper.
Did you dismantle the caliper or push back the piston while you were taking things apart?
Thanks for your reply.Most handbrake mechanisms have a self-adjuster built in. If it's stuck / broken on one side that side will never adjust to take up the slack on the caliper.
Did you dismantle the caliper or push back the piston while you were taking things apart?
You are correct, the handbrake lever pulls on a bar underneath the car, which splits off to both calipers.
I think the caliper which moves more had a bigger gap between the pads and disc, but I've since taken most of that up by pressing the brake pedal 15 or so times. I've also readjusted the handbrake from inside the car which has improved its feel/brake force but the caliper levers still move different amounts.
I did wind the piston in by 1/4 turn on the side which moves more, but I put it back 1/4 turn as I thought that was the issue.
Part of me wonders whether I am over analysing it. I'm also tempted to let the brakes settle and see what happens.
I've not worked on one of those specifically, but on a lot of designs, if you pull the handbrake lever first when the brakes are freshly fitted and "slack", it can mess up how they take up the free movement. Are you sure you didn't absent minded pull the lever before having pressed the pedal?
First thing I'd try is winding both the calipers in a little, making sure the handbrake actuator on the calipers is fully "out", then putting it all back together an pressing the brake pedal a few times to bring the piston out. Give it a drive up and down the road and check the footbrake all feels OK, and only then mess with the handbrake.
Obviously, if the workshop manual says do it otherwise, try that way.
This is assuming that the mechanism on the caliper isn't partially seized, they can be bloody awful on some cars.
First thing I'd try is winding both the calipers in a little, making sure the handbrake actuator on the calipers is fully "out", then putting it all back together an pressing the brake pedal a few times to bring the piston out. Give it a drive up and down the road and check the footbrake all feels OK, and only then mess with the handbrake.
Obviously, if the workshop manual says do it otherwise, try that way.
This is assuming that the mechanism on the caliper isn't partially seized, they can be bloody awful on some cars.
InitialDave said:
I've not worked on one of those specifically, but on a lot of designs, if you pull the handbrake lever first when the brakes are freshly fitted and "slack", it can mess up how they take up the free movement. Are you sure you didn't absent minded pull the lever before having pressed the pedal?
First thing I'd try is winding both the calipers in a little, making sure the handbrake actuator on the calipers is fully "out", then putting it all back together an pressing the brake pedal a few times to bring the piston out. Give it a drive up and down the road and check the footbrake all feels OK, and only then mess with the handbrake.
Obviously, if the workshop manual says do it otherwise, try that way.
This is assuming that the mechanism on the caliper isn't partially seized, they can be bloody awful on some cars.
Cheers for your thoughts.First thing I'd try is winding both the calipers in a little, making sure the handbrake actuator on the calipers is fully "out", then putting it all back together an pressing the brake pedal a few times to bring the piston out. Give it a drive up and down the road and check the footbrake all feels OK, and only then mess with the handbrake.
Obviously, if the workshop manual says do it otherwise, try that way.
This is assuming that the mechanism on the caliper isn't partially seized, they can be bloody awful on some cars.
I can't honestly say I didn't pull the handbrake lever first. I like your idea of winding both the calipers in, in that it would reset them a bit like installing new calipers. Then doing it properly!
I remain hopeful that they aren't partially seized as they were rebuilt a couple of years ago.
Make sure you haven't taken up slack at the handle end. On all the cars I've seen, that slack is essential for the self-adjuster in the caliper to get enough travel. The procedure is typically to press and hold the brakes and then repeatedly apply and release the handbrake. This operates the ratchet in the caliper which gradually winds the adjuster out.
If you're dismantled the handbrake mechanism it's possible that the adjuster hasn't been set properly and is now effectively stuck.
If you're dismantled the handbrake mechanism it's possible that the adjuster hasn't been set properly and is now effectively stuck.
I've not had chance to take it apart again, thanks to work, but my intention is to do just as you say - wind the pistons in on both sides, press the brakes lots to reset the calipers. I need to do something as I'm not sure the pads are sweeping the whole of the disc.
Hopefully I'll get a chance on Sunday/Monday. I'll update the thread once I have though
Hopefully I'll get a chance on Sunday/Monday. I'll update the thread once I have though
Follow the procedure in this link which covers it. https://pmmonline.co.uk/technical/hand-brake-adjus...
Finally had a chance to have a look at this today.
Long story short, I think I've got a seized caliper, possibly two.
I wound both pistons in nearly all the way, but made sure they were the same both sides. Then when I pressed the brake pedal, only one caliper took up the space between the piston and pads. The other side piston would move slightly with a press of the brake pedal, but would move back to the same place when the pedal was released. No amount of pedal presses or bleeding sorted this, so eventually in order to get a reasonable pedal and the brakes work, I wound the piston out by hand so the free play was roughly 1mm. Both pistons were very difficult to wind in or out even with the bleed nipple loose so I think the pistons and or ratchet mechanisms are seized.
Long story short, I think I've got a seized caliper, possibly two.
I wound both pistons in nearly all the way, but made sure they were the same both sides. Then when I pressed the brake pedal, only one caliper took up the space between the piston and pads. The other side piston would move slightly with a press of the brake pedal, but would move back to the same place when the pedal was released. No amount of pedal presses or bleeding sorted this, so eventually in order to get a reasonable pedal and the brakes work, I wound the piston out by hand so the free play was roughly 1mm. Both pistons were very difficult to wind in or out even with the bleed nipple loose so I think the pistons and or ratchet mechanisms are seized.
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