MOT fail, Rear Brake Imbalance and Hand Brake
Discussion
Hey guys,
Having a bit of a problem with my MG ZS, recently one of the rear calipers seized on so I had to replace it.
This calipers has now failed the MOT due to the handbrake not fully operating and also the foot brake operation being lower than the other side.
I've checked the following:
Calipers piston aligned with pad
Handbrake mecanisum not sticking
Handbrake mechanism rests on the stops when disengaged
Handbrake cables move freely and equal
Handbrake tension
The handbrake mechanism on the calipers are moving the same amount so sound be providing the same force. The only thing I can think of is the rear pads are goosed where it was driven with the calipers locked.
Any thoughts?
Having a bit of a problem with my MG ZS, recently one of the rear calipers seized on so I had to replace it.
This calipers has now failed the MOT due to the handbrake not fully operating and also the foot brake operation being lower than the other side.
I've checked the following:
Calipers piston aligned with pad
Handbrake mecanisum not sticking
Handbrake mechanism rests on the stops when disengaged
Handbrake cables move freely and equal
Handbrake tension
The handbrake mechanism on the calipers are moving the same amount so sound be providing the same force. The only thing I can think of is the rear pads are goosed where it was driven with the calipers locked.
Any thoughts?
The fact the brakes on one side aren't working correctly suggests that either the two sides aren't producing the same clamping force, of the friction characteristics are different from side to side.
Are you saying you refitted the pads from the knackered caliper that may have been overheating? That wasn't a good idea and could well be causing the problem. In that case it would be a good idea to replace the pads on both sides, flush and bleed the brakes.
If the handbrake isn't working correctly, find out how the adjustment mechanism works and whether it is adjusted correctly. Some systems have an internal ratchet system in the caliper to take up pad wear, and a separate adjuster on the cable to take up cable stretch. They both need to be adjusted correctly. If you try to take up pad wear on the cable adjuster, you will eventually run out of travel in the handbrake mechanism in the caliper.
Are you saying you refitted the pads from the knackered caliper that may have been overheating? That wasn't a good idea and could well be causing the problem. In that case it would be a good idea to replace the pads on both sides, flush and bleed the brakes.
If the handbrake isn't working correctly, find out how the adjustment mechanism works and whether it is adjusted correctly. Some systems have an internal ratchet system in the caliper to take up pad wear, and a separate adjuster on the cable to take up cable stretch. They both need to be adjusted correctly. If you try to take up pad wear on the cable adjuster, you will eventually run out of travel in the handbrake mechanism in the caliper.
Yeah I put the old pads back in (live and learn) the calipers are auto adjusting with ratchets inside the caliper which uses the foot brake to adjust. The cable slack is taken up buy an equalizing bar on the back of the hand brake cable. This is also set up correctly. Fluid was changed when I did the caliper, worth changing the disc's too? It doesn't look warped but they are not expensive.
Change the pads both sides and if the disc is a bluish colour on the caliper that was seized its likely that has been cooked up and nicely glazed over so that will need changing too - Make sure there is no grease on any of the friction surfaces - general rule with pads and discs is change in pairs otherwise you end up with imbalance
It seems that you are focusing on the caliper when you don't actually know that is the issue.
The pads & disc/hat & shoes are potentially just as likely to be the issue.
Check over the caliper, make sure everything is working well & releasing as it should, change the pads, change the discs.
Slacken off the handbrake cable at the lever, change the shoes, check everything is as it should be (one side at a time starting with the bad side so you have a good reference) then adjust the shoes up correctly and re-tighten the handbrake cable correctly.
If all the above happens as it should you should be good to go.
The pads & disc/hat & shoes are potentially just as likely to be the issue.
Check over the caliper, make sure everything is working well & releasing as it should, change the pads, change the discs.
Slacken off the handbrake cable at the lever, change the shoes, check everything is as it should be (one side at a time starting with the bad side so you have a good reference) then adjust the shoes up correctly and re-tighten the handbrake cable correctly.
If all the above happens as it should you should be good to go.
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