Hi,
I've just had my car looked at by a garage after failing it's mot for the second time.
First time one of the rear brakes was binding, it now has refurbed calipers with new discs and pads. It's now failed again on handbrake efficiency.
The garage have said I didn't pump the brakes back in properly before applying the handbrake, and that the calipers now need to be refurbed/replaced again as there's no way to readjust them. I wanted to check if this is correct before spending more money?
I found the old how to on handbrake adjustment but wasn't sure if it's applicable here. Also if I do try doing it myself again, what's a good way to test the handbrake before taking it back in for mot? It always held on a slope but obviously isn't enough for a pass.
Did you fit the refurbished calipers yourself and did you wind the piston all the way in and wind back ~90 degrees when it was fitted? If you did then adjusting the handbrake inside the car might help, if you didn't then suggest trying a rewind at the caliper end. 3 years running my '2 was failing on handbrake efficiency, I just adjusted the handbrake in the cabin and it passed, but did have to do it every year. I finally got some refurbished calipers and passed 2 years on the trot without issue.
There are several guides on here, mr2oc and imoc - I've been trying a few. Just had my handbrake cables replaced so this weekend's task is going to be to lube up slide bolts, clips etc. and try the other guides.
Some argument over it, but you're apparently meant to wind the piston all the way in, then rotate it out by 180 degrees, otherwise the auto adjuster does not engage.
Quote from: "onion86"Did you fit the refurbished calipers yourself and did you wind the piston all the way in and wind back ~90 degrees when it was fitted? If you did then adjusting the handbrake inside the car might help, if you didn't then suggest trying a rewind at the caliper end. 3 years running my '2 was failing on handbrake efficiency, I just adjusted the handbrake in the cabin and it passed, but did have to do it every year. I finally got some refurbished calipers and passed 2 years on the trot without issue.
The calipers came with instructions saying not to touch the piston and just fit them as they were already set for auto adjustment.
The mechanic has said they can't be reset now without being stripped down, which I thought seemed odd. Is there a reason winding the pistons back in wouldn't fix it?
They can be wound back in. Did you ensure the nipple on the back of the pad is located in the slot on the piston? The pad will be wonky and the auto-adjust won't work if they're not lined up. Also, did you check to see if the brake cable moves freely? When it's jacked up with the wheels on, see if you can rotate the wheel by hand. If it's working you won't be able to.
The cables seemed ok when I put the calipers on. The handbrake does work just not well enough to pass MOT, I wouldn't have thought I could apply enough force by hand to test them properly?
So the best course of action is to wind the pistons all the way back in then back out a bit, make sure it's lined up with the pads then pump the brake pedal a lot?
Do I need to disconnect the cables while I do this or just release the lever?
You've got the idea. Just let the handbrake off. Ten hard pedal pumps. Hand spin (with the leverage the tyre gives) is a good indication. Did you run the pads in? I say this because I helped another member who had rear brake issues (he'd bought new calipers and cables ready to install), could find nothing wrong with the existing system, it turned out to be ineffective pads. You might also need to adjust the handbrake lever a bit.
Thanks, I'll give that a go.
Make sure that the pin on the rear of the inner brake pad actually fits into the caliper piston slot. Quite often the replacement calipers are for an earlier MR2 model which has a smaller slot... I've suffered this problem twice!
As said, the calipers certainly can be reset. Wind the piston in all the way, then wind out around 180 degs until the piston slot is correctly aligned. Personally I always unbolt the cable bracket from the calipers when doing this, and only reconnect after pumping the foot brake hard a dozen times.
Quote from: "Jon_G"Make sure that the pin on the rear of the inner brake pad actually fits into the caliper piston slot. Quite often the replacement calipers are for an earlier MR2 model which has a smaller slot... I've suffered this problem twice!
As said, the calipers certainly can be reset. Wind the piston in all the way, then wind out around 180 degs until the piston slot is correctly aligned. Personally I always unbolt the cable bracket from the calipers when doing this, and only reconnect after pumping the foot brake hard a dozen times.
I've had that problem too. Overcame it by filing the nipple a little to make it fit.
Quote from: "Carolyn"Quote from: "Jon_G"Make sure that the pin on the rear of the inner brake pad actually fits into the caliper piston slot. Quite often the replacement calipers are for an earlier MR2 model which has a smaller slot... I've suffered this problem twice!
As said, the calipers certainly can be reset. Wind the piston in all the way, then wind out around 180 degs until the piston slot is correctly aligned. Personally I always unbolt the cable bracket from the calipers when doing this, and only reconnect after pumping the foot brake hard a dozen times.
I've had that problem too. Overcame it by filing the nipple a little to make it fit.
Annoying that it happens though! I bought Mk2 pads...
I finally got around to trying this but I'm having a nightmare trying to wind the piston back in. It moved easily for a short distance either direction and now it won't budge, what am i doing wrong?
Is it all the way in? Might be jammed at the bottom of the thread. A small push on the pedal will (hopefully) push the piston out a little and then it should turn...
Gently does it.
If you're tool is the wrong hand thread, it'll jam as you try to wind it
Quote from: "jonbill"If you're tool is the wrong hand thread, it'll jam as you try to wind it
GOOD POINT.
Which rewind tool are you using?
This one?:-
Look at this on eBay m http://www.ebay.co.uk/itm/262819831299 (http://www.ebay.co.uk/itm/262819831299) m
It's tricky to correctly set it. The shaft on the tool doesn't quite advance at the same rate that the caliper piston retracts. This mean the the setting plate needs to be reset every turn or so. Once you get your head round that you'll be fine.
For what it's worth as my pads are worn I was able to use the tool in the link above to take mine out approx 360 degrees. As above, the plate means you have to do some jiggery pokery, and if your pads are new, you may have to do the last bit without the plate.
The piston will continue to rotate when fully wound in, albeit it won't wind in any further, so you'll have to do that part without the plate. You may need to rotate it at this point to be able to achieve a full 180 out, for the notch on the back of the pad to fit.
Hope that makes sense. It's fixed my nearside, albeit not the offside but I think the arm on the calipers is stiff on that side.
Quote from: "gazza1286"Which rewind tool are you using?
This one?:-
Look at this on eBay m http://www.ebay.co.uk/itm/262819831299 (http://www.ebay.co.uk/itm/262819831299) m
It's tricky to correctly set it. The shaft on the tool doesn't quite advance at the same rate that the caliper piston retracts. This mean the the setting plate needs to be reset every turn or so. Once you get your head round that you'll be fine.
It is this one. I got the right hand thread one, I used it to do the pads before so it should be correct? Was hard work then but that was with old dirty pistons, it seems even harder now.
The tool is currently jammed into the caliper anyway and will have to stay there until next weekend.