replaced rear pads- but handbrake now rubbish!

[Ian Geary]

As per title really. Handbrake is now really hard to pull up, and does nothing when you do. Footbrake works great though.

I didn't follow Paul Wood's advice from this topic http://www.imoc.co.uk/forums/viewtopic. ... ht=caliper

I just wound in the caliper piston enough to clear the new pads, and I didn't disconnect the handbrake cable either.

So what do I need to do to sort my handbrake?

- disconnect handbrake cable from caliper first? or can I leave it connected?
- wind in piston a further 180 degrees, then wind it out again to reset handbrake?

This will teach me not to try and cut corners!

Ian

[lower]

this is the link to the BGB article on how to change the rear brake pads

http://www.mr2-tech.com/bgb/mechanical/ ... system.htm

i've not heard about the 180 degree exact turn thing that paul mentions. whilst i do not want to disagree with him, all you should need to do is wind the piston back far enough so that the pad does not touch the disc. when you reassemble the brakes and apply pressure to the brake pedal the piston will move out in the normal way as per when the pad wears and the handbrake should adjust properly.

all the bgb mentions is lining up the cut outs with the lug on the back of the pad. when i did my brakes, i followed the bgb, had no problems and did not have to remove the handbrake cable.

i would suggest stripping them down again and making sure that the handbrake cables are not caught or twisted on anything, moves freely and that the lugs line up.

i have had problems on other cars with hydraulic rear brakes with the handbrake mechanism not reseting properly and it needing a few really hard yanks and pushes on the brake pedal to get it to reset. my mechanic father in law who was helping me with the brakes said that that was often the case. but the handbrake was not stiff, which is why i ask if something is caught or twisted.

[PW@Woodsport]

ian the reason your h/brake is a pile of poo is cos you need to wind the pistons back out at least 180degs.....all you need to do is follow that link you have and it will 100% work....its amazing how many people just wind the pistons back without slackening off the cable first,and winding them back out 180 degs is ESSENTIAL for the h/brake to work again,but i did warn about this some weeks ago.....if you need a walkthrough on the proceedure email me and i will help you out.

For anyone else reading,if you just wind the pistons right back and then fit the new pads you wont have a h/brake at all,follow the advice chaps,i know what im talking about believe it or not

[Ian Geary]

cheers lower,

it could well be twisted - pulling the handbrake lever up and down wasn't moving anything on the caliper when we had another look - surely it should pull the crank in, which then pushes the piston out onto the pads.

Oh well, it will have to wait until tomorrow now.

Ian

[lower]

paul,

i'm sure you do know what you're talking about as i'm sure you have changed far more brake pads than me, but why do you need to wind the piston back out 180 degrees? obviously you have a technique that you've discovered through experience but i'm intrigued to know exactly what is occuring mechnically when you wind the piston back out.

ian the reason your h/brake is a pile of poo is cos you need to wind the pistons back out at least 180degs.....all you need to do is follow that link you have and it will 100% work....its amazing how many people just wind the pistons back without slackening off the cable first,and winding them back out 180 degs is ESSENTIAL for the h/brake to work again,but i did warn about this some weeks ago.....if you need a walkthrough on the proceedure email me and i will help you out.

For anyone else reading,if you just wind the pistons right back and then fit the new pads you wont have a h/brake at all,follow the advice chaps,i know what im talking about believe it or not

[PW@Woodsport]

ok lower....internally on all mr2 rear calipers there is a small mechanism that doesnt come into contact with the piston lever until you wind back out by 180 degs,if you just wind the piston all the way in, this mechanism is not engaged and the h/brake lever isnt acting upon anything and as ian has found out,you get no h/brake whatsoever....this isnt a new discovery,ive known about it for a long time but cant be ar$ed to keep typing the same advice about rear calipers over and over,especially when there are so many "experts" out there who know better.

Bottom line is if you take the general advice given on forums on fitting rear mr2 pads 9/10 you will have no h/brake or a very poor one as not many people know about the reset method,but this can only be done with the cables slackened off as you would do on any other make of car.

Why is this so important? because it affects the adjustment of the piston...and rear brakes are ultra important,if you have a poorly adjusted rear it affects the fronts,set up the rears properly as per my advice and the fronts will improve dramatically.This is done by winding the piston in to a point where when it comes back out 180 it will be a perfect interference fit with the pads ie slightly rubbing when you turn the disc,not binding i hasten to add....it takes time and experimenting to get them right,but the golden rule is each time they are wound right in they must be wound out 180 so the trick is to wind in all the way until it goes in no further,position (A)align the piston holes at 90 degs to the caliper and then wind in say 190-200 degs(B),when its wound out 180(C) it should be very close to a perfect fit,if its not then wind back in to position A and make position B 210 degrees for example until the caliper to pad fit is perfect.

OR! totally ignore the above as most do and continue to fit rear pads as everyone seems to advise and end up with shat brakes... sorry if im ratty but misinforming keyboard mechanics should stop posting if they dont actually know what they are talking about or simply regurgitating something they read on another misinformed post.....im off for a lie down.

[stevecordiner]

I didn't follow Paul Wood's advice from this topic http://www.imoc.co.uk/forums/viewtopic. ... ht=caliper

Sorry ... that was the first mistake Mr Woods has done more crazy stuff with mr2's than anyone else in Europe and is right up there with quite a few of the crazy guys in the US. Follow his advice chaps

[Frustrated Pilot]

good show woods!!!!!

i even told my mechanics to wind it 180... but they failed to act on this as 'i'm only a suit'

therefore no rear breaks or calipers... i gotta put my feet out the door or hang on to a tree to stop...

[lower]

this is the bit i don't get. the piston is hydraulicly actuated so how does winding it back out 180 degrees affect the effectiveness of the rear brakes? if you wind it all the way back in and fit the pads, as soon as you apply pressure to the brake pedal then the piston will move out and push the pads into the correct position against the disc.

agreed, it is sometimes a pain to get the handbrake mechanism to engage properly, but a few hard applications of the handbrake lever and pumps of the brake pedal gets it to engage and then the handbrake works perfectly well. if your method of winding the piston back out 180 degrees guarentees that the handbrake mechanism works every time then it is undoubtably a good technique, but to say you will not have a handbrake unless you do this is plain wrong.

ok lower....internally on all mr2 rear calipers there is a small mechanism that doesnt come into contact with the piston lever until you wind back out by 180 degs,if you just wind the piston all the way in, this mechanism is not engaged and the h/brake lever isnt acting upon anything and as ian has found out,you get no h/brake whatsoever....this isnt a new discovery,ive known about it for a long time but cant be bummed to keep typing the same advice about rear calipers over and over,especially when there are so many "experts" out there who know better.

Bottom line is if you take the general advice given on forums on fitting rear mr2 pads 9/10 you will have no h/brake or a very poor one as not many people know about the reset method,but this can only be done with the cables slackened off as you would do on any other make of car.

Why is this so important? because it affects the adjustment of the piston...and rear brakes are ultra important,if you have a poorly adjusted rear it affects the fronts,set up the rears properly as per my advice and the fronts will improve dramatically.This is done by winding the piston in to a point where when it comes back out 180 it will be a perfect interference fit with the pads ie slightly rubbing when you turn the disc,not binding i hasten to add....it takes time and experimenting to get them right,but the golden rule is each time they are wound right in they must be wound out 180 so the trick is to wind in all the way until it goes in no further,position (A)align the piston holes at 90 degs to the caliper and then wind in say 190-200 degs(B),when its wound out 180(C) it should be very close to a perfect fit,if its not then wind back in to position A and make position B 210 degrees for example until the caliper to pad fit is perfect.

OR! totally ignore the above as most do and continue to fit rear pads as everyone seems to advise and end up with shat brakes... sorry if im ratty but misinforming keyboard mechanics should stop posting if they dont actually know what they are talking about or simply regurgitating something they read on another misinformed post.....im off for a lie down.

[Speedy]

Does this 180 thing apply to mk1s as well, or just mk2?

[PW@Woodsport]

if you wind it all the way back in and fit the pads, as soon as you apply pressure to the brake pedal then the piston will move out and push the pads into the correct position against the disc.

yes but its the AMOUNT the piston has to travel when pressing the footbrake that determines how good the pedal is....on an mr2 the footbrake is on a completely separate system to the h/brake as per MOT law....the footbrake is hydraulic only,the h/brake is mechanical,they only share the same piston ,there the similarity ends.

Bottom line is if you wind the piston all the way back and fit new pads you will have a crap or v poor h/brake,it MUST be wound back out 180 degs to reset the calipers internal h/brake mechanism.

I dont see why im having to justify why this is how it should be done when everyone else usually incorrectly advises just wind the pistons back and fit the pads without having to explain the whys???? take it from me bud,this is the correct and ONLY way to do it,for years ive watched them being fitted wrongly.....and yes speedy this applies to mk2's as well mate.

[PW@Woodsport]

sorry speedy i mean mk1's as well....

[Speedy]

Thanks for that - somebody *cough* should put this useful tip into somesort of Knowledge Base *cough* *cough*

[lower]

totally agree. it is the amount the piston has to travel that determines how good the pedal is. but as soon as you have applied the foot brake once, the piston and pads move into the correct position. the piston then stays out and does not retract back to its initial position unless you have major run out on your discs.

Paul, don't me wrong, i am not arguing with you for the sake of it or disputing your undoubted knowledge and experience of mr2's, but your statement that you will not get a decent rear hand brake unless you rotate out the piston 180 degrees is not correct. if your method guarentees it first time every time then that is a valuable piece of info from which all can benefit. however, the basic method as shown in the bgb does work and gives a correctly working handbrake if followed. there will however be some occasions where the handbrake does not work correctly for a good few applications because the handbrake mechanism has not engaged. but a few good hard appliactions of the footbrake and hard pulls on the handbrake reengages it and it will then work correctly.

you've accused me of being a keyboard mechanic because i've disagreed with you and i totally agree that keyboard mechanics that give bad advice are dangerous. but people listen to you because they know of the depth of your experience and you telling people that if they haven't done it your way they won't have a correctly working foot or handbrake is scaremongering and could lead to people stripping down and resetting rear brakes that were already working perfectly.

if you wind it all the way back in and fit the pads, as soon as you apply pressure to the brake pedal then the piston will move out and push the pads into the correct position against the disc.

yes but its the AMOUNT the piston has to travel when pressing the footbrake that determines how good the pedal is....on an mr2 the footbrake is on a completely separate system to the h/brake as per MOT law....the footbrake is hydraulic only,the h/brake is mechanical,they only share the same piston ,there the similarity ends.

Bottom line is if you wind the piston all the way back and fit new pads you will have a crap or v poor h/brake,it MUST be wound back out 180 degs to reset the calipers internal h/brake mechanism.

I dont see why im having to justify why this is how it should be done when everyone else usually incorrectly advises just wind the pistons back and fit the pads without having to explain the whys???? take it from me bud,this is the correct and ONLY way to do it,for years ive watched them being fitted wrongly.....and yes speedy this applies to mk2's as well mate.

[PW@Woodsport]

ok forget everything i said,just wind the pistons back like ian did and enjoy your car,im clearly talking rubbish,good luck.

[lower]

i did, and they were fine. every time.

[PW@Woodsport]

you need to go do some research bud....ive been working on these calipers for years,its not a hobby,its my profession...i can 100% guarantee if you wind an mr2 (mk1 or mk2) rear piston all the way back and fit new pads without turning back out 180 the handbrake wont work properly....its not scaremongery as you suggest,its fact.

Why would i make something like that up???

I cant be bothered to argue about it,but you ARE wrong my friend,why do you think ian initially posted? ive seen this for years....hell in the early days some 8 years ago i used to just wind them back myself,stand back scratching my head why the h/brake was poor.

If you think my advice is wrong then ignore it,as i said enjoy your car....but dont ever accuse me of scaremongery when im giving advice i know is 100% accurate,i wouldnt dream of telling you how to do your job.

Maybe i shouldnt have bothered!!!!

[robw]

what s the point in all this, If someone who runs a mr2 specialist garage offers advice for free I think i would follow it, just look how many posts paul woods answers and problems he helps with!

[robw]

i m just sorting out my rear brakes this week so thanks for the advice paul!

[PW@Woodsport]

you're welcome rob