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Rear Brake Sticking
+4
Nick
Rich
uk kiwis
StevePem
8 posters
Page 1 of 2 • 1, 2
Rear Brake Sticking
My offside rear brake is sticking on the ZS. It is intermitent so hoping it may be possible to free it up rather than replace the caliper. Is it likely to be just the pistons themselves or the guides sticking? What do I need to clean and what do I need to squirt with plus gas?
Don't really want to trek up to Corby just to get the one brake done, is there anywhere local to MK or Olney recomended if I can't sort it?
Can I trust the local Kwik Fit types to do it as I need the aircon pumping up anyway
Cheers
Steve
Don't really want to trek up to Corby just to get the one brake done, is there anywhere local to MK or Olney recomended if I can't sort it?
Can I trust the local Kwik Fit types to do it as I need the aircon pumping up anyway
Cheers
Steve
StevePem- Registered user
Re: Rear Brake Sticking
From my experience once this happens it usually confirms a brake cylinder is on the way out. It will not get better on its own sadly as oil gets into the rubber seals and they deteriate eventually. Not an uncommon problem as you will be aware no doubt............
uk kiwis- Registered user
Re: Rear Brake Sticking
It's a common problem on ZSs and 45s. Mine started binding a little and got worse from there until it completely seized. The caliper piston screws in and out rather than sliding straight and the thread corrodes until it just wont move. If you've caught it early enough, you may be able to free it up with a bit of WD40 and mole grips, obviously after removing it from the car. Hopefully Matt can give you a more in depth 'how to'. Worth trying yourself first rather than paying a garage miles away.
Rich
Rich
Re: Rear Brake Sticking
Thanks guys. Will get the wheel off and have a look at the weekend.
So if I wind the piston in and out and spray a bit of plusgas in at the same time it could free it up?
So if I wind the piston in and out and spray a bit of plusgas in at the same time it could free it up?
StevePem- Registered user
Re: Rear Brake Sticking
Steve, I have a brake wind back tool that you're welcome to borrow if you need to borrow it...
Nick- Admin/Moderator
Re: Rear Brake Sticking
As Rich said, but just need to correct him slightly
Rear caliper sticking/seizing is a very common fault on the 400/45/ZS mainly the nearside due to being in the gutter all the time.
The caliper pistons seize in the caliper from all the water getting in around the seals and corroding the piston making it thicker and because of this corrosion the piston can no longer move freely. The piston works in the standard way of sliding out when under pressure and back in once released but unlike front brake calipers when you can push back the piston into the caliper when fitting new pads etc the rear caliper pistons have to be wound in as when the pads wear down the pistons wind out slightly due to being located on a thread.
To wind the pistons back in you ideally need a caliper wind back tool with the correct size platform head(disc that has locator pegs on it) but you can use a prybar or long nose pliers and what you need to do is apply pressure as pushing the piston in but at the same time as screwing it in.
If the piston wont move back in your more than likely find the corrosion on the piston it quite bad(as was my ZS caliper) and you will have to unscrew the piston out of the caliper and clean the piston up removing all of the corrosion, then you will have the fun task of trying to screw the piston back in whilst hooking over the dust seal, very fiddly
If you want to see a pic of how bad my caliper piston was let me know and I'll show you lol
Speaking of brakes, I have some new ones for the front to go on the ZS
Rear caliper sticking/seizing is a very common fault on the 400/45/ZS mainly the nearside due to being in the gutter all the time.
The caliper pistons seize in the caliper from all the water getting in around the seals and corroding the piston making it thicker and because of this corrosion the piston can no longer move freely. The piston works in the standard way of sliding out when under pressure and back in once released but unlike front brake calipers when you can push back the piston into the caliper when fitting new pads etc the rear caliper pistons have to be wound in as when the pads wear down the pistons wind out slightly due to being located on a thread.
To wind the pistons back in you ideally need a caliper wind back tool with the correct size platform head(disc that has locator pegs on it) but you can use a prybar or long nose pliers and what you need to do is apply pressure as pushing the piston in but at the same time as screwing it in.
If the piston wont move back in your more than likely find the corrosion on the piston it quite bad(as was my ZS caliper) and you will have to unscrew the piston out of the caliper and clean the piston up removing all of the corrosion, then you will have the fun task of trying to screw the piston back in whilst hooking over the dust seal, very fiddly
If you want to see a pic of how bad my caliper piston was let me know and I'll show you lol
Speaking of brakes, I have some new ones for the front to go on the ZS
Matt Parker- Registered user
Re: Rear Brake Sticking
There you go then... Who needs mole grips when you can have the proper kit!Nick wrote:Steve, I have a brake wind back tool that you're welcome to borrow if you need to borrow it...
Rich
Re: Rear Brake Sticking
Thanks again all,
Nick, I will try to have ago this weekend but could you bring the windback tool on Thursday just in case?
Thanks for the detailed description Matt.
If the piston is not seized completely, should I just spray a bit of plusgas into the tread and work it in and out? Should it be lubricated with anything? When I put it back together should should I wind the piston all the way back into the caliper?
It is the off side one that is sticking. When I had the car serviced & MoTd in April it seems both the nearside front and rear had been sticking and were freed up.
I first noticed this one sticking after I had not used the car for a few days. It was sticking in the morning when I used it but then lunch time and evening it was fine. It did the same thing again this week when I used the car so I thought maybe it was the handbrake that had been sticking. I parked without the handbrake that night but next day it was sticking morning, lunchtime and going home at night.
Nick, I will try to have ago this weekend but could you bring the windback tool on Thursday just in case?
Thanks for the detailed description Matt.
If the piston is not seized completely, should I just spray a bit of plusgas into the tread and work it in and out? Should it be lubricated with anything? When I put it back together should should I wind the piston all the way back into the caliper?
It is the off side one that is sticking. When I had the car serviced & MoTd in April it seems both the nearside front and rear had been sticking and were freed up.
I first noticed this one sticking after I had not used the car for a few days. It was sticking in the morning when I used it but then lunch time and evening it was fine. It did the same thing again this week when I used the car so I thought maybe it was the handbrake that had been sticking. I parked without the handbrake that night but next day it was sticking morning, lunchtime and going home at night.
StevePem- Registered user
Re: Rear Brake Sticking
I have a spare pair of rear brake callipers, if you need a replacement.
adrianvvc- Registered user
Re: Rear Brake Sticking
Thanks Adrian, I will see if I can free it up at the weekend but may well take you up on the offer.
Cheers
Steve
Cheers
Steve
StevePem- Registered user
Re: Rear Brake Sticking
Are the MGF and ZS ones the same, or have you actually got some ZS callipers?adrianvvc wrote:I have a spare pair of rear brake callipers, if you need a replacement.
Rich
Re: Rear Brake Sticking
StevePem wrote:Thanks again all,
Nick, I will try to have ago this weekend but could you bring the windback tool on Thursday just in case?
Sorry Steve, but I wont be abel to make Thursdays meet as I'm at the British Grand Prix from Thursday to Sunday...I'm proper excited
I've got the following monday off so could drop you the windback tool then if that helps?
Nick- Admin/Moderator
Re: Rear Brake Sticking
Calipers are different Rich.
The piston's will benefit from some lubrication like anti seize copper grease.
Screw the piston all the way into the caliper and place the caliper over the pads back onto the carrier, see how much distance there is between the piston of the inner brake pad with the outer brake pad flush against the outside of the brake caliper arms. What you want is to have about 1-3mm of clearance between the caliper and brake pads so scrw out the piston but making sure that you have the + cut out of the piston vertical to the caliper so the lug of the inner brake pad can locate. Once you have the right amount of clearance(can wriggle the caliper abit and the disc turns freely) with the caliper fully bolted back on, pump the brake pedal to take the final bit of slack out of the pads and then check the operation of the hand brake.
Do NOT operate the hand brake until the foot brake has been pumped otherwise you will wind the piston out and it will leave the park brake lever of the caliper in the on possition but with the brakes off giving you NO hand brake.
I could describe this better but Im tired
The piston's will benefit from some lubrication like anti seize copper grease.
Screw the piston all the way into the caliper and place the caliper over the pads back onto the carrier, see how much distance there is between the piston of the inner brake pad with the outer brake pad flush against the outside of the brake caliper arms. What you want is to have about 1-3mm of clearance between the caliper and brake pads so scrw out the piston but making sure that you have the + cut out of the piston vertical to the caliper so the lug of the inner brake pad can locate. Once you have the right amount of clearance(can wriggle the caliper abit and the disc turns freely) with the caliper fully bolted back on, pump the brake pedal to take the final bit of slack out of the pads and then check the operation of the hand brake.
Do NOT operate the hand brake until the foot brake has been pumped otherwise you will wind the piston out and it will leave the park brake lever of the caliper in the on possition but with the brakes off giving you NO hand brake.
I could describe this better but Im tired
Matt Parker- Registered user
Re: Rear Brake Sticking
That's what I thought. I think Adrian might have thought we were talking about Steve's TF. I did ask if his were ZS ones but he hasn't replied...Matt Parker wrote:Calipers are different Rich.
A pretty good, detailed 'How To' there anyway Matt. Useful info to have on the forum. God knows what you would have written if you hadn't been tired!
Rich
Re: Rear Brake Sticking
Nick, have a word with Lewis while you are at the Grand Prix, he sounded so dejected with the lack of performance of the McClaren in Spain.
Very unlike him, seemed like he was saying 'why bother'.
Very envious, you may not see so much as on TV but the atmosphere
is unbeatable.
Very unlike him, seemed like he was saying 'why bother'.
Very envious, you may not see so much as on TV but the atmosphere
is unbeatable.
uk kiwis- Registered user
Re: Rear Brake Sticking
Adrian,
No problem. Thanks for the offer anyway
Matt,
Thanks, great how to.
Nick,
I could come and pick the tool up from you or at least meet somewhere, it's a bit out of your way to drop it to all the way me on your day off.
Cheers
Steve
No problem. Thanks for the offer anyway
Matt,
Thanks, great how to.
Nick,
I could come and pick the tool up from you or at least meet somewhere, it's a bit out of your way to drop it to all the way me on your day off.
Cheers
Steve
StevePem- Registered user
Re: Rear Brake Sticking
Well it is good and seized. Even Nicks winder could not shift it.
I have not seen one in good condition but it looks to me like the seal is split? Should it be sticking out like that anyway? (see pics below)
Where is the best place to get an exchange caliper at a good price?
Cheers
steve
I have not seen one in good condition but it looks to me like the seal is split? Should it be sticking out like that anyway? (see pics below)
Where is the best place to get an exchange caliper at a good price?
Cheers
steve
StevePem- Registered user
Re: Rear Brake Sticking
Matt!StevePem wrote:Where is the best place to get an exchange caliper at a good price?
Rich
Re: Rear Brake Sticking
Yes Rich?
Clear to see the problem in the pic, the dust seal has perished allowing the water to get in and corrode the piston. It is repairable but will require a new seal kit of the dust cover seal and the inner fluid seal but its easier for most people to just get a replacement caliper.
Your get an exchange(give them your old caliper) at majority of motor spares stores and prices will vary from £60 up to £140 depending on the supplier. Second hand can be used but always check the dust seal is intact and that the piston moves freely.
Clear to see the problem in the pic, the dust seal has perished allowing the water to get in and corrode the piston. It is repairable but will require a new seal kit of the dust cover seal and the inner fluid seal but its easier for most people to just get a replacement caliper.
Your get an exchange(give them your old caliper) at majority of motor spares stores and prices will vary from £60 up to £140 depending on the supplier. Second hand can be used but always check the dust seal is intact and that the piston moves freely.
Matt Parker- Registered user
Re: Rear Brake Sticking
What is the best course of action to prevent the caliper sticking?
I am concerned about mine sticking when it is laid up over winter?
Should I spray the calipers with WD-40 when I put the car in to hibernation? I do always leave the handbrake off.
I am concerned about mine sticking when it is laid up over winter?
Should I spray the calipers with WD-40 when I put the car in to hibernation? I do always leave the handbrake off.
darrenzs- Registered user
Re: Rear Brake Sticking
Not much you can do really, make sure that the seals are intact and then apply some grease all around the seal around the piston to give more weather protection but if the car is gonig to be parked up, leave the park brake off, car in gear and chock the wheels. The rear brakes will corrode up badly on the disc faces and the calipers will become lazy but when the car is brought back into use, make sure the park brake level arm is well lubricated(wd40) and then work the brakes alot to scrub the brakes faces back in. Worst case you will have to strip the brakes down, sand the faces of the disc's and pads and work the caliper pistons in and out afew times.
Matt Parker- Registered user
Re: Rear Brake Sticking
Thanks Matt, and you're correct: the rear discs do glaze over with surface rust worse than the fronts.
I presume that is because the rear discs are less shiny?
Since new I have always thought there must be much more braking effort done with the fronts rather than the rears, as I rarely have any dust to wash off the rear wheels?
I presume that is because the rear discs are less shiny?
Since new I have always thought there must be much more braking effort done with the fronts rather than the rears, as I rarely have any dust to wash off the rear wheels?
darrenzs- Registered user
Re: Rear Brake Sticking
Finally sorted!
It seems there are two disc sizes on the ZS so exchange calipers are either £65 and upwards or £95 an upwards depending on which discs.
Of course, mine needed the more expensive ones. I was quoted £45 for fitting so decided against doing it myself and had the aircon gassed and a dodgy tyre seal fixed at the same time.
all in all £240 lighter than I was this morning but at least the brakes work, cabin stays cool and the tyre stays inflated. Well, at least I HOPE all the above is true
It seems there are two disc sizes on the ZS so exchange calipers are either £65 and upwards or £95 an upwards depending on which discs.
Of course, mine needed the more expensive ones. I was quoted £45 for fitting so decided against doing it myself and had the aircon gassed and a dodgy tyre seal fixed at the same time.
all in all £240 lighter than I was this morning but at least the brakes work, cabin stays cool and the tyre stays inflated. Well, at least I HOPE all the above is true
StevePem- Registered user
Page 1 of 2 • 1, 2
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