Hi all,
I am changing the pads and discs on my mk3 fiesta xr2i but does anyone know an easy way on how i push the cliper piston back into it's bore to accomodate the thicker pad.
I know it shouldn't really be done like this and bleeding some fluid is better but i am following haynes.
Also I am having trouble tearing off the paper to reveal the adhesive for the outer pad, I just cannot seem to find where the adhesive/backing paper is, is there an easy way to do this also, they are motorcraft pads.
Many Thanks as always
Steveo
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sorry forgot to ask also what is the small raised ball on the back of the outer pad, ie the one with the adhesive, used for?
Thanks
Steveo
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I'm not familiar with the car, but some have a caliper that you have to screw in using an allen key inside the hollow piston or in the caliper casting, it may be woth a look if no-one else answers.
Are you sure it is adhesive and not an snti-squeal shim, I have never had adhesive backing on any of my cars.
Good luck!
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On cars I am familiar with, not this one though, it is simply a matter of levering it back in using a large screwdriver or a tyre lever.
BUT:
1) Be very careful not to damage the lip of the piston, or the disk. Try and insert some kind of bridge to lever against, or the old pad.
2) There is a school of thought that advises loosening the bleed nipple to release the excess fluid, rather than simply pushing what may be old dirty fluid back up into the master cylinder. This can cause the seals in the MC to fail.
3) If the pistons are very hard to press back it may indicate that they are seized, or partially blocked with deposits or corrosion inside the caliper chamber. I have often successfully freed a seized piston by levering back a little, then pressing out again using the pedal. Keep repeating this action a bit at a time, gradually increasing the amount of easy movement. When finally free it would be worth bleeding off some fluid to expell any dirt you have loosened. Ideally of course flush out the whole system.
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i have a couple of different size G clamps that i use to push the calipers pistons back.
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Not heard of adhesive on back of pad before..It may be anti squeel coating to replace shims?.If so. dont remove
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Steve
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Buy a 'G' Clamp from local hardware store (approx £5), will wind back all calipers. Be sure to remove fluid bottle lid before winding in caliper.
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When I've done this in the past I've:
1. Release the cap on the brake fluid reservoir
2. Place a thin piece of wood against the piston
3. Use another piece of wood to lever the piston back into the calliper. It's usually stiff at first but once it starts moving it's pretty easy
4. The stuff on the back of the pads is probably something like Copperease to stop brake squeal.
Andy
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My actions mirror Andy P (I use the wooden handle of a small hammer.. but I also undo the bleed screw (and attach a bleed tube leading to an empty jar) as the whole exercise is then much easier.
madf
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ok firsth thing first
1. dont forget you can only mess with your car in the rain
2. and the wife having her monthly (so she will be on your case)
3. make sure the kids are hanging around
4. put the caliper on something had maybe even the dics rim and edge it out with a hammer handle. dont even think about doing it without axlestands.
5. take off the top of the reservor, to relieve it a bit, and DONT forget to put it back on of course
i did mine at the weekend with a mate and when you take the old pad out and compare it to a new one, you think oh no theyve given me the wrong one that will never go in there!
6. vvv important , cut your hand badly
at this point they will start to be levered back but watch the seal dont catch that with anything.
7. put new one in , euphoria for 1o mins real sense of accomplishemt , be nice with wife and kids, and she will pull her face with you and not share in any of your joy.
8, put it all back , go round to other side and repeat it, only 15 times quicker this time
9. lower car down, dont forget to pump pedal for 20 sec and then start car and do it again.
10. rain stops, put wet tools away so they will be ontheir way to rusting for next time. go in and be happy with kids but wife will still be in one with you for rest of day,
11. go in work and brag about how easy it was.
dont anybody try and moan about this post this is exactly how it is. and you know it
!!
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First of all, I'm only familiar with VW's, but, with the rear brakes(only), on my Golf Gti and Passat, the piston has to be pushed and turned simultaneously, there is a special tool for this,(I bought one recently for about £15), previously, I used a "G" cramp,a socket and a pair of water pump pliers! Not entirely satisfactory! Spend £15, it wil be a good investment if your piston is of the push and turn variety.
I hope this is of some use to you.
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You forgot to mention the bit where a very important call comes in that means the cars is urgently needed half way through the job.
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Many Thanks for all the great suggestions as usual. The piston turned out not to be seized but just very hard to push back I purchased some G clamps and no problem. Now running new ford original disks and pads and thanks to my new Eziebleed new fluid as well! Thanks again.
Steveo
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I have Girling tool I have had for 20+ years, basically a length of tube with a handle and a 1" wide plate welded at right angles. You put the plate across the end of the piston and press down the handle and the plate rotatates and presses against the caliper frame and piston
Sorry, easier to draw than explain in writing, but you can still get them from other makers
Works on my Fiat OK, but reading the manual I find I should have rotated the piston as I rotated it. Can't see the reason, unless this is to prevent you turning the seal over, something which must be pretty difficult to do
Anyone there who can confirm?
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My Xantia has the handbrake mechanism on the front calipers. The piston has to be rotated back to re-set the handbrake adjusting system. The piston has a slot in it, and the pads a lug which engages with the slot to stop the piston rotating and let the handbrake system work.
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If it's the front discs then a G clamp will do - if it's not seized - but if it's the rear they need to be turned by an Allen key, a screw driver or special tool. My Focus rears would not screw back because of the excess pressure but I didn't know that at the time. The screw kept turning but wouldn't go back. So I took the piston off and put it in a vise. As the other one was the same I just opened the bleed nipple.
jim
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Quite a lot of companies make tools specially for the job. Draper do one (stock no. 52335) available online at £21.74 plus £4.90 next day delivery. It could work out cheaper in the long run than improvising.
Search for stock number 52335 on www.draper.co.uk
--
L\'escargot by name, but not by nature.
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I use one of those spring loaded ratchet g-clamps. ie similar ratchet mechanism to that used in sealant guns. Perfect for the job, and can be bought for around a fiver.
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Machine mart's website shows CHT268 Disc Brake Piston Spreader for £17.57 inc vat, it looks similar to the Draper.
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