Brake piston seal is not pushed back

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Hello everyone,

I am trying to replace brake pads on my Nissan Qashqai and when I pushed the piston back I see that it's seal is not perfectly moved back. Please see the image below:

20150106_151341.jpg


I tried to gently push it to it's place (by hand) but it seems like it does not stay there.

What are my options?
 
You'll be fine!
smile.gif


As long as the seal IS NOT torn, it fine. It doesn't have to be perfect. Although I do know what you mean!
 
Thanks. I am actually now thinking if I should put the old pads back and this will "aligh" correctly.

Your post put some hope into me
smile.gif
 
I like to have the seal retracted the way that is is intended to be, with the proper accordian folds. I usually push the piston back out using the brake pedal until the boot is fully extended. Be very careful to not overextend it. I then carefully clean the boot with a rag dampened with a rubber safe cleaner, 303 in my case. I gently pull the boot out of the groove in the piston and reseat it, making sure that it is properly seated. I then restart the the procedure pushing the piston back in. This time I stop about 1/4 of the way in and inspect the boot. I gently pull or pry the boot out of the piston groove to "burp" any trapped air out. I continue pushing in the piston, sometimes needing to stop and gently use the rounded end of a machinist's ruler to push in/manipulate the boot at the offending area. It usually pops in the correct way after a try or two. I'm not sure if its trapped air or just stubborn rubber.

Good luck. Be patient. DON'T poke a hole or tear the boot.
 
Thanks guys for you help.

I did put a new pads and when I was locking the caliper on a brake pad I used a long and dull metal wrench to move the boot into it's place as caliper was closing.

It took some time but I finally did it in a right way and I made sure it was not trapped between pad surface and piston - that could tear it apart.

I am surprised I got this problem on Nissan, as just recently I was doing the same on my Peugeot and it worked well on both pistons. On Nissan I got this problem on both pistons. Surprising considering the fact that Nissan is 3 times more expensive than Peugeot.
 
The '01 Lexus in my signature has or had this same issue with 1 or 2 of the pistons seals/boots. I noticed this when I did the first brake job several years ago. I have done 3 brake jobs in this vehicle and not an issue with any of the calipers in 14 years. They all work as they should.
 
Thanks for your comments, especially to 'Char Baby'. Your comment cooled me down and instead of putting back the old pads I went again to garage and gently put the new pads
smile.gif


I took today the car for a drive and it works as expected. Will see on my next brake pad change if boot dust will be torn or not.

But so far it is OK.
 
Yes, it does seem a bit excessive in your case. Please do what you feel is the best for your situation. Mine were not that bad nor, do I have any issues today.

I did replace one caliper recently on my daughters Mazda 3 in my signature due to a torn boot but prior, it was not giving any issues and had always retracted properly. Why it had torn, I don't know but, the piston had seized so, I changed the caliper.
 
When changing pads, you have to push the piston back in....should this be done with the bleeder open? I thought i read somewhere that it did, but most or all my pad replacements in the past i just used my fingers to push the piston in, but it is so tough, i bought a big c clamp for next time.



Volodymry, nice bike. I had a couple of thundercats in the past and was going to get back into sportbikes and was loving the F4i, as the RR is to track focused. But then i took a motorcycle course and saw a photo of a XR750 and that got me looking into domestics.
 
Originally Posted By: mjoekingz28
When changing pads, you have to push the piston back in....should this be done with the bleeder open? I thought i read somewhere that it did, but most or all my pad replacements in the past i just used my fingers to push the piston in, but it is so tough, i bought a big c clamp for next time.



Volodymry, nice bike. I had a couple of thundercats in the past and was going to get back into sportbikes and was loving the F4i, as the RR is to track focused. But then i took a motorcycle course and saw a photo of a XR750 and that got me looking into domestics.


Don't do it with the bleeder open, there's a chance of sucking air in. Do it with the brake fluid reservoir cap removed, to stop air getting in and to avoid trying to compress the fluid.
 
mjoekingz28,

Originally Posted By: mjoekingz28
When changing pads, you have to push the piston back in....should this be done with the bleeder open? I thought i read somewhere that it did, but most or all my pad replacements in the past i just used my fingers to push the piston in, but it is so tough, i bought a big c clamp for next time.


There is a lot of discussion about this. Some people say that if you do not open the bleeder valve when you push the piston back, the fluid travels reverse direction and the master cylinder seals may "flip" resulting in total loss of braking. You can find in google that there are some cases like these with GM cars, mainly Opel (in Europe).

I have two Haynes manuals for both my cars (non GM) and in both manuals it is recommended to open the bleeder valve and put a hose on the brake line when pushing the piston back. That is the way I do it, but I cannot say I am experienced DIY mechanic. I am simply enthusiast who does DIY from time to time and I am trying to protect master cylinder of my cars
smile.gif


For actual pushing the piston I am not using the fingers even if I open the bleeder valve. I bought on Amazon the expander tool for 5 $ and I am happy about it. If you are interested, I can share with you the link, but it is easy to find. The thing is, if you are opening the bleeder valve you need to quickly push the piston so that air does not get sucked in, so the tool really helps to do this without too much hassle.

Originally Posted By: mjoekingz28

Volodymry, nice bike. I had a couple of thundercats in the past and was going to get back into sportbikes and was loving the F4i, as the RR is to track focused. But then i took a motorcycle course and saw a photo of a XR750 and that got me looking into domestics.


I am glad you bought XR750 since maintaining F4i or RR is a PITA
smile.gif
Before F4i I had Honda CB 400 SF (naked bike) and it was much simpler to maintain. So if I could go in past and instead of F4i simply buy Hornet or Bandit I would do it. Harley is a nice choice, plus I think it is important to support domestic products and you are always sure you can get spare parts without too much of overpricing.
 
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