Caliper issue

[Scott S]

In geneal terms of the brakes, my car are fine, the initial bite is good and stops great under 'normal' braking but when making an attempt to stop quickly there just doesn't seem to be anything 'extra' there.

I had a look at them today and all pads have plenty of meat left on them (rears are Ferdo branded, but didn't take the fronts out), the discs aren't too thin, however, the back of my discs (far more evident on the rear) look like the caliper hasn't been working properly.

Took the rear pads out to checked the movement of the piston, but the n/s caliper piston wouldn't go back in (couldn't find a 'G' clamp), in the end I just had to wind the piston back in so now my handbrake won't work properly on that side (going to get back at it next weekend).

I bled the system so going to see if that helps, but is it worth taking the calipers apart and freeing the pistons properly, or do I just find my G clamp and get the pistons to move in and out a few times, or do I just but new calipers?

 

[Scott S]

Anyone?

Are my calipers worth 'servicing', or do I get replacement ones (would only be looking for used ones)?

Have serviced mitsi calipers in the past to sell on and it has worked fine, but no experience with Renault ones.

*EDIT*

Just realised I have posted in the wrong section....... can this please be moved to the faults section? Please fee free to ridicule me...............

 

[Henry]

would probably have to compare to be sure there's a problem (not sure what you mean by the 'extra' not being there), but concentrate on the fronts (unless you've also got an obvious problem with the rears), as it's the fronts that do almost all of the work

from the sounds of it, guessing it's the fluid or the pads. (carefully) check the front pistons will pump out if you take the pads out

 

[Scott S]

By the 'extra', I mean, can't get the ABS to kick in. I wouldn't normally want to have it kicking in, but when I get a new car, I like to check it works fine (once bought a car with ABS that didn't work and the one previous owner's idea of a 'fix' was to take the bulb out of the dash).

Unless the ABS is being activated and it just isn't as obvious as it is in other cars I have had.

Rear caliper piston wouldn't go back in yesterday so rears need a little attention (although that could be due to me not having the right gear to get the piston back in). Changing the fluid yesterday has helped, it feels sharper now when hitting the pedal.

I did drive another two 172's when looking for one, but didn't try hitting the brakes hard so can't compare.

The car feels fine under normal and slightly heavy braking so there's nothing serious, but I just thought there would be more from 280mm discs when wanting to stop quickly.

My last three cars have had twin piston calipers with 276mm discs (two of them had braided lines as well so no 'balooning' of lines), so maybe I am just expecting a little too much? It still stops better than my lass' Punto.

 

[Scott S]

Pads are the next thing to try, might as well get discs as well. Brembo and Ferdo mix seems to be the most popular, so will probably go for that, unless I can find a big brake setup for sale.

After that, it's braided lines.

 

[Pitbull]

Unless the ABS is being activated and it just isn't as obvious as it is in other cars I have had.

It is very obvious when the ABS kicks in and also pretty easy to achieve. Find a quite road at 30mph and stamp on the stop pedal hard, it should kick in and vibrate the pedal alot.

 

[Scott S]

It is very obvious when the ABS kicks in and also pretty easy to achieve. Find a quite road at 30mph and stamp on the stop pedal hard, it should kick in and vibrate the pedal alot.

I assumed it would be like that, but haven't felt it yet.

Will try tonight on my way home, will see if the new fluid has helped.

 

[Cupster]

Seized caliper slider. I couldn't get my cup to lock up!!!

So seized I had to get another caliper. Regrease, refit and done.

Have a search, you will find a few threads on this.

 

[Dangerous_dave]

some second hand calipers on ebay i noticed earlier today...cant remember if it was all 4 or just rears tho.

good luck

 

[Scott S]

Right, some goood news, the ABS will now happily kick in

When changing the fluid yesterday, I did notice a few tiny bubbles, but the main thing was the fluid that came out of the fronts at first looked horrible. It took a canny while to get clean fluid through. I knew this would make a difference, but didn't think it would help as much as it did.

Probably never been changed in 5 years and 40k miles. Never mind, loads better now under heavy braking and pedal feels better under normal braking.

Thanks for the tips on the sliders and the calipers on ebay., going to take the front calipers apart to check the sliders (done this loads of times on the proton), will also lube them all up regardless of condition os I know it has been done.

 

[Cupster]

You will be able to stop on a six pence after this chap!

 

[Scott S]

Got the brakes sorted properly today, new discs and pads all round as well as braided lines and new fluid throughout.

Gave the calipers a good check over and they are fine, but the pads on the front and the rear weren't sitting 100% right and the fronts looked like cheap ones.

Loads better again. It's like a different car when slowing down.