C5 X7 front brake caliper

[aerodynamica]

Season's greetings all, hope you're having a nice time.

My C5 has been generally good this winter - started every time on the button in -8 degrees and defrosts quick enough (apart from the washer jets... WHY? citroen..) anyway the dreaded front brake caliper is sticking again.. It's the front left. I am wondering before I get into the grimy bits if there is a known problem with C5 calipers? Am I looking at seized sliders or the actual piston. If it's the sliders does anyone have access to the part number? Could anyone confirm the right type of piston rewind tool for the C5 because you get different designs coming up when you do a search.

[myglaren]

Early C5s certainly had. Mainly due to the handbrake mechanism corroding and also corrosion of the handbrake cables in their tubes.
The last time I had new calipers, cables and tubes and had them pack the tubes with grease to keep moisture out to inhibit the corrosion.
Caught early they can be freed up but it did appear to be a rather short-term fix.

X7s may be different though, never had one.

[citroenguy]

C5 x7 has normal "run off the mill" ATE brakes, which means exposed slide pins made out of stainless. They are re-usable, just some fine grit sand paper andthey'll be like new

Seizing pistons is uncommon on such a big car. But could be at fault if the brake fluid hasn't been changed in a decade..
More probable is rust or schmuts on the break pads where they meet the caliper holder.

NO copper antiseize or similar on the slide pins! Only silicone grease or red rubber grease.

[GiveMeABreak]

The fronts don't require the piston to be wound back on this vehicle. You use Facom pliers (D60.A) like these:

[MattBLancs]

Handbrake operates on the rear calipers on an X7, thread title mentions front caliper?

Piston is conventional on the front, isn't it? So a g-cramp would do to push it back in, no need to rotate and shove?

[MattBLancs]

Glad we didn't disagree with one another!

[GiveMeABreak]

Yes, only wind back on the rears Matt.

[aerodynamica]

Thanks all, I wasn't aware that the rear calipers needed winding but the fronts didn't.. good to know!

Yes, I will have to have a proper look now to see what's happening - it's likely the brake fluid has not been changed looking at the state of the front bleed nipples..

[KennyW]

Graeme,
You can buy a refurb kit for these brakes. I had a sticky caliper a couple years back and refurb'd same no problems since. Piston refurb kits is between £15 to £20 can't remember if it came with new sliding bolts or not. Kits can be bought from Big Red, Brakes International etc

Kenny

[aerodynamica]

Had a look at this today, the sliders seem fine and I think the piston was sticking. Some cleaning of the whole caliper and a few strategic careful applications of wd40 and some whacks each way with a lump hammer freed it up good. Longer term I think both front calipers will need 'done ' maybe before mot in April.
Thanks for the help as usual