2001 1.8 - Brake caliper - mikeymike
Hi there, (1st post here) I have a Zafira 1.8, 2002. I changed the rear pads 9months ago and had some trouble pushing back the pistons with the proper tool. All seemed ok till this week when the brake and wheel overheated due to the pads catching. The following days it was back to normal with no heat. I've stripped it 4 times today and pushed back the pistons which are nice and free with the proper tool.
The pads are free in their slots but when i apply pressure the pistons move and out but will not retract leaving the discs party clamped. I've cracked both ends of the flexi hose to release fluid but pistons remain clamped. handbrake cable is free. I'm assuming now I have to replace the caliper as the internal adjustment parts are not allowing the piston to retract slightly to release the disc. The wheel heats up after a couple of miles. Any help would be appreciated before i spend my hard earned cash !
Mikeymike

Edited by Dynamic Dave on 26/01/2008 at 19:38

Brake caliper - Ruperts Trooper
Astra-G (mk4) and therefore Zafira-A which is based on the Astra have a problem with the Bosch rear calipers seizing. These were replaced in production with Lucas rear calipers.

Remove the pads from the caliper, thoroughly clean everything specifically the surfaces along which the calipers slide in their holder. Reassemble using coppaslip.

If that doesn't work you may need to source some Lucas calipers.
Brake caliper - mikeymike
Hi there, they are Lucas calipers. I've stripped and reassembled 4 times with the same result. All seems free till I press the brake pedal. Pads are free in the spring retaining plates. By releasing fluid it proves there is not a hydraulic restriction but looks mechanical and internal. Pistons are not corroded as i've peeped under the dust cover.
Prices quoted are £80 - £120 each caliper. I've talked with a vauxhall mechanic who says it is likely to be the caliper and if i booked it in that is what they would do first. He said he had not had to change many of these over the years. Does anyone know exactly how it works inside?

cheers for the reply.
Brake caliper - mfarrow
If you're worried about the cost might it be worth trying a service kit (circa £15). It sounds like you've exhausted all other routes.
Brake caliper - mikeymike
Not just the cost - I'm just frustrated that i can't see the problem as i can't work out what goes on inside. If I can get it sorted for £80 that will have to be ok as i need the car on the road. I'd not heard of a kit? what does it comprise of ?
cheers
Brake caliper - mfarrow
I'd not heard of a kit? what does it comprise of ?


That I don't know - see www.brakeparts.co.uk
Brake caliper - Chris Willstrop

I've had same issues with my Zafira & daughters Meriva.

I tried stripping down, cleaning, lubricating to no avail.

The piston is threaded onto a rod up the middle &screws

itself out as the pads wear. I think that rod is on a cam

operated by the handbrake cable

I cannot work out why its binds on the disk after use.

All i've seen is the handbrake lever not returning to

its stop every time.

Just change the caliper mate. £70 exchange from Eurocarparts.

Seen them on Ebay for £48 though !!

New caliper will cure it mate. Not worth messing about

with ??

Brake caliper - hardway

Calliper mech is there to "Take up the slack" from wearing friction material.

It's actually the piston/calliper seal that distorts under pressure only a small ammount then "relaxes" back to normal shape acting as a spring if you like to pull the piston slightly back into the calliper.

I'd fit a new piston seal and lube it with "Red rubber" grease on build up.

Brake caliper - edlithgow

Its sounds like you dont mean you stripped the calipers when you say you stripped the calipers. "Peeping under the dust cover" does not necessarily cut it. If you strip something you take everything apart and clean and lubricate it, including, in this case, removing the pistons and cleaning out the piston bores.

Sometimes its just the caliper pins sticking, but by no means always, so you might have to do the whole thing

I had the same situation as you describe with my Daihatsu, and thats what it took. Pistons were sticking in the bores. Was difficult for the first one because I didn't know to ignore the prevailing Internyet advice (to blow them out with compressed air) and just use the brake pedal. Second one went much quicker. Cleaned up nicely.

www.honestjohn.co.uk/forum/post/index.htm?t=113432

Thats a different car though. I dunno anything about special gizmos on the Zafira.

Edited by edlithgow on 21/02/2018 at 14:51