Any Advice, Part 2!

[Laird Scooby]

Originally Posted by Othen

Number 57 and special flied lice.

PS. If you wind both sides all the way back then the parking brake should adjust itself as you pump the hydraulic system up.

That's the one!

Only if the handbrake cable is completely slackened before removing the pads and only adjusted with feeler gauges after both sides have auto-adjusted using the footbrake as you describe Alan. It's the vital step almost everybody misses out and causes the "rings of doom" on the rear disc - next stage is rear caliper failure!

[loki_the_glt]

With my Zafira B it took longer to do the rear pads than all four corners of the Exxon Valdez:
1) undo handbrake cable;
2) unbolt caliper;
3) remove pads;
4) re-fit caliper;
5) wind piston back;
6) remove caliper again;
7) fit new pads;
8) re-fit caliper again;
9) adjust handbrake.

On the Valdez:
1) remove securing pins;
2) withdraw pads;
3) wind back pistons;
4) insert new pads;
5) install new securing pins;
6) re-centre pistons.

And the handbrake works better on the Valdez!

[Chris152]

On a more mundane level :-) does anyone know how we establish what type of calipers we have on the rear? According to Haynes there should be a plate somewhere in the boot with a code, but I can't find it!

[loki_the_glt]

The calipers are probably Lucas/Girling at both ends, although there might be ATE calipers on the rear. Only early cars, almost certainly with solid front discs, had ATE front calipers. There should be a plate on the B-pillar with the codes: 1 for Girling, 2 for ATE.

Remove a roadwheel and look at the method of pad retention: Girling calipers use an "R"-shaped clip on each of the retaining pins.

ATE calipers apparently need a special tool to re-align the pistons.

[Chris152]

Haynes says it's in the boot on a post-1981 estate model, which I can't find (tho I haven't lifted all the carpets), and there's no info plate on any of the pillars. I'll see if I can identify the R-shaped clip, but if that fails could it help if I post a pic of the caliper?
Pillars - is the front one (windscreen) A-pillar, middle B-pillar, and so on?
Thanks.

[Chris152]

Pic attached!

[Laird Scooby]

I can just about make out the R clips through the pad retaining pins Chris so looks like Girling to me. You'll need a pair of long-nose pliers and a pin punch to remove the pins.

The top R clip is fairly eay to see, camera angle doesn't help on the bottom one but i've circled the top one and where the bottom one should be.



I'd give it a wire brushing first to remove any loost rust, apply a little penetrating fluid to the pad retaining pins where they go through the caliper then pull the R clips using the long nose pliers.

Use a pin punch on the inboard end of the pad retaining pins and drift the pins out using a hammer on the end of the punch. The punch should be as close to the size of the pad pins as possible but slightly smaller - not so small as it dishes the end of the pin and not so big that it gets stuck in the caliper.

Remove the anti-rattle spring (the H-shaped spring that locates under the pad retaining pins) after the pad pins are out, withdraw the pads and anti-squeal shims (if fitted).

My idea of the G-Clamp may not work as well as i first thought as it looks like (from your picture) you have pistons in both sides of the caliper, it's not a single piston sliding caliper as i thought it would be.

Remove the rubber dust cap (assuming it's survived the past 30 ish years) from the bleed nipple and give it a wire brushing followed by some penetrating fluid around the nipple. Find the correct size ring spanner to fit the bleed nipple (often 8 or 10mm) and put the spanner on followed by the one-way bleed valve. Slacken the nipple by ~1/4 turn and use either the pad spreader or long screwdriver or similar to ease the pistons back into the caliper. Sometimes it helps to temporarily refit the thicker pad in between the other piston and the one you're working on to prevent that one popping out.

Once you have the first piston fully in, temporarily fit one of the new pads in front of it, remove the old one from the other side and push that piston back in too then close the bleed nipple.
Remove the temporarily fitted new pad so you have access to both sides of the disc for a file. Wedge the file in so it's acting on the edge of the disc where there will be a slight lip which you can see easily on your pic. Use a long handled screwdriver between two or three of the wheel studs to rotate the hub/disc while holding the file against the edge of the disc to remove the lip, repeat for the other side of the disc.

Clean the surfaces of the caliper where the pads move in them and now grab the new pads and the file. Go round the metal edges of the pads removing any burrs, drips of paint etc that may cause them to stick in the caliper. Apply some copper grease to the metal backs of the pads and on the edges where they make contact with the caliper - the old pads should have witness marks to indicate where they are.
If it had (or the new pads come with) anti-squeal shims, press one onto the copper grease on the back of the pad and smear some of the copper grease onto the mating face of the shim that meets the piston. Insert the pad into the caliper and repeat for the other pad.

Clean the pad retaining pins with a wire brush and smear copper grease on lightly. Fit the lower one first, ensuring it goes through the anti-squeal shim holes as well as through the pads - push it home finger tight. Make sure the hole for the R clip is at an angle you can easily refit the R clip.

Now refit the H-shaped anti-rattle spring, locating the bottom of it under the lower pad retaining pin. Now repeat the pad pin procedure above with the top one, ensuring you catch the anit-rattle spring under the pin both ends - a small screwdriver helps to push the anti-rattle spring down to make life easier.

Once both pad pins are in, refit the R clips, pump the brake pedal a few times to ensure it is firm and the pistons have moved in to take up the clearance.

Repeat all of this for the other side and finally once everything is back in place with new pads, check and top up if necessary the brake fluid reservoir under the bonnet.

If you find the pedal is spongey (not springy, new pads will make it springy until they bed in) then it would be advisable to bleed both rear calipers. There shouldn't be any air in them but it sometimes happens.

Other than that, give it a road test to make sure the back brakes work (reversing then hitting the brakes will show them to be working or not) and go and have a well-earned coffee/tea/beer/whatever - delete as appropriate.

I don't think i've missed anything, i'm sure others will soon pipe up if i have though!

[Chris152]

Brilliant Dave - thank you! We'll work through that together before we start.

Do we need brake pad anti-squeal lube, and should we get in anti-squeal pads in case we need them or are they usually OK? I don't even know if it has them fitted, but we don't want to get that far and have to stop, I'd rather buy some up front if they might be needed.

[Laird Scooby]

Originally Posted by Chris152

Brilliant Dave - thank you! We'll work through that together before we start.

Do we need brake pad anti-squeal lube, and should we get in anti-squeal pads in case we need them or are they usually OK? I don't even know if it has them fitted, but we don't want to get that far and have to stop, I'd rather buy some up front if they might be needed.

Anti-squeal shims are optional Chris, if they're fitted or the new pads come with them fit them, if not just apply copper grease to the metal back of the new pads after deburring the edges with a file. That should prevent any squeal unless you get a bit of grit trapped between the pad material and the disc.

[loki_the_glt]

Originally Posted by Chris152

Haynes says it's in the boot on a post-1981 estate model, which I can't find (tho I haven't lifted all the carpets), and there's no info plate on any of the pillars. I'll see if I can identify the R-shaped clip, but if that fails could it help if I post a pic of the caliper?
Pillars - is the front one (windscreen) A-pillar, middle B-pillar, and so on?
Thanks.

You're correct about the pillar nomenclature. A-pillars are the windscreen ones; B-Pillars are at the back of the front doors; C-Pillars are where the back doors latch on a four-door vehicles and the D-pillars surround the tailgate.

The photo is of a Girling caliper, as LS has stated. The ATE calipers use a pin with a rotating collar that corrodes into the fixing hole in the caliper and will only go in in one direction (and probably never come back out). (Speaks the voice of experience from then Exxo Valdez.)