V8V Brake refurb - possibly some tips
Discussion
To add my experiences to JonnyCJ,
https://www.pistonheads.com/gassing/topic.asp?h=0&...
and with apologies for my less than pristine suspension condition (yes I will do the excellent full suspension rebuild at some point!) I have just finished refurbishing all the brakes on my own V8V, 4.7 2009. There are lots of videos from Redpants and others, so this is additional tips that I have found or discovered…
Removing the calipers
It’s best if you can use the car’s hydraulics to push out the pistons as far as possible so I took out all the pads, noting on them with a sharpie where they had come from (eg F/NS/Inner) if the discs are staying on. Then I cut 8 squares of hardboard 100-110 mm wide to fit into the caliper to mimic very worn pads!! Then I pumped the brake pedal to force the pistons to move out without them popping out completely – if one pops out it’s game over for pushing out any others, as there will be no pressure. Check that all the pistons have moved to close the gap in all the calipers before removing any calipers. If they are stuck you have a problem and will need to send them off or buy new ones. Loosen the bleed screws whilst on the car with a socket – take care! If one snaps off, speak to someone BCS or similar, but quite possibly the end of the caliper for economic repair. They aren’t toooo bad new, about £900 for the front pair.
Take off the calipers and on the braided hydraulic lines screw on either M10x1 blank nuts or, as I did, 8mm nominal bore fuel line cut off to about 150mm length and blocked either with an expanding motorcycle earplug! Worked a treat. Soak the unions in penetrating oil for later. I didn’t want to empty the master cylinder so I used cling film under the cap.
Handbrake caliper
I used the ‘take the black-painted bolts out of the caliper body’ to split the caliper and it’s excellent! All comes off, pins and pads fall away and the disc is exposed. My caliper fixing bolts were stuck fast. Loooong spanners.
Removing and replacing discs
Draper impact driver to loosen stuck Torq retaining screws. A rubber hammer behind the disc and they come off, might need more penetrating oil. New Brembo ones from AutoDoc, £80 each – I had tried to have them skimmed but that didn’t work out well. Stiff wire brush the rusty bits on the hub. Make sure absolutely clean and smooth, no bits at all to remount discs.
Caliper re-build and paint
I decided to clean and prep first, then remove pistons as chance of damage, then paint, then remove seals, then rebuild. Clean in a parts washer, abrade them thoroughly with 240 grit wet and dry. Clean and de-grease.
I made timber jigs to support the calipers, as they bolt to the hubs in a kind of radial way, the jigs allowed painting at all angles and firmly supported them during piston and seals change. For refurbing the fronts there is a standard kit for the front pair from Frentech on eBay. The rears I needed to order the pistons and seals, pins and pressure plate separately. For my rears, only a few pistons needed replacing and the pistons etc are available at the right size from Frentech – measure all dims with caliper guage. Carefully use screw drivers to prise out the old dust seals then pistons. And to remove the seals in the bores. Tissue to plug the piston holes, masking tape and more earplugs.
I used two-pack BCS caliper paint as I wanted to have high quality, heat-resistant paint and DIY. I wanted solid black but they didn’t have that and no sign of availability, so I went for their metallic grey gunmetal. If you like a ‘hewn from solid billet’ and a somewhat textured look then that’s fine but I would say have them spray any metallic paints if you don’t. It’d have been better to hand paint a solid colour, IMHO.
Painting tips
Everything at room temperature, good lighting and plenty of newspaper! The two-pack paint sets, but it takes AGES to set in the pot but not on the caliper so no need to hurry at all - really, take your time. First a thin coat on them all then WAIT at least 45mins, preferably and hour, before you start the second coat; the paint needs to have thickened so that it goes on glossy without the brush marks (this really works!) and is fine to apply for at least 2-3 hours. I used the timber jigs to let the paint dry with the flat Aston Martin face upwards to avoid any visible runs.
Assemble the innards of the calipers from the kit, very straightforward but put the dust seals onto the pistons before you fit them. I used a touch of the red rubber grease inside the pistons and metal-free anti-squeal supplied for the back of the pads, guides. Tiny amount of metal-fee brake grease on the pad guides and on the pad pins. So all new pistons and seals at the front, pins, pressure plates, pads at front and rear, and also a couple of pistons at the rear. Applied the transfer white Aston Martin from BCS, excellent quality.
Handbrake Caliper
Rewound the caliper pistons with a pair of C-clip pliers. Clockwise!! Parts are really hard to find for these calipers, Frentech supplied some brake pad pins, from a Range Rover, but they weren’t a perfect fit, so I cleaned up the old brake pad pins and pressure plates. New pads from Astonbits. BUT I had the caliper sliding pin rubber gaiters disappeared from the upper caliper sliders – just not there! After some proper measurement and referencing the original supplier’s catalogue, identified new rubbers from Frentech code B5130 and the handbrake calipers are sorted. Reassemble the handbrake around the disc, about 80Nm torque on the caliper body bolts.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Refit all the calipers to 30NM then 80NM, the rear ones I cleaned each brake hose union with a toothbrush and brake cleaner but could not free the union to spin on the hose so I spun on the caliper on, carefully without cross threading – not easy, lots of swearing but in the end both went on and then mounted the rear caliper with new bolts. Yes, it’s a few quid for new caliper bolts, to me it’s worth it! The fronts, I loosened the union from the hose and it was spinning on the hose after cleaning, so I mount the caliper first and then spin in the hose union. Much easier. Make sure the new bleed screws are all done up or all the fluid will gradually drain, not great.
Bleeding…
I used an EasyBleed, pressurising the system from a tyre at 20psi (they mean when they say no more!) and opening up the furthest outer bleed screw first to flush to fill and I can see the bubbles and when they stop. I bleed them as far as I can. Leave a few days and repeat. A couple more bubbles and the fluid is a bit pink as the red rubber grease is removed.
Handbrake self-adjusted for me, keep pulling it up and releasing it and after a dozen or so it settled down, ‘hand brake on’ light went off.
Drive carefully, bed the pads in by gentle driving and remember the pedal will be soft until this is done.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
and with apologies for my less than pristine suspension condition (yes I will do the excellent full suspension rebuild at some point!) I have just finished refurbishing all the brakes on my own V8V, 4.7 2009. There are lots of videos from Redpants and others, so this is additional tips that I have found or discovered…
Removing the calipers
It’s best if you can use the car’s hydraulics to push out the pistons as far as possible so I took out all the pads, noting on them with a sharpie where they had come from (eg F/NS/Inner) if the discs are staying on. Then I cut 8 squares of hardboard 100-110 mm wide to fit into the caliper to mimic very worn pads!! Then I pumped the brake pedal to force the pistons to move out without them popping out completely – if one pops out it’s game over for pushing out any others, as there will be no pressure. Check that all the pistons have moved to close the gap in all the calipers before removing any calipers. If they are stuck you have a problem and will need to send them off or buy new ones. Loosen the bleed screws whilst on the car with a socket – take care! If one snaps off, speak to someone BCS or similar, but quite possibly the end of the caliper for economic repair. They aren’t toooo bad new, about £900 for the front pair.
Take off the calipers and on the braided hydraulic lines screw on either M10x1 blank nuts or, as I did, 8mm nominal bore fuel line cut off to about 150mm length and blocked either with an expanding motorcycle earplug! Worked a treat. Soak the unions in penetrating oil for later. I didn’t want to empty the master cylinder so I used cling film under the cap.
Handbrake caliper
I used the ‘take the black-painted bolts out of the caliper body’ to split the caliper and it’s excellent! All comes off, pins and pads fall away and the disc is exposed. My caliper fixing bolts were stuck fast. Loooong spanners.
Removing and replacing discs
Draper impact driver to loosen stuck Torq retaining screws. A rubber hammer behind the disc and they come off, might need more penetrating oil. New Brembo ones from AutoDoc, £80 each – I had tried to have them skimmed but that didn’t work out well. Stiff wire brush the rusty bits on the hub. Make sure absolutely clean and smooth, no bits at all to remount discs.
Caliper re-build and paint
I decided to clean and prep first, then remove pistons as chance of damage, then paint, then remove seals, then rebuild. Clean in a parts washer, abrade them thoroughly with 240 grit wet and dry. Clean and de-grease.
I made timber jigs to support the calipers, as they bolt to the hubs in a kind of radial way, the jigs allowed painting at all angles and firmly supported them during piston and seals change. For refurbing the fronts there is a standard kit for the front pair from Frentech on eBay. The rears I needed to order the pistons and seals, pins and pressure plate separately. For my rears, only a few pistons needed replacing and the pistons etc are available at the right size from Frentech – measure all dims with caliper guage. Carefully use screw drivers to prise out the old dust seals then pistons. And to remove the seals in the bores. Tissue to plug the piston holes, masking tape and more earplugs.
I used two-pack BCS caliper paint as I wanted to have high quality, heat-resistant paint and DIY. I wanted solid black but they didn’t have that and no sign of availability, so I went for their metallic grey gunmetal. If you like a ‘hewn from solid billet’ and a somewhat textured look then that’s fine but I would say have them spray any metallic paints if you don’t. It’d have been better to hand paint a solid colour, IMHO.
Painting tips
Everything at room temperature, good lighting and plenty of newspaper! The two-pack paint sets, but it takes AGES to set in the pot but not on the caliper so no need to hurry at all - really, take your time. First a thin coat on them all then WAIT at least 45mins, preferably and hour, before you start the second coat; the paint needs to have thickened so that it goes on glossy without the brush marks (this really works!) and is fine to apply for at least 2-3 hours. I used the timber jigs to let the paint dry with the flat Aston Martin face upwards to avoid any visible runs.
Assemble the innards of the calipers from the kit, very straightforward but put the dust seals onto the pistons before you fit them. I used a touch of the red rubber grease inside the pistons and metal-free anti-squeal supplied for the back of the pads, guides. Tiny amount of metal-fee brake grease on the pad guides and on the pad pins. So all new pistons and seals at the front, pins, pressure plates, pads at front and rear, and also a couple of pistons at the rear. Applied the transfer white Aston Martin from BCS, excellent quality.
Handbrake Caliper
Rewound the caliper pistons with a pair of C-clip pliers. Clockwise!! Parts are really hard to find for these calipers, Frentech supplied some brake pad pins, from a Range Rover, but they weren’t a perfect fit, so I cleaned up the old brake pad pins and pressure plates. New pads from Astonbits. BUT I had the caliper sliding pin rubber gaiters disappeared from the upper caliper sliders – just not there! After some proper measurement and referencing the original supplier’s catalogue, identified new rubbers from Frentech code B5130 and the handbrake calipers are sorted. Reassemble the handbrake around the disc, about 80Nm torque on the caliper body bolts.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Refit all the calipers to 30NM then 80NM, the rear ones I cleaned each brake hose union with a toothbrush and brake cleaner but could not free the union to spin on the hose so I spun on the caliper on, carefully without cross threading – not easy, lots of swearing but in the end both went on and then mounted the rear caliper with new bolts. Yes, it’s a few quid for new caliper bolts, to me it’s worth it! The fronts, I loosened the union from the hose and it was spinning on the hose after cleaning, so I mount the caliper first and then spin in the hose union. Much easier. Make sure the new bleed screws are all done up or all the fluid will gradually drain, not great.
Bleeding…
I used an EasyBleed, pressurising the system from a tyre at 20psi (they mean when they say no more!) and opening up the furthest outer bleed screw first to flush to fill and I can see the bubbles and when they stop. I bleed them as far as I can. Leave a few days and repeat. A couple more bubbles and the fluid is a bit pink as the red rubber grease is removed.
Handbrake self-adjusted for me, keep pulling it up and releasing it and after a dozen or so it settled down, ‘hand brake on’ light went off.
Drive carefully, bed the pads in by gentle driving and remember the pedal will be soft until this is done.
Some great tips there MIke - I particular the one about removing the caliper whilst still attached to the brake flexi and pushing the piston out using the brake pedal.
Luckily I was replacing all my pistons with new Frentech pistons, otherwise using piston calipers can be a bit of a faff if you don’t want to damage the pistons.
Excellent thread and thanks for taking the time to post. One for the stickies Mr Mods ?
Luckily I was replacing all my pistons with new Frentech pistons, otherwise using piston calipers can be a bit of a faff if you don’t want to damage the pistons.
Excellent thread and thanks for taking the time to post. One for the stickies Mr Mods ?
Thanks both.
I completely painted the caliper, over the original white painted Aston Martin and applied the white vinyl decals that BCS sold me. They are expensive but I wanted them as good as possible. They say not to lacquer over them, so they are just stuck right on, hence me wanting the best!
The only issue I'd had before the rebuild was a bit of discolouration on the fronts due to a spirited drive at Silverstone, they had got hot. When I got them off the car, as Jonny found, the chrome plating was failing on many of the pistons after 12 years and 70,000 mile and some of the dust seals were looking a bit dicky. So no performance problems, just wanted to refresh them and fettle a bit!
I had just similarly refurbed the brakes on my C55 Mercedes and as I had learned some lessons (eg dangling the calipers from a bit of string or wire really won't work well) and understood the characteristics of the 2-pack paint, so I fancied a go!
I completely painted the caliper, over the original white painted Aston Martin and applied the white vinyl decals that BCS sold me. They are expensive but I wanted them as good as possible. They say not to lacquer over them, so they are just stuck right on, hence me wanting the best!
The only issue I'd had before the rebuild was a bit of discolouration on the fronts due to a spirited drive at Silverstone, they had got hot. When I got them off the car, as Jonny found, the chrome plating was failing on many of the pistons after 12 years and 70,000 mile and some of the dust seals were looking a bit dicky. So no performance problems, just wanted to refresh them and fettle a bit!
I had just similarly refurbed the brakes on my C55 Mercedes and as I had learned some lessons (eg dangling the calipers from a bit of string or wire really won't work well) and understood the characteristics of the 2-pack paint, so I fancied a go!
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