Diy: Dummies Guide To Changing Aygo Front Brakes

[adilmon]

...Bolt the wheel back on, lower the car and you're done. The tightening torque is 103Nm, which is very tight. Tighten the opposing Bolts (eg, left-right, top-bottom)...

Hi,

Just an update on the Apec pads and discs: I've done about 1,000 miles since the change and I'm quite pleased with the braking performance. I know it's not exactly scientific , but from the feedback i get from the pedal I would conservatively estimate the stopping power has improved by about 15-20%. I've made one emergency stop and I could hear the ABS modulator at work a fraction of a second sooner than I would normally expect. In any case, I now feel the original Bosch brakes are better suited to cars without ABS because the braking comes along in a more gradual fashion. As it happens though, all Aygos (or is it Aygii) have ABS as standard.

As for disc wear, I'll have to clock up a few more miles before I can report on that... Interim, I might have a go painting the calipers red.

[DangerMouse]

Just noticed some really cheap Discs and Pad on eBay - £50. This seems to be half the price of Toyota parts!

Anyone have experience of these?

[rgvsean]

Just noticed some really cheap Discs and Pad on ebay - £50. This seems to be half the price of Toyota parts!

Anyone have experience of these?

I paid £73 for an EBC set (discs and pads) and am very happy with them over the std items.

I would not risk myself with e-bay specials to save £23 to be honest.

[DangerMouse]

I paid £73 for an EBC set

Do you have a web address for these, I might follow the guide and sort them out myself as the prices I have been quoted are £150+

[Cokeman]

One thing to remember though, that I can't see mentioned here, is that when the pistons are pushed back in, the brake fluid in the system is also pushed back into the brake fluid reservoir on the master cylinder. Make sure that you check it when pushing back in so that excess brake fluid is not ejected through the top all over your paintwork. Then, as Orry says, make sure you pump the brake pedal to reset the pads before you drive off or you'll get to the first corner and you'll poo yourself!

[rgvsean]

Just take the lid of the reservoir and place a large rag around it.

Dangermouse: http://www.brakes4u.co.uk/

[adilmon]

Just an update: After 15,000 miles with Apec pads and discs I'm still pleased. When cold, they work better than the OEM discs and don't rust up nearly as much when not driven for a while. The disc wear is about the same rate as the OEM discs, but the other differences make it worthwhile.

I might try Rossini discs next. I've heard good things about them. Hoping that Diamond Black make them soon though

[Zaaro]

Any chance an admin can add this to the Aygo knowledgebase page?

[Projectzip]

Not wanting to sound ungrateful as I just used this guide to change my brakes.

The Bolt holding the disc on is a T30 not a T25 I used a T25 first and nearly cocked up the head!

The corrison may make you think its a 25 but its a 30, at least on my aygo!!

[adilmon]

Very glad you found it useful :)

Good point about the bolt size. Mine's definitely a T25 (2006 Aygo), but you should always check. It's better they use the larger size since the corrosion does means more force is necessary.

I'm nearly due for another change. I'll try another brand and report back. I don't think I'll change the brake fluid just yet though.

[Jamesbelfast]

Always remove the cap from the master cylinder before replacing brake components.

If using a G-Clamp to retract the caliper piston place one of the old pads friction side down against the face of the piston - this reduces the risk of damaging the piston and saves an awful lot of winding and rewinding of the clamp. Also open the bleed nipple to allow the fluid to escape. Allowing it to be forced back into the master cylinder is not a good idea especially if the vehicle has ABS as the control valves inside the ABS control unit don't like fluid travelling in the wrong direction. I have personally seen both Toyotas and Hondas give ABS problems afterwards - rare I admit but should it happen it is a very expensive repair. Plus forcing fluid back into the master cylinder on rare occasions can cause seal failure and there is no point in forcing dirty or cantaminated brake fluid back into the master cylinder. I use a small soft brass wire brush to remove any corrosion fron the brake pad housing and if necessay place the pad carrier in the vice and give it light rub with a file. Again if the face of the caliper piston is corroded it may not apply force equally across the back of the pad - so in some cases it may be necessary to clean the piston face with light emery or a file before retracting the piston. During assembly the pads should insert easily by hand - if force is required then something is amiss.

I have used APEC pads, etc for around 10 years and as yet have had no problems.

One word of warning though!! I emailed the APEC technical Manager for advice regarding copper grease (or anti-seize compound as it properly called). His reply was under no circumstances to coat the backs of the pads with copper grease and in fact if done so will invalidate any warranty. Most decent mechanics now refrain from such practice.

For obvious copyright reasons I am not able to publish his reply but I am fairly sure if anyone wishes to email him he may be only to willing to give advice.

Take your time when working with brakes and it helps to take a few pics or make a simple drawing before dismantling - this helps during re-assembly.

Remember brakes are like your best friends - you miss them most when they ain't around so if in doubt seek professional help.

[GIDDLEPIN]

Any chance an admin can add this to the Aygo knowledgebase page?

Started a "Hints and tips" it the "Important Topics" section. ;)

Anyone wanting to add items to this please send me a PM with link

Les

[Unklian]

Always remove the cap from the master cylinder before replacing brake components.

Also open the bleed nipple to allow the fluid to escape. Allowing it to be forced back into the master cylinder is not a good idea especially if the vehicle has ABS as the control valves inside the ABS control unit don't like fluid travelling in the wrong direction. I have personally seen both Toyotas and Hondas give ABS problems afterwards - rare I admit but should it happen it is a very expensive repair. Plus forcing fluid back into the master cylinder on rare occasions can cause seal failure and there is no point in forcing dirty or cantaminated brake fluid back into the master cylinder.

Oh Yes!

A friend pushed the brake pistons back to fit new pads without opening the bleed nipple.

The rush of brake fluid into the master cylinder inverted the lips of the brake master cylinder piston.

(Turned it inside out). After a lot of head-scratching and finding it impossible to get

a good pressure when braking, he worked out what the problem was.

A Passat Estate, he had to buy a complete master cylinder (£170.00).

I now always push brake pistons back with the bleed nipple cracked.

Okay, you lose a bit of fluid, but buying a bit of brake fluid for topping up as the pads wear could possibly save you

much more money in the long run.

Ian.

[GIDDLEPIN]

Always remove the cap from the master cylinder before replacing brake components.

Also open the bleed nipple to allow the fluid to escape. Allowing it to be forced back into the master cylinder is not a good idea especially if the vehicle has ABS as the control valves inside the ABS control unit don't like fluid travelling in the wrong direction. I have personally seen both Toyotas and Hondas give ABS problems afterwards - rare I admit but should it happen it is a very expensive repair. Plus forcing fluid back into the master cylinder on rare occasions can cause seal failure and there is no point in forcing dirty or cantaminated brake fluid back into the master cylinder.

Oh Yes!

A friend pushed the brake pistons back to fit new pads without opening the bleed nipple.

The rush of brake fluid into the master cylinder inverted the lips of the brake master cylinder piston.

(Turned it inside out). After a lot of head-scratching and finding it impossible to get

a good pressure when braking, he worked out what the problem was.

A Passat Estate, he had to buy a complete master cylinder (£170.00).

I now always push brake pistons back with the bleed nipple cracked.

Okay, you lose a bit of fluid, but buying a bit of brake fluid for topping up as the pads wear could possibly save you

much more money in the long run.

Ian.

Your friend must have been very unlucky Ian.

When applying the foot brake fluid is compressed into the piston cylinders and when the brake is released it will automatically return to the master cylinder, the only time I have seen reversed seals is when a pressure bleeder has been used incorrectly, this indeed reversed the seals and caused a problem, compressing pistons slowly will not reverse seals and as has been mentioned the worst thing that can happen is that the reservoir will overflow which is more messy than dangerous.

However: anyone trying yo use the method of cracking a bleed nipple must be aware that you will more than likely get air into the system which will at best make your brakes very spongy or at worst leave you with a hefty repair bill when you can't stop.

[Unklian]

Always remove the cap from the master cylinder before replacing brake components.

Also open the bleed nipple to allow the fluid to escape. Allowing it to be forced back into the master cylinder is not a good idea especially if the vehicle has ABS as the control valves inside the ABS control unit don't like fluid travelling in the wrong direction. I have personally seen both Toyotas and Hondas give ABS problems afterwards - rare I admit but should it happen it is a very expensive repair. Plus forcing fluid back into the master cylinder on rare occasions can cause seal failure and there is no point in forcing dirty or cantaminated brake fluid back into the master cylinder.

Oh Yes!

A friend pushed the brake pistons back to fit new pads without opening the bleed nipple.

The rush of brake fluid into the master cylinder inverted the lips of the brake master cylinder piston.

(Turned it inside out). After a lot of head-scratching and finding it impossible to get

a good pressure when braking, he worked out what the problem was.

A Passat Estate, he had to buy a complete master cylinder (£170.00).

I now always push brake pistons back with the bleed nipple cracked.

Okay, you lose a bit of fluid, but buying a bit of brake fluid for topping up as the pads wear could possibly save you

much more money in the long run.

Ian.

Your friend must have been very unlucky Ian.

When applying the foot brake fluid is compressed into the piston cylinders and when the brake is released it will automatically return to the master cylinder, the only time I have seen reversed seals is when a pressure bleeder has been used incorrectly, this indeed reversed the seals and caused a problem, compressing pistons slowly will not reverse seals and as has been mentioned the worst thing that can happen is that the reservoir will overflow which is more messy than dangerous.

However: anyone trying yo use the method of cracking a bleed nipple must be aware that you will more than likely get air into the system which will at best make your brakes very spongy or at worst leave you with a hefty repair bill when you can't stop.

Apparently, Where the brake piston is in the master cylinder,

it is in a parrallel sided bore. normally, the seal lips can't turn inside out.

To aid assembly (I presume) there is a small tapered lead into the cylinder.

Forcing the brake fluid backwards, pushes the piston *just* far enough backwards into the tapered portion

so there is room for the seal to invert.

The real unlucky part:- Normally, it would be a case of taking the piston out of the cylinder,

correctly positioning (or replacing) the seal and reassembling.

On the passat, After everything is factory assembled, a blanking cap / seal is cold-rolled

into position rendering the master cylinder a sealed unit.

"Sorry Sir, It's a sealed unit. BEND OVER..........£170.00 Please"

As you rightly say, it's a really rare thing. Probably impossible on most cars.

It's just made me a little paranoid. :D

Ian.

[Jamesbelfast]

When depressing the caliper piston with the bleed nipple open connect a small bore pipe to the bleeder and allow the excess brake fluid drain into a jar with about an inch of fluid in the bottom - this will minimise the risk of air getting into the system - also prevents all that messy spillage.:)

[adilmon]

Dudes, keep it simple. I don't recommend touching the bleed nipple unless you're prepared to bleed the system. The dummies way I showed works fine, but thanks for all the extra tips.

If the abundance of detail has put you off trying this, have a go at it shortly before you're due a service or MOT and get them to check your work. It really isn't that complicated

[johnhrh]

Hi, just found this post, its a good one but take it from me, never get under a car without some form of support just in case the jack gives way. One of my neighbors sons did that and cost him his life, jack gave way and the car crushed him to death.

regards

johnhrh

[KPARRIS-JONES]

Great work.

Would be worth moving this to the How To: section. ;)

[SRsmithy]

just a little tip, never use copper grease on the drive flange, ive been a mechanic 4 11 years and found it gives u brake judder in some cases.

the drive flange has to be clean and free from grease and rust, use a wire brush or emery cloth to clean the face.

never use grease on the wheel nuts as these wont torque up correctly and will come loose

[Toyota-Alan]

Thanks to the advice on this site, I have managed to save over £200. My local dealers wanted £350, for the job,

I put on Mintex Discs and pads at £77. and had purchased a set of star drivers 17.00, I had T25 but you've guessed my B car had T30.

The hard bit was plucking up the nerve, I've not used my tools for 20 years(when I was younger). Suppreising how unemployment and divorce forces you to change.

Thanks to you all.

Alan

[toyomaz]

I agree, EBC make excellent products, i have used their products many times previously and they also have a 1st class technical support service via thier website "contact us" tab.

http://www.ebcbrakes.com/index.html

Here is a quick ebc brake doctor / info guide from a reseller..EBC also say NO to copper grease it seems..the debate will go on...

http://www.brakes4u.co.uk/brake_do.asp

Red rubber grease is a very good idea on rubber piston seals/boots and stops them from going hard/brittle...also wipe over your cv joint boots with a very small amount while you have the wheels off !

http://www.opieoils.co.uk/p-999-fuchs-renolit-red-rubber-grease-grease-for-use-on-elastomers.aspx

[Unklian]

Changed my front discs & pads yesterday for EBC ones.

Read through this "How-to" to find the torque settings.

Just a suggestion to make things easier.

Before removing the caliper & holder,

tackle removing the T25 / T30 Disc retaining screw.

At this stage, you can stop the disc turning very easily by

inserting a screwdriver into the disc vent slots and, as

you unscrew the screw, the screwdriver will stop against

the edge of the caliper holder, preventing the disc rotating.

Also, If the disc is stuck fast on the hub,

there are 2 holes provided (M8). Tighten a couple of bolts into these and Hey Presto!

The disc is pulled off without any hammering / swearing. It's what those holes are for!

(There are a couple on the rear drums too).

Ian.

[jjj_aygo]

If only I knew about !Removed! bolts into those holes!

I resorted to drilling out my positioning screw it was that corroded not even an impact driver would free it!

Then I beat the :censor: out of the disc to get it off! haha

great pic and advice... cheers!

[tonydew]

Important.... You NEED A T27 Torx bit to remove positioning screw (Not a T25)