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Discussion Starter #1 (Edited)
How to change front brake discs and pads

Here is a 'how to' on replacing front brake discs and pads.

I did this on my Laguna 1 phase 2,but the basic principles are the same no matter what car your carrying this out on.

The first thing to do is remove the cap from the brake fluid reservoir.This will save you spraying brake fluid everywhere or damaging the master cylinder.Also,make sure the keys are in the ignition,but with the ignition off.If your car has ABS the pump could be damaged if you have the ignition switched on.



Next,remove the front wheels and put the car on axle stands.Work on one side of the car at a time,and turn the steering to gain easy access to the caliper.



Next,remove the lower caliper bolt.



To do this you will need a 13mm spanner on the bolt and thin headed 17mm open ended spanner to stop the inner slider from spinning.If you haven't got a thin 17mm spanner,then it is possible to use long nose pliers or molegrips.



Once this bolt is removed,pull the caliper up and then slide it off of the top slider.



It's a good idea to support the weight of the caliper by either tying it up to the suspension leg or resting it on top of something so as not to damage the flexible brake hose.

Next,remove the two brake pads......



Next,remove the two 18mm caliper carrier bolts.They will be reasonably tight.....



Once the carrier has been removed,the two disc holding bolts will need to be removed.It is best to hit the heads of them with a hammer before trying to remove them as they are T40 torx bit headed bolts and they have a tendency to round off.Hitting them with a hammer loosens the treads and makes them easier to remove.



Tap the disc away from the hub,and this is what your left with.....



Next,the hub face must be cleaned with emery cloth to make sure that it is flat and smooth.If this isn't done,then the new disc will warp causing brake vibration.Once cleaned it should be nice and shiny.:)



It is now time to fit the new disc.They are covered with an anti-corrosion coating and this needs to be removed before the disc is fitted.A special product is available for this job,but any solvent based product that evaporates will do just as well.Bolt the disc onto the hub using the two bolts removed earlier(recommended tightening torque,15Nm)....



Next,clean the faces of the caliper carrier which the pads touch.This will stop the pads sticking in the carrier.



Next,bolt the carrier back on and tighten the bolts to 100Nm.The pads can then be placed into the carrier.It is a good idea to grease the contact patches between the pad and the carrier,and between the pad and the caliper.This helps prevent the pads sticking in the carrier and also helps to prevent brake squeal.There are special products available to grease the pads,and copper grease should NOT be used!.Also,becareful not to get any of the grease on the disc face or the pad friction face......obviously,the pad friction face goes towards the disc.:)





Next you have to squeeze the caliper piston back into the caliper.This can be done a number of ways,but I tend to use a large pair of water pump pliers.You have to be gentle when pushing the piston back as it is possible to damage the seals in the master cylinder or the caliper if you try and push it back too fast.This is also why you remove the reservoir cap as the fluid you displace goes back to the reservoir and needs somewhere to overflow if nesseccary.



Once the piston is fully back,you are ready to re-fit the caliper.It's a good idea to grease the sliders before re-fitting the caliper,and make sure they are both free and easy to move.Slide the caliper over the top slider and push the caliper down making sure that the 'see-saw' springs on the pads are against the inner face of the caliper.



Tighten the caliper slider bolt to 35Nm and you are 50% of the way there...



You must now gently pump the brake pedal to bring the piston into contact with the new pads.Push up and down on the pedal slowly,not going beyond half the pedal travel,until the pedal goes solid.

Once you have replaced the other side,do the same and check the fluid level in the reservoir.Adjust the level to get it to the maximum level by removing some of the fluid by either soaking it up with some absorbant paper or using a syringe if you have one.Re-fit the cap,and if any fluid has leaked out,wash off with water.

This is only a guide,and if you are not confident with a set of spanners please don't attempt this job.Your brakes can save your life,so please becareful.If you do have a go at changing your own discs and pads,take your time and double check everything.

After fitting the new discs and pads,avoid heavy braking for at least 200 miles to allow the pads and discs to bed in.

I hope someone finds this usefull,and I will update it again tomorrow as I'm sure I've forgotten a few things........
 

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Leroy,I know the wheel bearings need swapping over on rear discs on the Clios and 19's,but not 100% sure about your Lag.....

If they are then it's worth spending the extra money and buying new discs with a new wheel bearing and ABS ring already fitted.It is very easy to damage the bearings and the rings when swapping them over.......
Whats the cost difference in the parts, I presume also to fit them in a DIY situation it would be alot quicker as well.

Regards

Otttoman

:)
 

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Replacing discs and pads

Excellent post Laggy - very well explained. I have done this job numerous times and I would like to add a few extra tips. Winding the caliper piston back in should be done very slowly and gently - ensuring you don't damage the edges or face of the piston. I use an old G-clamp (the type joiners use) and place one of the old pads (lining side against the piston) between the clamp and piston - this ensures the piston is pushed back straight with no risk of the piston being displaced sideways. Gradually turning the screw in the clamp provides enough pressure and prevents damaged knuckles. On cars with ABS and other electronic systems it is best to open the bleeder when retracting the piston - doing it this way minimises any risk to the controls systems. When going this far in replacing pads and discs I would advise the brake fluid be changed. - most car manufacturers recommendations vary - anything from 1-3 years. Vauxhall used to state at least every year. I'll maybe put up a post on this procedure - if asked. Otherwise a truly excellent demo - well done!:)
 

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Hey all,
Just a quick note for anyone else who is trying to decide to do this or not. I have never done this before and let me tell you, it was very very easy!!! took me about 2hours to do both sides - not bad considering the temperatures and it was dark. I would attempt this again anyday!
cheers for all the info,
stef123
 

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Thanks for this fantastic and clear explanation on how to change the front pads. I have changed pads on my others cars in the past but this is the first time on my laguna so was a bit aprehensive. You have made it so easy to follow so am going staight out to get started!!
Many thanks
Jacko
 

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Discussion Starter #7
Thanks for the positive comments Jacko.:)

Good luck with it and let us know how you get on.

Welcome to the forum by the way.:)
 

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Excellent post, clear and easy to follow. This is what makes this forum so good, people are willing to share information and help each other. There are lots of people out there who are tired of being ripped of by so called mechanics who charge the earth and dont do a good job.

As it says in the post, this is a simple job but if you dont feel confident with spanners dont attempt it....

:d :d :d
 

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hey,
I've done 350 miles since i changed the discs and pads. But now they are starting to squeal slightly, is this normal? I did use brake paste when i put the new pads on aswell...
stef123
 

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Thanks for the great information

Hi

That is very useful information, I think I will print it out to keep for reference if that's OK, as I'm not sure I'll be able to trace it again!

Information about bleeding the brakes would also be great, I have a haynes manual, but sometimes they are not as clear as they could be, and the addition of good photos here is indispensible.
 

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A nice clear explination of it and i can confirm that this is the same for laguna mark 1 both phase with the 2.0l engine and a clio mark 2 1.6 and also a scenic mark 1 p2 as they are the same caliper on all. A good tip is that if you have or can get a bike pedal spaner then its a nice slim 17mm one.
 

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Mine were changed at 70 but its developed a judder on braking. May try new front tyres before the change as I need to change 2 tyres...

:confused:
 

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Changed the front pads on my son's Laguna a few years ago. The discs were held on with Allen Screws which had been rounded. I used a Dremmell type tool fitted with a thin grinding wheel to cut a slot in the head of the screws and used a flat screwdriver to get them out. I always use a "G" cramp to compress the piston and use Copperslip on the ends and back of each new pad to prevent seizing up.
 

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Nice guide, but I have a couple of questions.
Why can't I use copper grease on the back of the pads, when other guides recommend it?
I tried to change the discs but had problems taking the screws out, rusted solid! I have had to leave them until I get an impact driver to have another go. Any advice on how to remove badly corroded bolts/screws would be gladly received.
I also couldn't remove the caliper guides due to the bolt heads being corroded, and I dread having to replace the trackrod ends.
 

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Now I'm confused - why then does the guide say you shouldn't use copper grease?

Cheers!

:d

ps could penetrating oil help on the seized screws, or else get a set of those bits that reverse them out?
 

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Had a look at mine and the front n/s has definitely been changed with copper grease and seems fine - so as far as I'm concerned its ok :d
 

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The brake component manufacturers don't recommend copper grease simply on the grounds that it attacks the rubber caliper seals. Copper grease is primarily an ant-seize compound and has quite low lubrication qualities. Anti-seize compound can withstand high temperatures but it was never really designed for use on brakes. Most brake component sellers can supply a high melting point grease which should only be applied to the edges of the brake pad. You wouldn't want it melt and run onto the discs now would you:)
 
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