[Closed] Changing disc pads on a car,just as easy as a bike right?

In general, yeah.
Bit more awkward - jacking up car, undoing corroded bolts, might have to manually pull the pistons on (sometimes can be done with a big allen key or might need a special tool - not expensive).
Best to put copper grease on the back of the pads too.

back may require you to wind in the piston due to the handbrake. Front just need carefully pushing back in (leave old pad in place and use a clamp).

Some designs don't even need the caliper removing, just retaining pins like a bike. Most front ones do so you will either need a decent socket bar or something long (trolley jack handle) over an allen key depending on the design.

Check the sliders while you are at it. Lube them with proper brake grease and use the same on the pads (buy a tube when you get the pads instead of copper grease).

I'm planning on having a bash at it this week for the first time, I'll report back. From what I can gather from speaking to knowledgeable folk is that it's pretty easy but undoing the bolts can be hard as they're very prone to seizing due to constantly being covered in road crap. Also, you might need some odd sized tools and bits.

Do a google search and find out the size sockets / spanners you'll need. C-clamp is very handy. Blow torch might come in handy, hammer too. Rear brakes can be a bitch depending on the hand brake.

Apparently you'll need to change your discs too (I read that on here so it must be true)

If you know what you are doing, have the correct tools (including a decent jack), all the bolts/fixtures come off easily and you have somewhere inside (or it's a lovely day) - it's a piece of pi55.

Or...

If you DIY don't trust the jack - always slide the wheel that is off under the sill.

If you DIY don't trust the jack - always slide the wheel that is off under the sill.

Or put it on axle stands.

Jack, axle stands and the wheel!!

Don't take chances when you have a couple of tonnes of car above your body.

Oh, and what car is it?

peteimpreza - Member

Jack, axle stands and the wheel!!

Don't take chances when you have a couple of tonnes of car above your body.

It shouldn't really be necessary to get under the car. Turn the wheel away to get better access to the caliper. But of course, safety first.

Depending on the car some ECU's really dont like the pads being changed without being told first. A friend managed a kwikfit and the aprentice did this to a Passat, cost £1600 to have it towed to VW specialist and get it sorted!

Generally what's been said. It's always best to loosen the wheel nuts when the car is still on the ground & do the final tighten when it's back on the ground too.

You don't need to change the discs (don't believe all you read) unless the pads have worn down to metal & the discs are scored up. Or unless they are so badly worn they are too thin - they do have a minimum thickness which will be in the manual. It's always good to look at the braking area to ensure the pads are making full contact. You might also have to lever the calliper off past the discs if they are worn as the wear leaves a lip on the outside of the disc.

Also - as has been said - a G clamp is useful to push the Pistons back to enable the new discs to be fitted - but do keep an eye on the master cylinder as it will fill up with the displaced fluid & some may need to be drawn off.

I actually did cars before bikes - cos bikes just didn't have hydraulic brakes - in the day..........

PS - re modern cars & ECUs - as you are disturbing the wiring (as fronts have wear sensors) & can throw up fault codes it's best to disconnect the battery (ensuring you have your radio code) and re-connect it when all is done.

On re-reading - use a G clamp to push the Pistons back to enable new PADS to be fitted.......

You don't need to change the discs

I would say you probably need to change the discs if they are corroded on the surface or worn concave.

In my experience, this happens every time! Fortunatley discs aren't expensive and are even easier to change than the pads. However it does mean moving the caliper cage which is a bit more of a faff.

Also - don't assume that a few mm of pad material is fine, like it is on bikes. Car pads are usually 20mm thick to begin with, and a few mm left is severely worn and may er.. detatch from the pad backing.. happened to "a friend".

As above, however use a hose clamp so prevent old fluid/crap being pushed back into the ABS pump, and drain any excess off the bleed nipple.

Apparently you'll need to change your discs too (I read that on here so it must be true)

Other way around, replace pads if doing discs otherwise change discs as necessary.

Another vote for thermal grease over copperslip.

Not sure about clamping, the fluid in there is essentially the same as the stuff in the reservoir, never heard of that one...

If the car has an electronic handbrake, the rear pad change may be have its complications.

As jimjam says, check the bolt/allen key size. I remember finding it was an odd (or at least not one I had) after I had the wheels off. Had to put everything back to drive to Halfords to get one that fitted.

Halfords do a cheap brake piston winder which works a few times before breaking.

Hope the previous mechanic didn't put locating screws in and wound them up tight - had to drill a few of those out.

I've never had to clamp a hose but I do take the lid off the fluid reservoir when pushing pistons back in and check the level again after the job.

I've never worked on a car made after 1999 so YMMV if it is!

Depending on your car, if you are taking the discs off they might be held in place with a funny sized hex key. I think on a lot of VAG cars it is 7mm.

AlSo the pistons on some rear calipers rotate as they come out of the caliper so you can't just push them back in. A caliper wind back kit will make it loads easier and they don't cost a lot.

[i] Fortunatley discs aren't expensive and are even easier to change than the pads.[/i]

except when the disc and hub are a single assembly...

If taking the discs off then impact driver (the type you hot with a hammer) to undo the screws if they are tight. When you refit apply plenty of grease (I do use copper slip for those).

get a wire brush and clean up all the calipers. But be careful around any piston seals (I use a nylon brush around there). Also get yourself some brake cleaner.

You may also need thread lock for the caliper bolts (the blue prit-stick style loctite one from halfords is very good).

Fortunatley discs aren't expensive and are even easier to change than the pads.

depends on the car, some are. And as for easy it depends on if the person who fitted them put enough anti-seize on the disc screws.

Don't forget brake fluid needs changing every couple of years too.

What car OP?

Our Yaris my eldest changed discs and pads at 10 years old under supervision - jack, stands, wheel off, one bolt, rotate caliper, new discs and pads on, rotate caliper, bolt do up, wheel on. Sorted.

VW - seized bolts and three different sized fittings on four bolts of various kinds, including one hidden inside. Wharra faff.

Ive heard of the clamping and bleed nipple thing when pushing pads , saves inverting seals in the m/c or the abs pump or what ever on modern faff cars.

Never worked on modern technology cars though ( and with that i mean anything with abs) Purposfully avoid the modern junk , even mechanics often struggle with repairs on modern cars these days.

I have modern junk, G clamp works every time. You would have to be properly ham fisted to do it I reckon. Just open the reservoir and take it gently.

I saw a warning for my car about inverting brake seals but only after I'd done the pads a couple of times with a gclamp 😳 Is it actually a genuine thing? Seems to be a lot of "a mate" stories about it.

Is it actually a genuine thing?

Yes. Early VX Astras had a reputation for this - happened to me once.

Best practise is always to clamp the hose, open the bleed nipple and then push the pads/piston back into the calliper.
Tighten the nipple, remove clamp, fit pads and top up brake fluid.

Hth
Marko

Ive got Pagid discs, just waiting for Brembo pads (cheap- opi oils on ebay).

Because freak accidents can happen to any DIY'er always slide the wheel underneath IMO.

Cheers Marko, I'll do it right in future then 😀

It is a vauxhall Astra 1.4 2009. It got new discs in August as Kwikfit refuse to change pads onto discs with the slightest wear,I am buggered if I am going near them again. It has about as many electronic aids as a Sopworth Camel,and is slightly lower in spec as well.

why have you gone through pads already is the question id be asking.

are you doing mega miles ?

anyway - front or back pads ?

there are videos on youtube of the process , front is easy , rear needs a windback tool - ****ing about is just that - its ****ing about. 100% easier/safer and less chance of ****ing it with a windback tool.

Obviously check what tools you need first ! Dunno about Vauxhall but BMW & VW brakes I've done have both needed 7mm Allen keys which don't always come in the basic tool kits. I've also found a breaker bar invaluable (like [url= http://www.amazon.co.uk/Draper-Expert-33596-600mm-Handle/dp/B0001K9SRU ]THIS[/url]) as the joint by the head means you can use it positions that a normal ratchet won't reach. The BFO bolts holding the caliper bracket to the hub for example.

Otherwise it should be a very simple job. Clean everything before you put it back together. As well as the back of the pads, a little Copaslip where the pads move in the caliper bracket probably won't go amiss. Internet opinion always seems to be divided as to whether you should grease the slide pins. I used to but now I don't. I have never noticed any difference either way <shrug>.

Specific VAG thing - the story above of a Passat throwing its toys. Impossible to comment on that one without knowing the full details but on our B6 Passat with the electronic handbrake you CAN change the rear pads yourself and it DOES NOT need a dealer to reset the ECU. I've changed both rear calipers due to the handbrake mech failing (thanks VW...) and all you need to do is wind the piston in until it bites then back off about 1½ turns. The car will then fine-tune itself.

I am doing a lot of miles Terry,been up the hills a lot finishing the Munros,then sick parent in Inverness most weekends.Plus was driving from Fettercairn to Carnoustie every day for work till fairly recently

BMW & VW brakes I've done have both needed 7mm Allen keys which don't always come in the basic tool kits.

Cue lots of angry swearing at VW and 'who the f specs a 7mm allen bolt' rants.

"a little Copaslip where the pads move in the caliper bracket probably won't go amiss."

Copaslip goes gummy then hard with the addition of heat - in many cases it causes more issues than it solves.

Heat resistant ceramic grease is the way forward.

If i knew i was gonna be about at the weekend id suggest a drive over the cairn and we can do it on the drive at mine, im almost certain ill have any tool required for the job - ive done enough folk on heres pads and other things on their various bangernomics wagons. How ever right now im down to travel to oz on saturday. Will let you know if that changes.

you mean you dont have a 7mm allen key in your basic tool kit in the shed 😉

i first encountered them on a BMW motorbike fork i was servicing for a mate.... i guess its a german thing.

Lots of them use them. Dunno why but maybe it's to stop people using a ratchet and overtightening?

Tool is cheap enough: http://www.eurocarparts.com/ecp/p/tools/car-service-tools/brake-service-tools/brake-system-tools/?SEAAK6572&0&t5_390

Doesn't stop you at all - I went to halfords, the only 7mm allen key they had was a 3/8" drive bit 🙂

i guess its a german thing.

Along with twelve pointed star bits aka 'foursquare' bits. Had to buy a set off ebay, glad I did as they are all over my car.

like an inverse bihex ?

if you got them holding on your calipers duckman then im stuffed - dont have em.

I have to say some of the advise given on here is shocking .

Brakes save your life and the lives of others around you , if you are not 100% sure about what you are doing please leave it to an expert .

Make sure you measure the discs before ordering including (hub / internal diameter). We found that the discs and hubs on our Jazz were not consistent with the year it was built! I ordered online using the old select your model / input your reg no., they turned up with the pads and didn't fit. The pads are however fine!. £16 return postage on a £25 pair of discs. I'll be keeping them I think!

and the offset.

this is why the dealers ask for the vin when you order parts through them.

honkiebikedude - Member

I have to say some of the advise given on here is shocking .

If you are going to be critical about the advice people are giving, then at least spell it correctly.

Yup

Claiper piston tool might be necessary, a G clamp won't always do it (not overly expensive)

Might need 7mm allen key (not usually in sets)

Check the new pads carefully, it's not unusual for a dozy supplier to give you the wrong parts.

Observe any clip, spring and wear sensor wiring arrangements and make sure they are the same with the new pads.

If your disc has a big stepped edge where it has worn away, it should be replaced as well, again an easy job (remove the retention screw) can require measured brute force and/or heat to separate from the hub.

Temporarily take reservoir cap off while pushing pistons back

Use copper grease (or supplied compound) on the backplate of the new pads not the braking surface obviously!

Check reservoir level and top up if need with the correct fluid when finished.

Advice given here has been good thus far, ignore the whiny doom merchant. If your reasonably mechanically savvy, got the tools, oh and your not one of those who rounds and strips every thread you come across in a temper, it's not difficult, it's not as easy as a bike though! Exhausts and servicing the same with the exception of mid engined sports cars, flat cylinders which are trickier for a novice.

Get it done old bean.

honkiebikedude - Member

I have to say some of the advise given on here is shocking .

If you have an issue with any advise that you think is so shocking, you should tell people what, and why tbh.