Replacing 2003 ML270CDi pads - advice needed

[Bobby Dazzler]

I have a 2003 53 ML270CDi. The brake wear indicator is glowing on the dash when braking sometimes, so it's time to take action. Don't fancy the quote from the MB dealer, so I plan to have a go myself.

Pricing up the pads from various sources, and my local motor factor said that they have two different shaped pads listed for my car, and both state suitable for a 303mm disk. Forgive the awful descriptions that follow...

(1) Square-ish shape secured by two pins.

(2) W-shape-ish secured by a spring clip.

Any idea which is likely to be correct?

Also anyone know if you can re-use the wear sensor in the replacement pad, or whether you have to buy new sensors?

Finally any tips gratefully received:
>> links to how-to guides;
>> suggestions for pads to avoid notorious ML squeal; and
>> suggestions on suppliers in UK.

Many thanks in anticipation!!

 

[oigle]

Haven't had to do that yet. What mileage have you done? There is usually quite a bit of meat left on the pads after the light begins to come on.

Re type, it is quite a simple task to take a pad out and have a look - probably 15 minutes work. Be good practice for when you do it for real!!!!!

 

[Bobby Dazzler]

Could probably do with the practice!!

The car has done 29,800 ish. Owned the car since 23,000 and looking back through invoices, it appears that the pads/discs have not been changed. From what I've seen on the web and what my MB dealer says, this is little short of a miracle!! Although as an ex-MB car it's unlikely to have been subject to a DIY replacement.

I've been paranoid that they'd need doing soon, having bought at 23,000 and asked the dealer to take a look a few weeks ago when in for warranty work (another story!!) - they advised 70-80% worn. Miraculously the light started appearing just TWO days later ...conspiracy theories welcomed!! Then did 1,000 miles then in 6 days on a tour of Scotland, so thinking I don't have much grace left!!

Been a while since changed discs/pads, and last time was on a car worth 10% of what the ML is worth, and nowhere near as reliant on technology (it even had a carb - remember them??!! lol). So just need to pluck up the courage. Be brave, be brave.

 

[oigle]

I think you guys must give brakes a harder time in the UK than we do in Oz. Perhaps the weather conditions are worse (wet and salty) and I know you drive faster - our thought police keep us under 100kph on most roads with 110kph being for our best roads - great!!!!!!

My ML270 has done 35000km/21000miles, mainly towing a 1600kg caravan and the brakes are still OK. I must admit to being deliberately easy on brakes where I can.

What warranty issues have you had? Mine have been throttle cable sticking (3 times), engine mounts replacement (engine became buzzy)and a gear lever knob replacement(knob leather bubbled). I eventually had a throttle cable made up with a different inner cable (used the original outer) - MB dealer fitted it for me free - and that fixed that issue.

There has been a recent discussion on the forum re where later RHD ML's are made. Mine (2003 model) is from Alabama, USA - where did yours get made?

 

[Bobby Dazzler]

None of my warranty claims seem to match. From what I can remember there have so far been:

2x Catalytic Converters (expensive apparently over £3,000 including labour ...GULP!!);

ESP/BAS Wiring replacement;

Wear on child seat, replaced twice in 6 months!! (fabric only - seat fine);

Grey foil between front and rear side windows peeling - going in next week;

Fuel gauge erratic reading - going in next week.

May have been one or two other things, but can't recall.

When I bought it, I asked the dealer to check from the chassis number whether it was Austrian or American built, and they said Austrian. Who knows though (??!!), as the dealer also booked me in to have the foil and gauge replaced (mentioned above) with 4 weeks notice, but called me 8 hours after I dropped the car off to say that they hadn't ordered the parts!!

 

[paulcallender]

New brake pads should come with the little electrical connector to the wear indicator. If they don't, then try and obtain some (they are not expensive) or if you cannot, then if undamaged there is no harm in reusing the old ones. They are not exactly safety-critical!!

 

[Bobby Dazzler]

New brake pads should come with the little electrical connector to the wear indicator. If they don't, then try and obtain some (they are not expensive) or if you cannot, then if undamaged there is no harm in reusing the old ones. They are not exactly safety-critical!!

Thanks Paul. You must have read my mind - was just wondering whether you could re-use the sensors!!

 

[Bobby Dazzler]

Found images of the two types of pads here: http://www.speedways.co.uk/apec/list/mercedes-benz/landcruiser.htm

It suggests that pre-2000 the calipers were Kelsey and designed for use with 303mm discs, and are the w-shape pads I described above.

It suggests that post-2000 the calipers are Brembo and designed for use with 345mm discs, and are the square pads I described above.

So from that that I'm beginning to think it's the square ones for my 2003 ML270CDi - what do you think?

Do 2003MY ML270CDi have 345mm discs?

Any help much appreciated!!

 

[Bobby Dazzler]

Following my previous pots, my car does have the 345mm front discs and Brembo four-pot calipers.

Had the wheel off today to look at what's involved. Doesn't look too bad, although...

It seems that my car has four-pot Brembo calipers - I'm a bit concerned about how I push back the pistons safely, without one popping out or causing any damage. Anyone got any tips on how best to do it?

Where do I put the anti-squeal paste:
>> between the the metal shim/plate on the back of the pad and the piston/caliper??
>> between the pad and the metal shim/plate??
>> both places??

All help gratefully received.

 

[The Editor]

Also..... be very careful not to 'wake up' the braking system from it's slumber when you are changing the pads !! This can be done by simply opening the drivers door (remember that familiar sound of the braking system pressurising and self testing after you have unlocked your car and opened the door.

If your fingers are anywhere near the calipers when that happens you will get 180 psi pressure squishing your pinkies !!! :? .. Carefully pick them up from your driveway, put them in a plastic bag and get a friend to drive you and your fingers down to the nearest A & E !!... Just a warning.... Don't touch the remote and don't let anybody open any doors ...

Good luck


Mark

 

[Bobby Dazzler]

If your fingers are anywhere near the calipers when that happens you will get 180 psi pressure squishing your pinkies !!!

Cheers Mark, much appreciated. Hadn't realised this, so I'm very glad you mentioned it!!

 

[davidsl500]

Also..... be very careful not to 'wake up' the braking system from it's slumber when you are changing the pads !! This can be done by simply opening the drivers door (remember that familiar sound of the braking system pressurising and self testing after you have unlocked your car and opened the door.

If your fingers are anywhere near the calipers when that happens you will get 180 psi pressure squishing your pinkies !!! :? .. Carefully pick them up from your driveway, put them in a plastic bag and get a friend to drive you and your fingers down to the nearest A & E !!... Just a warning.... Don't touch the remote and don't let anybody open any doors ...

Good luck


Mark

best put a bowl under the caliper to catch the fingers as it will be difficult to pick them up .........

Dont forget that as you retract the calipers then the brake fluid level will be rising in the reservoir and may overflow - not a good thing to have corrosive brake fluid leaking over everything..... best extract some out first - with a turkey baster or syringe.

 

[Bobby Dazzler]

Quick note to let you know that pads are now replaced!! Thanks for all the help - very much appreciated!!


For anyone reading this thread in relation to replacing their own pads...


This article really is invaluable - it's very accurate and gives an excellent indication of what's involved - all credit to it's author. Don't be phased by the fact it's for a W124 (E-class?), as the procedure, calipers, and parts appear to be identical to that of the W163 (M-class):
http://www.mercedesshop.com/Wikka/W124BrakePads


This article (extract from MB dealership documentation I believe) is handy, but just too cumbersome to actually be of real use. Best take a look, and then use the W124 link above. That said it is still worth a look though:
http://phdwebsite.powerpulse.cc/Mis...d caliper.pdf


Key learning points:

(*) As pointed out by another owner, make sure that the doors are not opened, closed, locked or unlocked whilst working on the brakes, as apparently this can pressurise the system, and cause damage to fingers if they get in the way. Didn't whitness this myself though.

(0) Been 12 years since I last changed pads and that was on a Vauxhall Nova and am very very reluctant to get my hands dirty!! This really isn't any more difficult. Don't be phased by the electrickery that associated with the brakes. The wear sensors are just push fit at each end!! It really is relatively easy to do, butif in doubt, consult an expert!!

(1) Buy a drift punch as making do with nails and screw drivers takes longer than necessary.

(2) Syphoning (spelling?) excess brake fluid was the trickiest job of all. The draper kit I bought was a pain to use - unless it was me using it incorrectly - which is a very real possibility!! Take care with that paintwork!!

(3) If the wear sensor is in the way when removing/inserting retaining pins on the rear axle, it looks like the bracket that it's mounted on can be removed with a single nut. I managed without removing though.

(4) Getting the front wheels back on was the most frustrating and time consuming job of all - getting it positioned correctly is a pain - and ironically is the most difficult aspect of changing the disks!! If you can do this then you can change the pads!!

Thanks to those that helped, and good luck to those that are reading this with a view to doing it themself!!

 

[tom7035]

Hi.
Re (4) above; "Getting the front wheels back on was the most frustrating and time consuming job of all - getting it positioned correctly is a pain - and ironically is the most difficult aspect of changing the disks!! If you can do this then you can change the pads!!"

My toolkit has a positioning pin which is screwed into the hub to assist fitting the wheel, and taken out once a wheelstud is in position.

 

[Bobby Dazzler]

I looked for lug/pin but couldn't find one. Will mention it to my dealer ...or maybe get my wife to look for it first (I can see past the end of my nose!! - I think I'm just lazy!! )