W211 E320CDI 2007 facelift front brake pads change: do I need to disable pumps/bleed, how to jack the car up

[Stocho]

Hi,

Brake pads warning has been on for months. Inspected brake pads when it first appeared and there was at least 5-6mm left (looked at the outer side only) so assumed faulty sensor. Inspected yesterday still at least 4mm left on the outer side. The inner side looks like almost completely warn out.

It looks like original pads including sensor, bolts, some other staff can be bought from a dealer on Ebay at a good price:

Genuine Mercedes-Benz W211 E-Class FRONT Brake Pads and Sensor A0004207104 NEW | eBay

Suitable for most W211 E-Classes Excluding AMG Line models. © 2021 Sytner Group Limited. Useful Links. Can’t find what you're looking for?.

www.ebay.co.uk

The questions I have:
1. Do I need to disable anything electronically as seen some horror comments on the internet about pumps getting activated even with ignition fully off (i.e. key out)?
2. Do I have to open a bleeder valve to ensure the fluid from the piston does not flow to parts of the system where any debris might cause damage? If so is there a risk of introducing air into the system/how to deal with it?
3. If I could get both wheels off the ground it would make the job very easy but I have just a poor quality jack that came with the car and some old axle stands. So will be doing one side at a time. Can I turn the front wheels to the maximum before jacking (to maximally expose the caliper)? Will it be safe to jack the car with wheels turned to the maximum? Will I be actually able to get the wheel off when it is turned to the maximum?

 

[pmcgsmurf]

The questions I have:
1. Do I need to disable anything electronically as seen some horror comments on the internet about pumps getting activated even with ignition fully off (i.e. key out)?
2. Do I have to open a bleeder valve to ensure the fluid from the piston does not flow to parts of the system where any debris might cause damage? If so is there a risk of introducing air into the system/how to deal with it?
3. If I could get both wheels off the ground it would make the job very easy but I have just a poor quality jack that came with the car and some old axle stands. So will be doing one side at a time. Can I turn the front wheels to the maximum before jacking (to maximally expose the caliper)? Will it be safe to jack the car with wheels turned to the maximum? Will I be actually able to get the wheel off when it is turned to the maximum?

Do yourself a big favour and get a local guy to do this if you can find one, otherwise you would be best going to an Indy.
If in any doubt at all best to stay well clear and leave it to those with experience.

 

[AMGeed]

^ Agree with above. Leave it to an indy or any garage to change them. Shouldn't cost much.
A 2007 W211 shouldn't have SBC, so no pump to worry about.

 

[clk320x]

I thought 2007 cars don’t have SBC?

 

[Stocho]

^ Agree with above. Leave it to an indy or any garage to change them. Shouldn't cost much.

It is not a question of cost, these are very unusual and dangerous times. My mechanic is something like 60 miles away from me.

Any garage? Yeah, exactly what police will tell me if they stop me 50 miles from my home!

Well, the first video that came up on youtube is:

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The guy, who is a professional mechanic, just let that huge caliper hang on the brake pipes! Also answering my 2 question he did not bleed the excess fluid - he pushed it back, which I know on some cars can cause thousands in damage.

Stopped using any garage when on my W210 (now long since gone, on which I changed front and rear disks and pads myself):
1. F1 Autocentres put 1 litre of oil over the maximum. Refused to remove h excess saying "its good for the car and i will but with time"
2. Halfords autocentres when changing oil did not screw the two bottom shields to the frame of the car but used straps to strap the two bottoms shields/covers to each other. Looked ok to them when the car was stationery. On motorway those shields were hitting the tarmac - extremely dangerous. Here is a post about this from 8 years ago: Halfords Autocentres messed up undertrays - where to get new ones cheap? | Bodywork

 

[Petrol Pete]

With your above post you have half answered your own question. The money you are going to save by doing it yourself should be spent on a decent trolley jack and good quality axle stands.

There is a rubber pad beneath the engine (RTM) jack it up from there and crack on.

PS there is a good chance the inner face of your discs will be showing more wear then the outer face, check that first.

 

[AMGeed]

It is not a question of cost, these are very unusual and dangerous times. My mechanic is something like 60 miles away from me.

Any garage? Yeah, exactly what police will tell me if they stop me 50 miles from my home!

Well, the first video that came up on youtube is:

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The guy, who is a professional mechanic, just let that huge caliper hang on the brake pipes! Also answering my 2 question he did not bleed the excess fluid - he pushed it back, which I know on some cars can cause thousands in damage.

Perhaps I shoud have qualified my earlier reply by saying "any trustworthy and competent garage", hence using an Mercedes indy.
When my indy changed the discs and pads on my previous W211 (with SBC), he removed some brake fluid from the reservoir and forced the pistons in and the fluid back through the brake pipes with no harm done. How can it, its a sealed system that dirt can't enter into.
I'm sure he wouldn't have done that if it was going to cause "thousands in damage"

Changing front pads is a simple enough procedure and you asking the questions you did in Post 1 led me to believe you aren't really competent enough to do the job yourself or have never done it before. Again, why I suggested using an indy or other garage.
But I'll answer those questions anyway now I'm posting.
Q1....No, nothing to disable. You have a facelift W211 with no SBC pump as I mentioned in my earlier post.
Q2 ...No you don't have to open the bleed valves. You can if you want, and then pump the pedal afterwards with a bleed kit to expel any air in the system. Remember to take the fluid reservoir cap off , keep topping up the fluid and not let the level drop when you are pushing fluid out.
Q3....Yes you can turn the wheels on full lock to get better access to the caliper before jacking the car up. When the wheel is on the ground, crack all the wheel bolts so they will undo easily when the car is raised.
Put a chock behind and in front of the rear wheel to stop it moving and put the wheel you take off under the sill to protect you should the jack become unstable. I'd buy a decent trolley jack and axel stands first. Make sure it goes low enough to go under the jacking point. Not all jacks will do that.

 

[pmcgsmurf]

3. If I could get both wheels off the ground it would make the job very easy but I have just a poor quality jack that came with the car and some old axle stands. So will be doing one side at a time. Can I turn the front wheels to the maximum before jacking (to maximally expose the caliper)? Will it be safe to jack the car with wheels turned to the maximum? Will I be actually able to get the wheel off when it is turned to the maximum?

The questions you ask here give me the impression you don't have the tools or the confidence to do the job.

There are still mobile mechanics working, certainly in my area, it's an hour job, maybe a little more.

 

[DSM10000]

The fact that you have uneven wear on the pads is something that needs investigating as you may have a seized caliper.

 

[BlackC55]

This may help.

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Also, are your discs ok?

 

[BlackC55]

The fact that you have uneven wear on the pads is something that needs investigating as you may have a seized caliper.

That is pretty common nowadays, even without a seized calliper.

 

[DSM10000]

That is pretty common nowadays, even without a seized calliper.

That is interesting, why would that be?

Still sounds like it needs checking poperly by someone with relevant knowledge and experience though.

 

[BlackC55]

That is interesting, why would that be?

Still sounds like it needs checking poperly by someone with relevant knowledge and experience though.

Cheapo pads, no anti-seize grease do to pressure washing.....

 

[Gollom]

It is not a question of cost, these are very unusual and dangerous times. My mechanic is something like 60 miles away from me.

Any garage? Yeah, exactly what police will tell me if they stop me 50 miles from my home!



Where are you. Someone may be able to suggest a trusted Indy closer than your normal mechanic?

 

[Stocho]

This may help.

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Also, are your discs ok?

Thanks for the video, and for the replies. If I go ahead with doing it, will try to get that penetrating fluid as should definitely make the job easier (though only available from one site with 5 day dispatch - not in time for the next weekend). Can it also be used to help with removal of old discs by spraying into the hole where the hex/T30 bolt that holds the disc sits?

With regard to discs they are quite warn out but other than wear no obvious problems. With regard to wear, I could file down the lips to measure or try to get a special measuring tool to measure it. What is the minimum safe disc thickness for this car?

 

[BlackC55]

The disc minimum measurement is stamped on the hub of the disc.

No need for the spray on the disc retaining screw.

 

[Petrol Pete]

OP , without being rude on reading your posts I am not sure you are ready to do this job. It is a simple job when everything goes right but you are asking about freeing up the countersunk bolt that holds the disc on.

This can go one of two ways.

Either the person who was here before you did everything properly and the bolt will simply unscrew with no fuss.

Or the person before you half damaged the screw getting it out and then completely frucked it up mashing it back in because he forgot to order a new one (the are not always supplied with replacement discs) . Penetrating oil will not 100% help because it can not reach the threads past the countersink . At this point you get out your micro-flame MAPP gas torch and find (if you are lucky) that you can get to the threaded area from behind the disc - at this point you have hit the flat face of the screw with a hammer and brass punch - more than a few times - to help shock the threads.


When this fails you get your Dremel out (other fast wizzy cutting tools are available) and you cut a screwdriver slot in the bolt and combined with all the previous heat and violence you manage to remove the screw with your impact driver .

You then go to the other side expecting to do it all again but on this side the bolt just pops out no problem .

Ask me how I know . and good luck.

 

[Stocho]

Also, are your discs ok?

Today tried to measure the disc and at the same time tried to remove that countersunk screw. Without proper tools but with filing down lips on both sides I measured the disc about 25mm. This means that it is a good idea to replace it. I could not see anything on the disc or hub and they are far from pristine condition! However quick search on the internet revealed that new discs are 28mm and replacement is recommended at 25.4mm.

Even if due to error in the measurement it is 26mm I would still rather replace it as remember regretting not doing it earlier on my W210 which was scrapped with 4 essentially new brake discs!

 

[Stocho]

OP , without being rude on reading your posts I am not sure you are ready to do this job. It is a simple job when everything goes right but you are asking about freeing up the countersunk bolt that holds the disc on.

This can go one of two ways.

Either the person who was here before you did everything properly and the bolt will simply unscrew with no fuss.

Or the person before you half damaged the screw getting it out and then completely frucked it up mashing it back in because he forgot to order a new one (the are not always supplied with replacement discs) . Penetrating oil will not 100% help because it can not reach the threads past the countersink . At this point you get out your micro-flame MAPP gas torch and find (if you are lucky) that you can get to the threaded area from behind the disc - at this point you have hit the flat face of the screw with a hammer and brass punch - more than a few times - to help shock the threads.


When this fails you get your Dremel out (other fast wizzy cutting tools are available) and you cut a screwdriver slot in the bolt and combined with all the previous heat and violence you manage to remove the screw with your impact driver .

You then go to the other side expecting to do it all again but on this side the bolt just pops out no problem .

Ask me how I know . and good luck.

Today without any penetrating fluid I quite easily managed to undo (and redo) the two bolts that are in the sliding pins which allow caliper to move. Hence I believe changing the pads will be a very easy job.

Disc is a completely different story. Looks horrible. I tried to undo that countersunk screw with some imperial hex key which seemed a good fit and after trying with quite a force it is no longer a good fit... T30 bit does not go in, T25 is too small, 4.5mm hex too big, 4mm hex too small. So removing that countersunk screw will be quite a challenge. I was hoping that perhaps that "magic" torsion spray will help - but the above suggests it will not.

But suppose I do get that screw out (I suppose it could be drilled out - at least centering the drill bit will not be a problem with this one) isn't the next step, actually removing the brake disc even more difficult? I was thinking of trying that torsion spray in the wheel bolts holes in the hope it will go from there between the brake disk and the hub.... Do I have to brace myself for sledgehammering it out like I had to do on W210?

With regard to those countersunk screws I could adopt the following course of action:
1. Wait for torsion spray to arrive
2. Try to get them off. If I do as long as I do not dislodge brake discs I could just put wheels back on and it should be ok to drive without those screws.
3. If success buy brake discs, if not - do not buy brake discs.

 

[Petrol Pete]

Stocho, as I described in my post , heat is your friend , but its best to use a torch with a very fine flame that you can control the strength of and just as importantly the direction you aim it at.

On my car I was able to get to the back of the screw as it poked out the back of the hub and heat it up there. I also sprayed it there but I uses Loctite 'Freeze' release spray..usually very effective.

Hitting the flat face of the screw with a flat punch and hammer is and old trusted method to help 'shock' the bolt free.

I am not sure with your car but most are held in place with just one small screw (the road wheel technically holds the disc on) Unless seized on a alignment lip the disc should just pop off.

If you do replace the discs yourself do not forget to 'polish up' the disc mating surface of the hub before installing the new discs.