Q’s on Brake Pad Change - fluid type, paste application, cleaning

[xvvvz]

If it doesn’t rain this weekend, I am going to try changing the front brake pads on the C230K this weekend for the first time and would appreciate some advice for a newbie. I bought a set of PBR/Axxis Deluxe Plus pads, sensors, and MB paste. With only 32.5k on the car, the rotors seem to be within specification when I measured them a few months ago so I don’t plan to change them.

I have searched many helpful threads but still have some questions. If someone could please share advice on the following, I would really appreciate it:

Brake Fluid Type – I am going to flush the brake fluid too. I have seen recommendations to use both DOT4 and DOT4+. DOT4+ is almost impossible to find unless you go to the dealer and pay out the ying-yang. Is DOT4 ok? I really don’t have a need for the fancy $$ racing fluid and would rather stick with the semi clear coloring to make it easier to judge over time for cleanlieness. If I can find something quality like ATE DOT4, will that be OK? I guess I could go with DOT5.1 (the non synthetic one) as an alternate. Searches here on DOT4+ didn’t turn up much.

BrakeKleen – is it advisable, and more importantly safe for the w202 components, to use this to pre-clean things before starting to work? I don’t want to damage things. What about using a wire brush to clean things up and knock off the rust? Not worth risking damage?

Brake Pad Paste - I have searched the archives and found a decent thread but am still not sure exactly where to apply the paste and how much. The MB WIS just shows to apply it in the piston-side pad around the perimeter of the piston contact area. Other posts indicate to apply it to both pads. Here are the backs of the inside and outside pads plus a picture of my caliper I took last fall (but unfortunately didn’t study close enough to really familiarize myself with the setup while the wheel was off). Feel free to edit them to show a visualization:

http://www.betterscanning.com/p/outerpad.jpg

http://www.betterscanning.com/p/innerpad.jpg

http://www.betterscanning.com/p/calipercolored.jpg


Would that be a shim pad separate from the brake pad’s backing plate showing back behind the silver (shaded pink here) part of the caliper or is that the actual backing plate of the pads?

If there is a separate shim pad there, do I just completely cover the back of the pads backing plate with paste and be done with it?

If there isn’t a separate shim pad, do I just cover the areas of the pads backing plate shaded I pink where it would come in contact caliper?

What about the metal clips? Do they need paste applied all over the metal?

How thick of a layer of past should be applied?

Thanks!

[Nelson Lago]

http://http://i179.photobucket.com/albums/w293/CLK_011/innerpad2.jpg

[Nelson Lago]

http://i179.photobucket.com/albums/w293/CLK_011/innerpad2.jpg[/IMG]

Well i would add a thin layer of past to the back of the pad.

As far as brake fluid dot 4 should do it and you cant use dot 5.

[xvvvz]

Holy $#@@$! The parts box just arrived from autohausaz.com. I can't believe this is all the paste they give you per packet (notice the one stood up on its side to the right) and that you are only supposed to need one packet per caliper (inside and outside pad). That is supposed to cover all that area you showed on two pads? Wow. BTW, the stealership wants $4.00 for each one of these!

http://www.betterscanning.com/p/padpaste.jpg

[Proven Guilty]

yeah, apply a thin coat to the back of the entire pad. some of it will never touch a surface to cause the vibration, but some will rub off on your fingers when you're putting it together anyway, so excess never hurts in this department.

just make sure you don't let ANY of the paste touch the brake pad surface itself, or get on the surface area of the rotor.

2-3 packets should so it, it's a synthetic lubricant so it spreads really well and sticks on there. if you run out, you can always buy more paste at autozone, kragen or parts store of your choice. it's only like $1.50 per packet there.

the caliper dissambly is pretty straight forward. the pic you've highlighted in pink shows the center part as the caliper, and the outside part as the mounting bracket. they slide apart when you pull the caliper outward to remove the pads. the metal bracket if i recall goes into the inside where the outside has those retaining spring-loaded pins also viewable in the pic you posted w/ the pink.

the only other thing you might not be aware of, you'll need a breaker rachet. that's not the technical term for the tool, but i don't recall what its actually called. allows you to strike the handle with a hammer to give it an 1/8th of a turn counter clockwise. this is going to be for the bolt that holds the rotor to the hub. some cars are allen bolt, some are phyllips style driver bolt, but if its allen key you can probably get away without the tool.

just pop a wheel off and look at the rotor before you get into dissambly so you can drive to the parts store and pick a tool up if yours had the philips style bolt.

as far as brake cleaner, just keep it off the rubber as much as possible, as it can severely dry them out leading to cracks and failure. i scrubbed my calipers down with wire brushes, and repainted them with ceramic brush-on paint that can be picked up for $30 or less at autozone. they have black, silver, red, yellow, and blue - silver looks great on the W202s for a clean OEM look since the brakes are so small. red looked great on the W208 since it has much larger brakes.

[Proven Guilty]

forgot to mention, these were the exact same pads i used to have. you'll really enjoy the low dust output. id say its almost 85% reduction in pad dust vs OEM.

I've got a set of stainless steel braided brake lines which are teflon coated and includes ATE typ200 brake fluid i was going to use on my 99 C230K if you're interested and haven't selected your fluid yet.

[AirPost]

Originally posted by Proven Guilty
forgot to mention, these were the exact same pads i used to have. you'll really enjoy the low dust output. id say its almost 85% reduction in pad dust vs OEM.

I've got a set of stainless steel braided brake lines which are teflon coated and includes ATE typ200 brake fluid i was going to use on my 99 C230K if you're interested and haven't selected your fluid yet.

You haven't sold your brake items yet? PM me for the special, discounted price with shipping. :D

[xvvvz]

Thanks for the information!

[OzC36]

From the photo, your disks (rotor) look to be worn close to limit. Check they are still within tolerance.

[Logic]

if i recall when i had my brakes done mercedes soaks the pads in some anti squek solution by BK . isn't it wise to resurface the disc also? by the way since you are doing your brakes repaint those calipers. doesn't look like you prepped those right since you dont have equal paint on them . to make them look really cool take the retention spring off before you paint them and wire brush the spring ( the one you put on the drill works best) and they will look like a brass color , makes them look better then painting them.

[xvvvz]

>>From the photo, your disks (rotor) look to be worn close to limit. Check they are still within tolerance.<<

Good advice. Definitely something I checked. On the 202.024, the MB WIS says when changing your pads check the rotors and if they are less than 23 mm you should change them with the pads (rotors start at 25 mm and are not supposed to be used past 22 mm according to the MB WIS). Mine were over 23 mm, so I am going to see how I get along.

>>isn't it wise to resurface the disc also?<<

You are never supposed to resurface rotors on MB according to the service information I have read. You are supposed to measure and then totally replace if not in specification.

>>doesn't look like you prepped those right since you dont have equal paint on them<<

They have never been painted. That is just 8 years and 33k miles of dirt/dust.

[Logic]

so the purple on there is? i see many mercedes that have been resurfaced, i m not sure where they had them done but when i got mine and replaced the fronts with crossed drill i noticed the rotors have been turned since the edge was thicker then the middle of it hmmmmm.

[anf6789]

the purple was on there to show/highlight a specific areal xvvz wanted shown, in otherwords it was *photoshopped*.