Brake Pads? - PeachParts Mercedes-Benz Forum

#1 06-03-2002, 09:36 AM

How hard is it to change your own pads on a 300E? I read the DIY articale on the E420. Dosn't seem too hard and i just hate spending $150 on 2 pads at the shop.

I was talking to my old Shop Teacher and he said you need a feeler gauge to check to correct space, but that doesn't seem to be in the DIY E420 section. Maybe hes just used to his old American/Japaneese Cars

.

This is a skill that I feel I need to know, becasue it seems so easy and i want to learn how to do it.

Need any special tools? Is the only new thing you need are pads? that is if your discs are all scratched up.

Thanks in Advance

Michael · #2 06-03-2002, 09:48 AM

If you plan to just change the pads, and the rotors are fine, then this job is cake. First, suction some fluid out of the Master Cylinder so when you compress the caliper pistons you don't overflow the reservoir. Jack the car, & remove a front wheel. Once the wheel's off, all you'll need to do is to un-do one of the bolts at the rear of the caliper that holds the caliper to the carrier (you'll need to hold the "pin" that the bolt goes into-it is the part that the small rubber bellows attaches to). Once one is undone, simply pivot the caliper away from the rotor-compress the piston into its bore with a large C clamp, then install the new pads (make sure you have clipped the wear sensor to one of the pads). Pivot the caliper back into place, re-install the bolt you removed (either replace with a new bolt or apply strong thread lock compound), and connect the wear sensor. Repeat for opposite side.

When you're done, pump the brakes in place (never exceed 75% of the range of motion of the pedal-do NOT push all the way to the floor) until the pedal is firm. Fire it up, and take it for a nice easy ride & bed the pads properly.

Good luck!

#3 06-03-2002, 10:01 AM

Ohhhh it sounds soo easy, but i have no trust in myself!!! But i will try it soon, first comes the new radiator, then the new pads.

Thanks a lot Michael

brookspw · #4 06-03-2002, 10:14 AM

Trust me, it is simple. If you plan on keeping this car, or having another MB, you need to know this. These things eat brakes like I eat cookies.

To be honest, changing the rotors is easy, too. Trust me, do it once and from then on it will be a no brainer. Not saying that a technical issue couldn't pop up -- but just the maintenance part is easy.

brookspw

G-Benz · #5 06-03-2002, 11:29 AM

Not to make you feel inadequate or anything, but I let my 8-yr old daughter help me do the brake job on the 300E...it's that simple.

I'd let her do the valve job, but she can't carry the head around by herself...

MikeTangas · #6 06-03-2002, 11:55 AM

When you lift the car be sure to place it securely on a jack stand (or set of stands) before removing the wheel. DO NOT attempt to work on, under or around the car if it is support by any type of jack without the benefit of support stands.

That said, I don't know about the E's, but on the 4.5 I can change pads through the "window" without having to remove the caliper from the vehicle. Simply driving out the pins and removing the tensioning spring is sufficient for pad removal. In lieu of the "Mercedes" piston compressor I use the old pad and a set of channel locks to compress the caliper piston. Just be sure to compress and exchange one pad at a time leaving the other pad in place.

I haven't done brakes on the 560 yet (but I did check them during the resurrection 70%fr/90%r), so I can't comment further on the newer cars. Perhaps the wear sensors require caliper removal.

#7 06-03-2002, 01:31 PM

Thank you Everyone

If an 8-year old can do it, so can I!!!

Whats the tool called that compresses the piston into the caliper?

I think im now confident enough to try it...the only thing is, I don't need new brakes yet

ohwell, i'll do it in another few weeks!

Thanks Again

#8 06-03-2002, 01:50 PM

Oh and Do any of u guys suggest GreenStuff Pads? Sure there like $90, but it's cheaper than having someone put OEM pads on.

Thanks

Michael · #9 06-03-2002, 01:57 PM

Mr. Tangas,

The subject car here has a single piston floating caliper setup in front; the only "window" in the caliper is just large enough to allow connection of the wear sensor wire from pad to vehicle harness. Frankly, I think these are even easier to change the pads on, 1 bolt and a quick squeeze with a C clamp and you're done

Ali Al-Chalabi · #10 06-03-2002, 04:35 PM

Chris,

I like the feel of OEM pads and would recommend them. They are under $50 for the set of front pads at Fastlane at the top of the screen.

csnow · #11 06-03-2002, 06:01 PM

I do not wish to squash your enthusiasm in any way, but I have found it to be the rare case where the rotors are in good enough condition to just replace the pads.
In addition, grinding the rotors is sometimes possible, but requires an extra trip to some sort of machine shop, and the ground rotors may are more prone to warpage.
Considering new OEM aftermarket rotors are typically $35-40 each, I have taken to just replacing them at the same time as the pads. The money you save by doing it yourself makes the $80 relatively insignificant.

That said, replacing (front) rotors on a 300E is a snap!
1) Remove the 2 big bolts that secure the caliper to the steering knuckle (19mm head,92Ft-lbs torque). Remove the caliper. Do not let it hang from its hose. Wire it up, or set it on something (I use a milk crate-just the right height and size).
2) Remove the set-screw that holds the rotor in place (6MM hex key). Pull Rotor, replace rotor. Replace set-screw.
3) Replace brake pads as described in other post.

Extra credit projects for best results:
1) Apply anti-squeel paste to back of pads.
2) After cleaning with solvent and sandpaper as needed, apply a very thin coat of moly grease to the caliper surfaces that the brake pads slide on. Do not get grease on wearing surface or disk. Moly grease is often sold as "brake grease" in little tubes at the parts store.
3) Apply a silicone grease to the 2 pins (that go into the rubber boots). Most parts stores carry this stuff these days.
4) Bleed the calipers until the brake fluid runs clear. Pushing the calipers back in often forces the scummy fluid that has settled in the caliper (the lowest point in the system) up into the resevoir and the rest of the system. Ideally, you would bleed the calipers before pushing the pistons in. Brake fluid should be renewed annually anyways, so odds are that it is overdue when the pads fail.
5) Inspect the rubber hoses. Do not mess around with these- if they are cracked or have bulges, replace them. I replaced mine recently for just $8 each.
6) Remove, and clean the ABS sensor with brake solvent. It is magnetic, and accumulates rust filings on it over time.

300E brakes are very easy to service, but braking is serious business. This is a place where a little extra attention goes a long way...

#12 06-03-2002, 06:22 PM

rrrrr....more work
If so tho, and Ali said that he'd stick with OEM. But would they all together be Better brakes?
Since i might be into discs now, how bout these:

for Pads, these:

I would only put the new rotors in front tho, the rear brakes do nearly nothing.

Or does everyone say stick with OEM, i really don't mind spending a little more money for more power.

I do enjoy being able to stop faster

csnow · #13 06-03-2002, 09:37 PM

I have tried cross-drilled, slotted, and both. I honestly cannot say that I have noticed any difference.
From my experience, the cross-drilled in particular seem to wear out much faster. Seems that grit is more able to get into the works and dig very deep grooves in the face.
Maybe they would make difference on the track, or some other situation that would otherwise cause fading.
My opinion is that at $93 each they are not worth the money.

Now brake pads are another story altogether.
I have not used that particular set, but I have been very happy with other carbon fiber pads. As a class, they tend to work very poorly when cold, which can be particularly noticable if you have an automatic which is idling high in the cold. This trait can be downright unerving if your first attempted stop for the day is on a steep hill.
Also, these pads tend to require more pedal effort all of the time compared to OEM. In exchange, the stopping power is more constant and controlled. They are also less prone to squeeling. I have not found any of them to live up to the claim of prolonged rotor life. In fact, the pads themselves seem to wear out faster than OEM. No black dust is nice.
Many people do not like the feel of these things at all, particularly if they are not used to them. Many on this board have cursed them. I have even been told by occassional drivers that there is "something wrong with my brakes". Of course, the set you are looking at is about 3x the typical OEM price, so that is a factor.

I tend to splurge for sport pads, and stick with OEM rotors.

#14 06-04-2002, 09:50 AM

Thanks for the info csnow
Iv decided to just stick with the OEM rotors, im still debating on pads but i think i'll stick with the OEM's.

Also i noticed you had a 5-Speed 300E, how much faster would you say that is, than an automatic? On 0-60, iv gotten 7.6, thats my fastest...Thats with 1st gear start and removed resistor.

Thanks again

Michael · #15 06-04-2002, 10:54 AM

csnow/all,

I get 2 sets of OE pads to each set of rotors. This has been the case for 250ish k miles on my3 cars.With the exception of track days, I run OE everything. However, of note IMHO I've begun to cryo-treat the OE front rotors on my 500E and they seem to be considerably more durable-usually I warp front rotors after a day at the track, but the last 2 sets of rotors so treated have held up fine, and show minimal/no wear so far (too early to report on long-term durability)

As to my ignoring brake fluid quality issues in my earlier responses, please understand that my advice is given presuming near-new fluid is in the subjectr car's system. FWIW I power bleed each car each year (and an extra one after a track day), so I can get away with a 15 minute pad change every so often