Working on brakes: how difficult?
 

I started as a newbie DIYer over the past several days: engine oil change, transmission/differential fluid changes were made easy thanks to your precious advice here...
I now need to inspect my breaks and possibly replace some pads and do whatever adjustments are required: how difficult is all that for a beginner such as myself? Is it enough for me to rely on the Haynes W123 book or do I need more? I would much appreciate any pointers you can give me, mentions of special tools that are required, useful warnings, etc.

Thanks
Rino

I dont know what breaks are but brakes are pretty straight forward on any car. Just remember the fluid reservoir has a wall in it seperating the from from the back (to prevent total fluid loss if the front or back lines busted).

I try not to work when on break. ;)

But they're not bad at all. Replacing pads is easy, I'd do the hoses while you're in there too. Flush the system too. Also check the rest of the system out for issues... rotor thickness, e-brake functionality, etc.

The brake pads for example are an extremely easy design to change on mercedes. So go for it. If at any time you feel uncomforatable with any procedure just ask for help on the site. That is one of the primary functions of this site. The flipside is you will be able to help others yourself down the road. Your manual is quite helpful in it's brake section as well. .
Try not to ask questions about engine oils though. :D Instead just search the archives. There is nothing like an oil question to get the feathers flying around here. :eek: It almost becomes irrational at times in fact. :)

Brakes are not a hard deal at all if you see it done. I just came out with the Front brakes DVD that shows you how to do the job right.

You can do it.

Thank you guys for your advice. I am a beginner and find the thing a bit confusing... Bleeding the brake system for instance... Do I buy a power bleeder, do I use the traditional method (a second person pumping on the brake pedal), do I make my own device? These are the types of puzzling choices I was referring to. I've never done it, so I have no idea how difficult and would appreciate some practical pointers. Can I do the work jacking up one wheel at a time? I don't have standing jacks and there's really no extra space I can use in my apartment or common-area garage for that type of thing... Is it something that requires a lot of extra special tools? In which case I'd probably be better off taking the car to someone to perform the job for me. Oil change, transmission/differential fluid change were easy... but brake maintenance... I need to find out if it is something within my reach and something I can do without spending a fortune on specialized tools... it is on these points that I'd much appreciate your opinions and suggestions...

Thanks,
Rino

Hey, I know what breaks are, but what the heck is from from.....:D :D

Haven't done brakes on the Mercedes yet, but have on other cars. Its really useful to use jackstands to take both front or back wheels off at the same time (you don't want to work under a car on a jack anyway), that way you can bring both rotors to be turned at the same time. You can get small jackstands for passenger cars for around $40/pair, and they don't take up much room when stored. Throw in a flat piece of wood and you've got yourself a coffee table! :D

Disk brakes are pretty easy, but you may need a c-clamp or something to push the caliper piston back into the caliper, since your new pads will be thicker than the old ones, you'll need the extra room.

If you've got a second person handy, have them pump up the brake pedal while you bleed...I like that better than the one-man bleeders anyway, but that's just my preference.

Good luck.

Since you've successfully accomplished the other tasks you should have no problem with the brakes.

You need to buy some jackstands as you will have to remove the wheel. Knock the two pins out of the caliper, remove the retaining clip and slide out the old pads. Push the piston back, insert new pads, retaining clip and pins and you are done.

Do it yourself, save the money and take pride in working on your own car.

Good luck.

Scott

Refering to brake bleeding, two person method works fine. Down side, it takes two people...Okay, pads straightforward. Channel locks to push calipers back, ONE AT A TIME!!! Keep one pad on to hold other. Tools needle nose pliers to remove sensors and cotter pins. Punch to drive pins out. Hammer, ball pein. Pull retaining springs. 19mm socket, not normally in set.

I also recommend jackstands... that said, a large block of wood under the frame of the car with the car on a jack is kinda ok... for 50.00 you can get a set of jackstands with a nice 2.5ton floor jack at most auto parts stores, or sears.
as far as bleeding goes, theese cars are so simple. with the cap off the MC suck out the nasty fluid, and fill it with clean fluid, then starting at the back passangers side, open the bleeder screw, it's either 8mm or 10mm, I don't rember... anyway, the system will trickle out gunky fluid, when the gunky stuff stops and you get clear, close her up and move to the closer to the drivers front. RR, LR, RF, then Drivers front. keep filling the resivoir. it is faster with a power bleeder, but not needed on the older MB's.
if you want to just change the brakes, it's also simple. just pull the clips, on bendix calipers, or simply drive out the pins on atx calipers. and pull out the pads.
reverse to install. some put stickey goo to keep the squeel down.
some use a sticky spacer.
ymmv
John

There are actually more downsides to the two person method. It requires that the bleeder valve be frequently opened and closed. This causes wear on it and also opens the sytem to possibilities of air getting sucked back in.

Just find a jar and appropriate sized hose. Fill the jar with some clean fluid and make sure one end of the hose is in the fluid. Attach the other end to the bleeder. Lift said jar above the bleeder (so the air flows up) get in the car and start pumping on the brakes. Keep an eye on the fluid level (remeber the rear reservoir) and try to keep an eye on the jar. I prefer to pump until its a nice clear color. Get out close the bleeder and move on. No reason to spend even $5 on a 99 cent solution.

Thanks for your advice... I'll get the jackstands at Sears this weekend (any specific suggestable model I should be on the look for? Preferably economical, reliable, and SMALL, so that I can hide them somewhere after use...) and I will look into all you have suggested, with the help of my Haynes manual to make sure I understand everything correctly, and then report back here soon.
While I am at Sears, what are the other special tools I am going to need that I should get there (I have no tools that are specific to brake work).

Winmutt, I am unclear about your 99_cent solution: does the jar you mentioned imply the use of a power bleeder along with it, or can I just use the jar and do the bleeding myself without the aid of a second person? Thanks...

Rino

What is this actually called?

No Bleeding
 

Replaced the brake pads a zillion times and never blead the calipers. Only if a hose is replaced.

The latter. You want to keep the jar ABOVE the bleeder valve. As you press the pedal in it forces the air out, then you release it sucks fluid back in. Just make sure you close the bleeder before you unhook the hose.

I got the jack stands and floor jack yesterday at Sears... I'm all set to go with the brake job...
How long would it take for the system to trickle out the gunky fluid and to complete the bleeding process using your method, more or less? I am willing to give it a try (if it works, I'd say it is the very best approach to brake fluid bleeding, in that it is done without the need for a power bleeder or the assistance from others...) I'd also like to learn more about what was suggested by winmutt, which process I do not completely understand at this point, but think that perhaps might be usefully used in conjunction with what you have advised...

Thanks,
Rino

As I mentioned, I got both the jack stands and the floor jack: I am ready... I want to give your method a try, and yet at this point I would like to understand better how that works before going ahead with it. My understanding (please correct me if I am wrong) is that in order to get the air (and the contaminated fluid) out of the system at the time of doing the bleeding, the new fluid has to flow from the master cylinder all the way through the exit points at the bleeder valves, replacing the old as it travels down. So, has the method you described to be done in conjunction with the process described earlier by vstech, that is, first empty the reservoir, refill with new fluid, start letting the old fluid in the lines out, beginning from the farthest valve, then RL, FR, FL... filling the reservoir with new fluid as it gets low... until all gunky liquid is out? Is it at this point that you do your thing with the jar filled with new fluid held above the bleeder valves and the pumping on the brakes? Otherwise, if you don't do the other part first, how is the old fluid going to be replaced and any air possibly trapped along the lines from the master cylinder to the bleeder valves going to be expelled from the system?

Please pardon my inexperience about the topic at hand and be patient, you guys... Both what you and vstech have suggested seems superior to the other methods posted here involving power bleeders or the traditional use of an assistant (to pump on the breaks - with the resultant wear on the bleeder valves)... but I need to fully understand how it works before I can do it appropriately on my own.

And, if you know of a website that explains this process thoroughly (maybe even with pictures), by all means let me know.

Thanks,
Rino

Agree with The Gears, no need to bleed unless you remove hoses. HOWEVER, brake fluid absorbes water very eaisly. A good maintainence item, as water soaked fluid will eventually rust calipers, then you get to spend even mo money. You may have heard, maintenance, maintence, maintence. This is part of it. This time of year may prohibit this. See three sentances ago. The resevoir has a passage way in the bottom. It is odd, I didn't believe it either. Just keep it topped up.

just dont wait too late. i burned through a pad once and prying it off the disk rotor was probably an 8-10 hour job and infinitely frustrating. i dont know about the w123's but my w126 has pad-wear sensors that need to be purchased & installed as well.

Good point, rektide, 123's have pad wear sensor too. Not a bad idea to replace. Cheap and available from most sites, some of which will alert you to other needed parts when purchasing items for whatever job you're doing.

Update
 

Just to confirm that, as many of you suggested, it is really very simple... you just need to do it once to realize its simplicity...
This morning I changed the brake fluid (using the gravity method), then took the brake pads out, played around with the caliper, put the brake pads in...
Thank you so much everybody for letting me know how to do it and that I could do it...
It's a wonderful support forum that we have here!

Rino

When replacing the pads, what's the best way to get rid of the brake pad dust that accumulates inside the calipers? It is likely to contain asbestos which is very hazardous to your health... so you don't want to use compressed air, risking to inhale it... I heard of some people washing their brakes as well when they wash their cars... Pouring water over the calipers... does it make sense?

Rino