126 Soft brakes - PeachParts Mercedes-Benz Forum

Putty · #1 02-15-2009, 12:04 AM

So today I changed my brake pads on my 86 300SDL...first of all, these have got to be the most annoying pads in the world to change!! Second, whats weird to me is that after I changed the pads, now the brakes seems to be too soft...almost as if they wouldnt fully bring the car to a stop in an emergency but still stop the car.

I dont know why though...I didnt open up the system to change the pads...how could air get in?

However, when I changed the pads, to get the piston to recede so I could slip the caliper back on the rotor I used a C-Clamp...would that have made air enter the system?

What do you think?

Johnhef · #2 02-15-2009, 12:12 AM

How much have you driven it since the change? They need to be driven to get the pads to seat on the rotors. Also cheap pads will give the feeling you describe.

Putty · #3 02-15-2009, 12:14 AM

Wearever Silvers from Advance Auto...22 bucks a set. Only had em on 7 hours...it would take them longer than that to set?

sixto · #4 02-15-2009, 02:48 AM

Quote:

Originally Posted by Putty

these have got to be the most annoying pads in the world to change!!

I can't think of easier pads to change.

Sixto
87 300D

compu_85 · #5 02-15-2009, 02:48 AM

The brakes on my SDL are some of the best brakes I've had, and I've driven a few cars. I put cheap pads on my TDI the last time around, and I've been regretting it ever since.

I would dump the cheepie pads and try to get some quality ones. They're worth the extra $$$. Your brakes are your most important safety feature.

-Jason

pawoSD · #6 02-15-2009, 03:42 AM

Thats not necessarily true. I put autozone Duralast pads on the front of my SD for my pad-replacement last year.....and they stop BETTER than the OEM (MB star) pads that I had on prior.....and way less brake dust too.

Cost of MB pads? $50 a set

Cost of Duralast? $19...and they're made in USA I got them free because I had a rewards credit! They even have the sensor hole drilled in them.

I put them on my bro's 300D too, and it will easily lock up the tires (as will my SD).

Duralast pads = good!

I will consider them for our W124 soon as it needs new brakes all around (due to corrosion).....

tyl604 · #7 02-15-2009, 09:18 AM

Use of the C-clamp would not cause a problem. This is the easiest way to push the pistons back. Assume you left an old brake pad in between the clamp and the piston?

Putty · #8 02-15-2009, 09:32 AM

no, didnt use an old brake pad...just caught the edge of the piston and applied pressure slowly until they receded...

leathermang · #9 02-15-2009, 11:14 AM

Quote:

Originally Posted by Putty

no, didnt use an old brake pad...just caught the edge of the piston and applied pressure slowly until they receded...

Well, for those doing this sort of stuff in the future...that is not the recommended situation... it is best to place pressure as eveninly as one can when applying backwards movement to that piston... The tools available for applying that pressure are made to work in that manner.

If it feels soft your best quickest and cheapest first action is to simply flush / bleed your brake fluid. It is sometimes possible to push dirt or air into the caliper ... so if that happened bleeding should fix it.

compu_85 · #10 02-15-2009, 11:50 AM

And you should be bleeding the brakes at least every 2 years anyway.

-J

Johnhef · #11 02-15-2009, 09:13 PM

Quote:

Originally Posted by compu_85

And you should be flushing the brakes at least every 2 years anyway.

-J

compu_85 · #12 02-15-2009, 11:10 PM

Thanks, that's what I meant.

Putty · #13 02-16-2009, 09:07 AM

Alrighty then...I'll flush and bleed and see what happens. I'll post results soon.

And if Im not mistaken...the way to bleed the Merc brakes is rear passenger then counter-clockwise.

leathermang · #14 02-16-2009, 10:28 AM

The way is to start with the longest brake line 'measured along the line' from the master cylinder. This may vary on different cars.. it can be routed differently from one model to another.. from one year to another... so best to look at how it gets to all the brakes...
When you do it this way after the first one there is clean fluid at the start of their line...
I do not know enough about MB to say which way it is... this rule applies to all cars defined this way...

vstech · #15 02-16-2009, 11:03 AM

actually, it's best to get a power bleeder, or make one from a block of wood and a pressure sprayer... anyway, it's best to fill the bleeder with clean brake fluid, and pressurize the system slightly. like maybe 10 pumps on the sprayer, not over 10 psi... then just open the furthest bleed screw, and let it flow the dirty fluid out, until it flows clear fluid, then continue to the rest. all done, no fuss.