Brake pads? or something else? Squeaking... - PeachParts Mercedes-Benz Forum

azitizz · #1 04-10-2011, 09:45 PM

I'm wondering if squeaking brakes has to do with worn brake pads. They also seem to be less responsive than they should be.

It feels like you have to press harder to get the same stopping power. No brake light has come on, but to me that may only mean a bad sensor. The fluid level hasnt gone down and I recently replaced the MC with a brand new one.

My guess is the pads but are there other warning signs of worn pads? Or something else for that matter?

Thanks

leathermang · #2 04-10-2011, 09:50 PM

Might be a leak developing in your vac system to the extent that it is affecting your power booster for your MC.....
That should not affect squeaking .. but will cause you to have to press harder and then when it goes out ( vacuum pump or diaphram) really really hard just to stop ... it happened quickly to me...and I almost rolled through a stop sign pushing as hard as I could...

azitizz · #3 04-10-2011, 10:41 PM

Hmmm, not looking forward to a vacuum system inspection. Its been a bit of a headache in the past.

Is brake pad wear an unlikely reason for poor braking like that? They do sometimes feel soft. Its kinda hard to tell.

If I press it once slowly, it seems to go down far if I press hard. But if I press a few times quickly it becomes stiff with the pumping.

leathermang · #4 04-10-2011, 10:54 PM

You might have air in the system.... given that last description..

but Really !!!

These are BRAKES ISSUES.... Sorta Important !!!

and your car is pretty easy to replace the pads on...
you need to get down and check it.. or just put new ones on..

yes, brake pad wear is not the likely cause of your problems unless something is not functioning properly..
I assume you have checked the level in your MC .. like front and back levels ?

vstech · #5 04-10-2011, 11:18 PM

pressing once causing the pedal to drop points to either fluid loss or MC failure.
pressing multiple times causing the pedal to get hard is likely just a slow to recover vacuum issue.

leathermang · #6 04-10-2011, 11:25 PM

Quote:

Originally Posted by vstech

....pressing multiple times causing the pedal to get hard is likely just a slow to recover vacuum issue.

Could be slow vacuum issue.. but...
Isn't that the same situation encountered when bleeding brakes with a helper ?
Pressing several times ' pumps it up' then the fluid is released at the bleeder...
at the point where no air remains... pumping it does not cause it to get more firm...

vstech · #7 04-10-2011, 11:29 PM

yeah, but it's only getting firm from the previous bleed down situation. so air leak/lack of fluid could mimic the situation, but "hard pedal" is a different feel from "firm braking"

Skippy · #8 04-10-2011, 11:34 PM

I'm guessing there's air in the system. Bleed your brakes again. You did bleed them when you installed the new master cylinder, right? While you're at it, inspect the brakes and see if you see anything amiss, leaks, old-looking hoses, uneven wear, etc.

azitizz · #9 04-11-2011, 08:52 AM

I think I may do a thorough Bleed again. I did do one when I replaced the MC. I may get a new set of pads as well.

I see there are many different options for pads. With varying thicknesses. How do I know if I need a 15mm thickness or a 17.5 mm thickness for the front pads.
It seems there is only one thickness available for the rear.

I noticed I ave ATE rear calipers, but the front I couldnt make out anything but a mercedes star, so must be originals?

Does it matter if i get all one brand of brake pad or different brand pads than the calipers? (i.e. if I get ATE pads for the mercedes calipers?)

vstech · #10 04-11-2011, 09:19 AM

oh, can we know what kind of car, and what year please? it'll help with the diagnosis, and such...

azitizz · #11 04-11-2011, 09:22 AM

Quote:

Originally Posted by vstech

oh, can we know what kind of car, and what year please? it'll help with the diagnosis, and such...

Yes of course. Its a 1985 300TD Wagon. (its also written below my name on each post)

Thanks
Michael

vstech · #12 04-11-2011, 09:28 AM

Quote:

Originally Posted by azitizz

Yes of course. Its a 1985 300TD Wagon. (its also written below my name on each post)

Thanks
Michael

Thanks!
it's ALWAYS best to ad in the post body or the title the make and model! (this site keeps threads for years, and you are likely to change cars and user text over them! even the sig line changes made are changed on EVERY post ever made by you, so info in the thread really helps!

vstech · #13 04-11-2011, 09:31 AM

Quote:

Originally Posted by azitizz

I think I may do a thorough Bleed again. I did do one when I replaced the MC. I may get a new set of pads as well.

I see there are many different options for pads. With varying thicknesses. How do I know if I need a 15mm thickness or a 17.5 mm thickness for the front pads.
It seems there is only one thickness available for the rear.

I noticed I ave ATE rear calipers, but the front I couldnt make out anything but a mercedes star, so must be originals?

Does it matter if i get all one brand of brake pad or different brand pads than the calipers? (i.e. if I get ATE pads for the mercedes calipers?)

not sure on the pad thickness, I've never measured mine. but the brand caliper is irrelevant to the pads! usual suspects are ate and bendix. if the spring clips match your rears, then they are the same brand, if the springs are different, then they would be bendix fronts.

azitizz · #14 04-11-2011, 10:43 AM

Do you think it would matter what thickness I got? Would the thicker last longer because its thicker or is it simply the metal part attached to the pad that is thicker?
Thanks again

1985 300TD-T wagon

leathermang · #15 04-11-2011, 11:50 AM

The distance the pistons will retreat... leaving a gap of a certain and limited size...will determine the thickest pad you can put in ..

but the more thickness may not mean longer lasting...
the hardness of the material they make the pad from will make a huge difference in that...