My brakes are driving me insane!

[js81]

Title says it... here's the issue:

Replaced my brakes all around back in late April - new rotors and pads in front, new pads in back. All worked well EXCEPT after the switch I noticed that my front right is dragging. Not bad, but just enough to hear it rubbing and the car pulls slightly to the right on the highway. Not sure if this started with the brake job or not, but I hadn't noticed it before.

Here's what I've done:
1) Replace the rubber brake hose. Thought I'd start with the easiest first.
2) Replaced the entire caliper assembly.
3) Gone over it 6 different times. Tried different rotors and pads, as well as combinations of parts of the caliper.

NOTHING seems to fix this. Took to my local mechanic (NOT a Benz guy, but we don't have anyone that is in my podunk town) and he looked it over and drove it and seems to think its an alignment issue. Personally, I'm thinking master cylinder (because I've replaced everything else).

Thoughts? Should I take it to them and allow them to do the alignment or would I be wasting $30-40 that I don't need to spend when I'll end up replacing the master cylinder anyway? Thanks!

[arar_hany]

I would suggest you to do an alignment and check the psi on the tire as well.

[js81]

I would suggest you to do an alignment and check the psi on the tire as well.

PSI is good (28 PSI, recommended for my C220). Per my first post, how and/or why would an alignment help? There's no tire wear and as far as I'd noticed, car was driving straight and true until I disassembled the brakes. If there's a reason why the alignment would help, I'm totally game - otherwise, I see no reason for wasting $30-40 on something I don't need. Speaking of things I may or may not need, I got my master cylinder yesterday, btw - plan to install tomorrow.

[Vetruck]

Your master cylinder does not pinpoint pressure to just one wheel on the car. that is not your problem.

When you say dragging? Can you feel it or are you just throwing that term out there because you may hear a little noise from new pads and rotors seating? How do you know it's dragging? All pads stay in constant contact with the rotors at (pretty much) all times (not going to get into pad runoff in racing conditions- does not apply here)

I will say you have an alignment issue and you are wasting money and time on a MC replacement.

[js81]

When you say dragging? Can you feel it...

YES - I'm aware of how brakes work or else I wouldn't be doing it myself OR driving an 18+ year old car. :-p That stated, I jack it up, spin the wheel, feel resistance that isn't there on the other three, as in the wheel doesn't spin freely like the other 3, or any other car I've ever done a brake job on for that matter that didn't require a caliper/hose replacement (which I've already done).

If it's alignment, why would it have only started AFTER the brake job? Car drove straight and true beforehand. The bolts on the caliper and bracket were VERY tight and I had to push a great deal to break them loose; any chance that could've screwed with the alignment? I can't imagine that I pushed hard enough on it to mess up the alignment, but then again anything is possible.


Your master cylinder does not pinpoint pressure to just one wheel on the car.

That is my understanding as well. But as I stated above, I've tried pretty much everything else other than the alignment (which I would have to take it to someone to do - something I don't have time for, nor money to waste on). I purchased the master cylinder already because I got it for a very low price ($30 with 30-day warranty), so I thought why not (which in retrospect will be ironic if it is indeed alignment).

[vaspen]

I would tell them go ahed and do the aliment but if it doesn't fix it your paying half but if it dose you will pay full price
you did bleed the brakes on all 4 after changing the lines right ?

[Twichel04]

Could be a wheel bearing. It may just be a coincidence that it went bad at the same time you did the brakes... stranger things have happened.

[andy_1100]

I'd start with the wheel bearing, like Twichel04 said. Pull the brake pads out and then spin the wheel. Also check the brake caliper, used brake pads are thiner, so the piston is pushed out more. When you've installed new brake pads you've pushed the piston back, might be some rust or durt prevents the piston from being pushed back to create some clearence and that creates the drag.
Master cylinder and alighnment would be my last things to check.

[js81]

I'd start with the wheel bearing, like Twichel04 said. Pull the brake pads out and then spin the wheel. Also check the brake caliper, used brake pads are thiner, so the piston is pushed out more. When you've installed new brake pads you've pushed the piston back, might be some rust or durt prevents the piston from being pushed back to create some clearence and that creates the drag.
Master cylinder and alighnment would be my last things to check.

Still fighting this... need to take it to the shop, but I'm too stubborn lol. No noise when pads are removed at all; have already replaced caliper (exact same issue with both); bled lines multiple times, too. Tried to replace master cylinder, but the replacement was the wrong model (my fault, not seller's - I didn't realize that MB changed the line size for the rear at some point between 94 and 96. I am starting to lean toward the MC though, because after pulling it all apart it worked great - no dragging, no noise, only a slight pull which might actually be alignment - FOR ONE DAY. Now my pedal is extremely squishy and needs a LOT of travel. Gonna re-bleed everything this weekend. If that doesn't fix it, I'm just gonna take it to my mechanic - I'm done with fighting this.

[mbsickness]

Since you have eliminated the caliper and hoses I would look at the ABS pump. The fluid goes through there and if not mistaken the brake proportioning happens in there as well. Durin your brake job some debris could have gotten dislodged and is now blocking a passageway.

[syncview]

yes the brake proportioning happens in the ABS unit

[js81]

I THINK I may have it fixed. Decided to reassemble and bleed everything one last time; had done this at least 3 or 4 times already. Ended up bleeding a LOT more than I needed to (added at least 8-10oz of brake fluid over the course of it) and now the problem is all but gone, except for the pull to the right (which must've been alignment all along). Only issue I have now is an occasional "chirp" from the LEFT-front that is very intermittent and only at VERY low speeds. I'll deal with it - the brakes feel better than they've felt in months. :)