Is anyone able to identify the source of this noise?

[miguel.edwardswr]

The brakes on my roommate's 2005 E320 CDI, which has 250k miles, have recently given him a run for his money. The problem, which we eventually identified as a bolt backing out of the D/R caliper, was preventing the car from moving forward because it was pressing against the inside of the wheel. Whatever the case may be, it took him some time to figure it out. We released the air he introduced yesterday as he chased it. My Modis Ultra has cleared codes all over the world, the brakes are nice and firm, and the car drives wonderfully.

Still, there's a grinding/screeching noise coming from the back. I told him that, considering all the drama, it would likely be worthwhile to find. He plans to remove the back wheels in an effort to diagnose the problem. Is there anything you can tell him to look for or suggest as to what it might be?

[miguel.edwardswr]

Additionally, how would you approach diagnostics? To find out which wheel is grinding, I'll start by raising them both into the air and manually turning them.

[max.petrovrm]

Is there any way to find out how this occurred? Can you think of anything comparable for the back?

It is my assumption that you are conversant with the SBC system's ins and outs. When working on the brakes of these vehicles, use extreme caution.

Assuming you could get your hands on the object in question, I would expect you to have no trouble identifying its source of noise.

[miguel.edwardswr]

Yes, I do think I can put my finger on what happened. A mechanic and skilled con artist lived next door to us. We would do our best to get him a job every chance we got since he was unemployed. Some of his sloppiness became more apparent after he moved on from the rich chic he had cheated on and shackled up with. His grip on the vehicle's brakes was firm. Personally, I don't think he used loc-tite.

Do you have any specific safety measures you would recommend for the SBC?

[max.petrovrm]

After that, you should brace yourself for the possibility that the brakes will need to be rebuilt from the ground up.

It appears like you may be lacking some knowledge when it comes to these brakes, as you managed to get air into the brake lines while fixing the front brake problem. Personally, I've never had that happen when replacing brake pads or rotors or fiddling with the calipers.

There is a wealth of data available regarding SBC systems, including how they function, safety measures to take, and how to operate them. Before diving into any system, make sure you have a good grasp of it. A cracked and broken piston in a rear caliper was my evidence that someone had obviously messed with one of these systems. Never risk serious injury to yourself or the brake components by working on an activated system; always turn it off first.

[miguel.edwardswr]

Yes, my friend was handling everything independently until I offered him some advice on bleeding a few days ago, at which point I became somewhat involved. He was griping about how soft the lines were, and the car was griping about how it couldn't brake as much, so I guess he let some air into them. We were bleeding them so hard that we couldn't tell if air was coming out because the Mity-vac wasn't making a good seal.

Before, I didn't notice them, but now they're all working well. After that, I proceeded to clear all codes globally with my Modis Ultra, and now it's driving wonderfully. So far, no errors or alerts have occurred again.

An SBC code was there before. We tried to take it to the dealer for a warranty repair, but they wouldn't touch it until he spent $3,000 on brake work that was unnecessary and out of his budget.