So, replaced the brake booster, or rather paid my mechanic to do it.
His labor came to $550 or 5.5 hours.
I originally decided to have him do it, as I saw a video on youtube where the master cylinder had to be removed to get the brake booster, which means, bleeding air all the way through the system, and I don't really have any place to do that.
So, in the end, he didn't end removing the master cylinder, just pushed it aside. You have to remove bits of the firewall, and the windshield wipers and motors to get to it, as well as moving the fusebox out of the way.

I can't help but wonder if I should have done it myself. 5.5 hours seems a little excessive to me for a purely mechanical replacement, as in just unbolting sheet and putting it back.

That being said I have a long time relationship with this guy and I trust him, and he didn't have a problem putting in a used part (got a booster from a 2005 C230 for 50 bucks from a junkyard and it works great!). Also he's given me advise over the years, and done a few things no charge like setting Xenon to present and clearing SRS errors and I'm able to call him and bend his ear on problems I'm having and advise on fixing them, even if I'm doing it myself.

But damn, i dropped it off at 9, went by at lunch, and they just needed to button it up, it was mostly done, so where'd the other 2.5 hours come from? They broke for lunch at 12, so that means it was mostly done in 3 hours. Putting the firewall pieces and wipers back in couldn't have taken more than an hour. I feel I could have done it in that time. But oh well too late now.

Hoping it cures my P0171 too lean error so I can pass smog.
Old booster was leaking like a banshee, you could hear it hissing inside the car. Brake are working much better now.

 

Glad you got it fixed!! I have had similar billing issues with some dealers who charge more hours then it obviously took. I had an issue where a dealer (unnamed brand) tried to charge my family twice for a rear brake job. They put down that it took 1 hours to do front brake pads and 2 hours to do rotors and 30 minutes to bleed the system? In reading the description of the rotor's 2 hours of labor it covered removing the pads and doing the system bleed. They also called and said car was ready under 2 hours after dropping car off lol That said we only paid for parts after talking to corporate but I wonder how many times they had done that to others?

 

Well, my readiness indicators are finally set as of yesterday, and no P0171 error!
It's off to the smog shop I go and then to AAA to get my tags!

Brakes are working much better, and also it seems to run better.
Guess all that air was really screwing things up.
My local dealer wanted 325 an axle to replace pads, no rotors and + parts and that was like 10 years ago. Ha!

 

Glad you got it fixed coupe! As you found, vacuum leaks in with the brake booster degrades the engine and braking performance.

You get your tags from AAA!

 

You must have a lot of buttons!

You still on the original pads/rotors? I just had mine done, after I'd say about 6-8 years or so? The C32 brakes are obviously way too much for our cars. But it's nice to not have a shaky steering wheel anymore when braking.

 

Hooray I finally passed smog! And got my tags all it took was a new catalytic converter two
New oxygen sensors and a new brake booster. Original brake pads? Are you kidding? No I'm on my 3rd set of rear pads 2 sets of the original fronts Plus 2 sets of stock c32 pads before going to ceramic pads which now have been on there one hundred and thirty thousand miles. Pretty amazing?

 

Those ceramic pads are pretty cool, eh?

 

Yeah, I've been sitting on a new set of pads and rotors for several years now but don't actually need them yet. Still like 1/2 the pad left.
Rears are Akebono's too now.
GF's ML is now all Akebono....cracks me up when people say, they're worried the pads will mess up the rotors. Stupid. If you're going 100K + between pad changes, who cares, you'll be changing rotors anyway.

 

So you guys are using OEM rotors with ceramic pads?

And I don't remember if I had asked this before, but
can one only put ceramics on the rear axle and keep the oem dusty pads on the front?
(don't want to replace the still OK fronts)

 

I run C32 brakes, with OEM rotors and ceramic pads.
Rear I have EBC slotted and dimpled rotors in a feeble attempt to look cool, and kinda match the fronts but in reality a waste of money. The holes full up with brake dust, and when you go to the car wash and they get pressure washed clean, the insides of the holes just show rust.

If the rears ever need replacement (also ceramic) I would got back to OEM rotors.

 

That should be fine. My Akebonos seem to bite as well as the OEM pads (though they had a slightly different feel as I remember).