Ive spent the past few days doing abit of work on the tuning, and was making very good progress on it when it all started getting rather difficult today, the bloody brake booster has failed again, this time internally, the repair i did to the outer case is still fine, but the diaphramn has now failed, allowing a vacuum leak.

Its a ***** of a thing to remove from the car too, so the barstard can stay there until the other booster turns up for me to rebuild (Thanks Johnnymo63 ) and ill swap them over.

I considered fitting another brand of brake booster and master cylinder last time i had it all out, which would no doubt be alot of friging around, but whenever i drive the 95 Mercedes Benz C180 and see just how little pedal effort is required to stand the car on its nose, im impressed by the setup to say the least. The discs on that car arent real big, and neither are the calipers, the car weighs alot, the Lucas booster isnt any bigger, and the master cylinder is quite small, yet the brakes are extremly powerful....

 

Damn Case,

I empathize with your troubles. I believe that for some reason C4s were designed with a higher pedal effort than the pedal pressure in new cars.


Maybe someone will ask Gordon Killebrew about it.


My 95 can stop amazingly quick it just takes more pedal pressure than my Impala.

Mike

 

Yeah mate i know what you mean about the higher pedal force, thats not so much of an issue, its the components with a level of reliability that is questionable at best!!

Even though i only have the JL9 brakes, my car pulls up very quickly too when i want it to, but to be honest, i reckon it could be alot better considering this 95 Benz will pull up just as quick, if not a little quicker with smaller discs, smaller calipers, smaller tires, and lots more weight!!

 

Case,
I have a boss that has a bunch of mercedes cars, and sometimes I have to deliver it to the shop for him to get work done.
I talked to the tech, and he said Mercedes has a different philosophy on brakes.
Most manufacturers take the stand that you shouldn't worry about brakes until they need to be replaced, and they should be reasonably efficient and long lasting.
He said that in school, they told him that the rotors are disposable. They rarely if ever use the rotors over. The metal that the rotors are made of are soft, and together with the semi-metallic pads, and a secret friction material recipe, the brakes are more efficient.
You have to just replace more things when the brakes come due.
He said that Mercedes position on brakes, to save lives, when brakes are the difference between an accident and death, certain parts are to be considered disposable.
He said that to do a Mercedes brake job the way Mercedes technicians are taught,
1. throw away the rotors
2. replace all the calipers with rebuilt or new units
3. flush all old brake fluid from the system and replace.
4. use Mercedes factory rotors
5. use Mercedes factory pads
6. pressure test at each wheel to determine there are no blockages
7. repack wheel bearings
8. inspect the Master cylinder for external leakage
9. inspect tires and wheels for anomalies
10. clean the areas in each wheelwell and determine condition of
all parts associated with brakes, suspension, no obstructions.
11. road test and activate ABS,
He said there are no 2 wheel brake jobs, and they are forbidden to just throw another set of pads on, and turn the rotors.
He said there are more hoops to jump through, but at least the ones I could remember here will ensure like new performance from the brake system.
I probably need to flush my fluid . It's probably as thick as molasses

 

Case,

You think you may be a victim of that "brake computer"? Sorry, I read about the ABS having it's own computer that throws codes.....but not having that model myself, I only paid 30% attention to the details and all I can remember are vague theories of how it worked or went into limp mode making the brakes hard to activate. (was that a sentence or what?)

With all that brake trouble you describe, you think you may have this issue? I mean, it is worth looking into.

 

There is another member here who had a bad 'brake feel' on his Z from the day it was new.

He used a master cylinder off an LS1 Camaro. One fitting has to be changed, the fenderwell on the hood needs to be shaved very slightly to clear the cup. Said to double check the rod length, I think he made a shim about 20thou thick so the pedal doesnt drag the brake.

Said it gave the stopping power as you described on the benz...Only these are cheap. You dont use the wire that attached to it from what I understand.

 

Coupeguy2001, Mercedes Benz servicing is slightly different here, the standard procedure is simular to what you described, however you can ask for a more basic job and they do that.
Nothing what so ever to do with the EBTCM, i know for a fact its a failed brake booster.

The EBTCM is the computer for the braking and ASR systems, and its codes are read through the CCM with the paperclip method and displayed on the LCD panel as module 9. There are no DTCs cause the electronics are working perfectly fine, it has no way of knowing the booster has failed internally.
I might have to look into it and see what the story is there, although i think youd be suprised how dirt cheap the Lucas booster used on the C180 is (a shade over $75 AUD).

Which wire are you talking about being attached? My master cylinder is on the right hand side so i dont know if i have more space or less space than a stocko lefty, ive never taken any notice to the clearance there, ive got a fair bit on mine.

 

Just as long as you know what your doing, you sound like you do

 

Thanks mate, ive got a pretty fair idea Your input is allways welcome