Part name and number highly needed - PeachParts Mercedes-Benz Forum

MBSL560 · #1 10-15-2011, 05:44 AM

Hello,

I went today for oil change and check up and then suddenly the brakes stopped working. They have touched the brake fluid box.
Now they are telling me that the rear tires never received brake fluids!!!!!!!!!!!

I am in need of the name and part number of that metal thing which sits below the brake fluid plastic box. Can I even buy that as single part or is it together with the plastic box? My car is a Mercedes SL 560 from 1987 and american style. The parts are therefore different to the same cars built in other countries.

I had to leave the car back at the shop as I could not use the brakes! That was scary.

I hope you can help. I also took pictures of that part in my car. Please have a look at the whole and the pic as a close up of the metal part.

thanks a bunch!

mbboy · #2 10-15-2011, 06:55 AM

The metal unit that sits under the brake fluid reservoir is the master cylinder, part # 004 430 75 01. Its readily available as an after-market part at any place that carries foreign car parts for well under $200.

I'm not sure how or why they determined that the rear brakes weren't operating. Did you try the brakes to see if they still operate, or did you just take their word that the car wasn't drivable? Is the brake pedal still high and pressurized when you turn the car on and you step on the pedal? Or does it go to the floor?

MBSL560 · #3 10-15-2011, 07:06 AM

Hi

thanks for your reply.
I looked also online to find out and it says it is brake master cylinder.
I found some for 75 dollars only and new.

Well. They have took off the tires and checked it with something. I believe now that they checked the brake fluids. They told me then that they cannot change the brake fluid as the part mentioned does not provide the rear with the brake fluid. They told me that is maybe why I have problems to brake when they get hot after driving for a few hours such in serpentine, mountains, going downwards. I had to push brakes 3 times then to get the brakes work.

Well, after everything I sit down in the car, started the engine and used the brakes. The thing was that they did not apply at all. I could push the brake panel down. Also the brake light went off (in red) and that was the point when I said that I am not driving the car back home.
They started to take off a little part from the brake fluid box and pushed the box around and took the switch out and in etc. Then they said i can try to drive it home. No way!! That was too dangerous as the brakes could stopp at any time.

Due to the cylinder which did not provide the rear with fluid, they told me to get a new part and replace it. That would be better. But in my country they dont have those parts as they built the same car differently.
Mine is american...

To answer your question. Yes, the brake pedal went all down to the floor. brakes did not apply. And to me it is not safe to drive it like that also after they played around with the fluid box and telling me that i should replace soon and be careful as it could stop working just like that.

it is hard to get the car proper down in a country where you cannot just get parts and if, they are more than 2 or 3 times expensive than in america. Cant pay that all the time...

MBSL560 · #4 10-15-2011, 07:51 AM

the check up of the tires: one sat in the car and the other one was with the tire and put a thing inside (while tires off). dont know how that works, but it probably took them more than 30 minutes to do that.
I am not a mechanic.
I am curious in getting to know how all that works.
Dont know how the fluid is distributed and shows up at/on the brakes or tires. Is there a sing of fluids there so that they can see it? hmmmm

The brake fluid has to go to all four tires and brakes or not? Only to the front?
Not that I am buying a part which I do not really have to. I will re-ask when I have to go back to the service garage and ask. Mostly mechanics assume and do not know for sure which part really has to be replaced or if.
With a SL it is all vaccumed tubes around. Easily to have one or so not working...

engatwork · #5 10-15-2011, 08:20 AM

Quote:

Mostly mechanics assume and do not know for sure which part really has to be replaced or if.

hmmmmm

Brakes work like a hydraulic system. Fluid in the reservoir gets pushed to each wheel when you press the brake pedal.

What you are describing sounds like they were trying to bleed the brake system. The mechanic at the brake calipers opening a small valve trying to get fluid out while the other mechanic pressed the brake pedal. When he opens the small valve brake fluid should come out. If the fluid is not changed every couple/few years it causes problems at the calipers like what you are seeing. Ask them if they can rebuild a brake caliper.

Where are you from?

rowdie · #6 10-15-2011, 10:14 AM

Just because yours is a U.S. model does not indicate all the parts are different. The other SLs, 300, 420, 500 and 560 manufactured after 9/1985 through the 1989 model year share many of the same parts. This master cylinder is the same for all of the above.

A competent garage should have a power bleeder for bleeding the brakes.

nobby · #7 10-15-2011, 04:01 PM

Quote:

Originally Posted by rowdie

Just because yours is a U.S. model does not indicate all the parts are different. The other SLs, 300, 420, 500 and 560 manufactured after 9/1985 through the 1989 model year share many of the same parts. This master cylinder is the same for all of the above.

A competent garage should have a power bleeder for bleeding the brakes.

ABS unit might be pooched as well. Others have had luck bleeding the rear brakes with the ignition key ON during the bleeding process.