Parking Brake Light Flases Upon Acceleration 83 300SD - PeachParts Mercedes-Benz Forum

eatont9999 · #1 11-14-2012, 09:33 PM

Hey fellas,

Here is a strange one. My parking brake light flashes when I accelerate moderately to hard. This is the red light by the way. I looked at the brake pads quickly and they look like they have meat on them. It would make more sense if this happened when braking but it only occurs upon acceleration. I am under the impression the low brake fluid light is displayed by the yellow light.

Where should I start?

vstech · #2 11-14-2012, 09:38 PM

you are under the wrong impression.
the low fluid light is the same as the light that lights up when the parking brake is on.
so, if you are low on fluid, but not below the minimum, hard acceleration could drop the fluid below the float trigger and light it up.

shadetree77 · #3 11-14-2012, 11:14 PM

could also be the switch at the parking brake; maybe it's a little loose, but definitely check your brake fluid level. the yellow light with the circle and hashmarks is for brake pad wear; once the pad gets down to about 1/4 material left it will light up

eatont9999 · #4 11-15-2012, 12:52 AM

Quote:

Originally Posted by vstech

you are under the wrong impression.
the low fluid light is the same as the light that lights up when the parking brake is on.
so, if you are low on fluid, but not below the minimum, hard acceleration could drop the fluid below the float trigger and light it up.

After posting, I went out and added some brake fluid. I thought the same thing about the fluid sloshing around. It turns out that you were right and I was low on fluid. The good part is that I found the cause. The bad part is that I have a leak in the system somewhere. I think it is time to rebuild the whole braking system in the next 6 months. The brakes are OK but I do get a pull to the left when braking and that sounds like a sticking caliper. It is cheaper to rebuild all the calipers than to replace them, so that is probably what I will do.

Suggestions on brake pad brands? I am looking at semi-metallic pads. Also, how terrible is it to have the rotors turned if they are still within the .765" or so spec? I know the left front rotor has a lip on the rim and that is probably not a good thing.

eatont9999 · #5 11-15-2012, 12:54 AM

Quote:

Originally Posted by shadetree77

could also be the switch at the parking brake; maybe it's a little loose, but definitely check your brake fluid level. the yellow light with the circle and hashmarks is for brake pad wear; once the pad gets down to about 1/4 material left it will light up

Thanks, good to know. I fiddled around with the parking brake and the light never went on, so I ruled that out first off. At least I know what light to look for when the pads get low.

vstech · #6 11-15-2012, 05:58 AM

if the rotors are that thin, just change them. they are not expensive, but are difficult to remove on some vehicles (123/126) turning them removes a lot of material, and weakens them and it's nearly the same price just to replace them!

Quote:

Originally Posted by eatont9999

After posting, I went out and added some brake fluid. I thought the same thing about the fluid sloshing around. It turns out that you were right and I was low on fluid. The good part is that I found the cause. The bad part is that I have a leak in the system somewhere. I think it is time to rebuild the whole braking system in the next 6 months. The brakes are OK but I do get a pull to the left when braking and that sounds like a sticking caliper. It is cheaper to rebuild all the calipers than to replace them, so that is probably what I will do.

Suggestions on brake pad brands? I am looking at semi-metallic pads. Also, how terrible is it to have the rotors turned if they are still within the .765" or so spec? I know the left front rotor has a lip on the rim and that is probably not a good thing.

eatont9999 · #7 11-15-2012, 12:07 PM

Looking at caliper rebuild kits, I see one for ATE and one for Bendix. How do I tell which I need? Is this something that I need to look at the part number on the caliper to find? Or is it something more obvious? I'm also assuming that any rotors sold on fast lane are good quality. I'll probably go with ATE, especially if my calipers are ATE as well.

vstech · #8 11-15-2012, 12:40 PM

you need to look at your calipers and determine which you have and order the kit for your brand.
it'll say bendix on them if they are bendix, I don't think ATE is as obvious. also, bendix uses retaining clip pins ate they just push out.

eatont9999 · #9 11-15-2012, 02:03 PM

Quote:

Originally Posted by vstech

you need to look at your calipers and determine which you have and order the kit for your brand.
it'll say bendix on them if they are bendix, I don't think ATE is as obvious. also, bendix uses retaining clip pins ate they just push out.

OK, thanks. I'll stick my head under there and see what I see and say what I saw. Then I will saw what I said and make a liar out of myself.

toomany MBZ · #10 11-15-2012, 02:42 PM

ATE and Bendix have different pad retaining springs for the fronts, both use pins, have a look.

eatont9999 · #11 11-15-2012, 06:39 PM

I can't see the calipers well enough with the wheels on. I'm going to have to take each wheel off to inspect the calipers in case one is different. Last thing I want is to assume something and have a brake rebuild project turn into a SNAFU.

My parts list:

4x Brake Disc Set Screw
2x Front Rotors
4x Brake Pad Wear Sensors
1x Set of Front Pads
1x Set of Rear Pads
1x Parking Brake Shoe Kit
2x Brake Fluid Reservoir Grommet
2x BFR Float Caps
2x Front Brake Hose
2x Rear Brake Hose
2x Front Brake Caliper Rebuild Kit
2x Rear brake Caliper Rebuild Kit

Pending inspection of rear rotors, can you guys think of anything else? My Master Cylinder seems to be fine but I will inspect it for leaks when I have daylight.