W124 400E - Brake Warning Light and Washer Pump Questions
 

Hi there,

Couple of questions for the meisters out there:

1. Today the orange brake warning light (the one with the circle with the dashed lines around it) was flickering when I stepped on the brakes and also when I was driving downhill. It seemed to do it more the more the car was nose down (heavy braking, steeper hill) or at least it seemed that way to me. The brake fluid level is fine (if anything, it is a little over the max) and there appears to be plenty of meat left on the pads (Only able to see the outer ones through the rims). Is there something I am missing here?

2. I needed the wash/wipe function today. Wiped (smeared) fine, but no fluid. The reservoir is 3/4 full, I made sure to use a needle on the nozzles in case there was any wax in there, still nothing. Do the pumps go bad? Or do they make a noise when they are trying to pump - I guess I can get my wife to wash/wipe while I try to listen. Ideas?

Thanks,
Jim

the brake sensor's either shot or you need new brake pads..

Your brake sensors are telling you that it's about time to change your pads...not sure if the 400E has rear sensors too, but you have front sensors at the very least.

From experience, you can probably get another 1500-2000 miles out of the current pads unless you are racing. I waited two months at one point before I swapped pads and I saw plenty of meat on the old ones when I did.

I had a pump go out on a 95 SL once...similar issue, no fluid despite full reservoir. Pump was $30, 15 minute job at home to replace. Worked after that.

Thanks for the suggestions.

Driving to work today (46 miles) I noted that if I am stopped and hard on the brakes the light stays on bright. But if i don't push down very hard, it lights kind of dim and flickers. The brightness of the light corresponds directly to the pressure on the pedal. Just cruising the light is off.

Jim

the 400e does have rear sensors as well.

That's the way the brake pad warning light works. The pad sensor wire completes a ground circuit through contact with the brake rotor (usually the ridge on the rotor that hasn't worn due to lack of contact with the brake pad friction material). The harder you push the pedal the better the contact. When the brake is released the light may or may not flicker depending on how much play you have in your wheel bearings and whether you are driving around corners. Although you can go quite a while with the light lit (esp. if the rotors are worn since the light comes on very prematurely) if you drive too long the warning light will cease to opearate since the sensor will be worn all the way through. Also if the pads get too thin the friction material can separate from the pad backing plate causing all sorts of problems.
When you replace your washer pump be sure to replace the rubber grommet that the pump inserts into---these always seem to leak when the pump is removed and reinserted or replaced. Mark

This and other systems are explained in your owner's manual. It's a good plan to read it.

Steve

Thank You
 

Thanks for the informative responmses, I appreciate it. I purchased the car recently, but it did not come with a manual. I currently have one on order, obviously I plan to read it cover to cover once it gets here.
Thanks,
Jim