ss3964spd

Haven't been on here in a while, but since my 2011 E550 met an untimely demise on fathers day I now find myself in a 2014 CLS 550, with only 11K miles on it, that I purchased just over 4 weeks ago. The word "immaculate" doesn't do it justice.

It does, however, have an odd issue with the brakes. Once the car comes to a complete stop and while maintaining just enough pedal pressure to hold the car still, the brakes actually release a bit - enough to allow the car to move. Adding a bit more pressure, without activating Brake Hold, stops it again and it's fine for the remaining time it's stopped. It does this every time I stop UNLESS I am using extremely light pedal pressure while rolling slowly to a stop, or if I activate Brake Hold immediately upon coming to a stop.

It feels like Brake Hold is activating and then partially releasing, or partially activating and releasing.

Anyone here experience the same?

Dan

Agent-A01

Has the brake fluid been flushed lately?

ss3964spd

I'm not sure why that would matter at all, but the dealer I bought it from is the dealer that sold it when new and has performed all the service on the car. I have all the service records; yes, the brake fluid has been flushed twice.

OBP

14 CLS550 here. 34 k miles. Don't use brake hold at all and never experienced what you describe. I am on after market pads and rotors now and did one or two brake fluid exchanges using the OEM fluid. I like my brakes right now.

ss3964spd

Thanks OBP.

I love the brake hold feature, use it all the time. The OE brakes have plenty of power, easily exceeding the traction limits of the tires, and though they feel fine hauling this barge down from speed they are exhibiting very minor signs of dreaded "warped rotor" (actually pad material deposits) at very low speed. It hasn't gotten worse but, if it does, I know the cure.

Regardless, none of that has anything at all to do with the actual symptom I tried to describe above, which is coming to a "normal" (not hard, not soft) stop without engaging Brake Hold, and a few seconds later the brakes will release. Perhaps not completely but enough to let the car move. It's weird.

cls5504matic

On some Toyota’s and such you can see if there is a leak by stepping on the brakes a few times with the car off in park etc. each time it should get harder and it should be very stiff by the third push.

If not I’d run the pressure loss down.

Tbbt CLS

ss3964spd,

You have stop/start with your 2014. How does it move forward with the engine off? Are you giving it a slight amount of gas peddle at stops and holding the brake at the same time? If not, this is odd indeed. Marv

ss3964spd

Marv, yes - the car does have Eco (engine stop/start) but I turn it off every time I get in the car.

There is no pressure loss. If there were there'd be either visual evidence (low brake fluid, puddles) or a gradually sinking pedal. While stopped the pedal does not gradually sink. It behaves as though I am removing my foot from the brake pedal - only I'm not. And it never happens if I engage Brake Hold.

I'll keep toying with it to see if there are any other conditions/factors in play.

Tbbt CLS

On my 13 CLS550, I don't have Eco stop/start (that's why I hunted for a low mileage 13) and the Hold feature is very hard to activate, so I don't use it. You really have to stomp on the pedal to get it to hold. My car holds fine at signals with light pressure on the brake. I'm wondering if you might have air in the system? Marv

ygmn

Does RPM spike up when car moves?

ss3964spd

Brake Hold is fairly easy to activate on mine, Marv, but was a bit harder on my 2011 E550. Air in the system would make for a mushy pedal, but I don't think it would cause the symptom I'm experiencing. Again, I'm at a complete stop with my foot on the brake, the car is stationary, and then they release.

No, ygmn, no change in RPM's.