Powerband

I am egregiously devoid of mechanical understanding in this matter: When waiting at the traffic light, is it better (for the engine/transmission) to activate the brake HOLD, or to put the vehicle into NEUTRAL?

Secondly, when activating the brake HOLD, the brake pedal has to be depressed a bit farther than the point at which the vehicle is held stationary. Is this correct? Call me old school, but will depressing the brake pedal so far stretch out something like a cable or deform some mechanical part?

Sorry for my mechanical illiteracy. Hope you can help. Thanks.

NYCGLK

You can push the brakes as hard as you want, it's a hydraulic system. You are just pushing the brake fluid in the lines and pads onto the rotors. That's what it's made for.

What exactly shifting in Neutral accomplishes? Brake hold is made just for that, applying brake while you move your foot from brake to gas on a hill.

Powerband

Thanks NYCGLK. Glad to hear depressing the brake pedal deeper is just a process of pushing a hydrolic mechanism. As for putting it in NEUTRAL, it eliminates the forward moment so the engine isn't loaded and I don't have to push on the brake pedal that hard. More so the engine doesn't feel so "bogged" down. Is this a needless concern, the engine bogging while holding the brakes? Thus the inquiry of which is better, brake HOLD or NEUTRAL?

Thanks again for your insight, something I'm severely missing.

NYCGLK

Your transmission adapts to your driving style and reacts to how you apply throttle. I think it's smart enough to handle sitting at stop light without your intervention.

Powerband

Which imparts LESS mechanical stress: Brake HOLD, or sitting in neutral?

NYCGLK

I highly doubt there is a meaningful difference, that's what torque converter is for. Probably shifting between D and N produces the most stress to engage/disengage the transmission.

You are thnking into this way too much. If your tranny or engine fails, it won't due to sitting at a traffic light. It will be due to a defective bearing or messed up electronics.

Powerband

Thanks again, NYCGLK, I appreciate your replies. Perhaps I'm thinking too much into this, but I wouldn't be the only one. Here's what technical editor for TopGear has to say about putting the vehicle into neutral while stopped in traffic.

http://www.topgear.com.ph/features/c...uck-in-traffic

It seems a polarizing topic.

LesF

I use the hold feature most of the time with neutral saved for things like draw bridges where the wait can be more than a couple of minutes and I still want a/c and I don't want the car to move forward if I touch the throttle. The brake hold in traffic can be automatic if I'm in Distronic Cruise Control mode. One touch to the cruise stick and hold releases until the next stop if it's caused by slower traffic then the auto brake and hold again apply.

NYCGLK

What a non-sense article! Does this guy even know how automatic transmission work? Wear out clutches? Heat your brakes? Have higher maintenance cost? What the F is he talking about.

Diabolis

NYCGLK is 100% correct. That article is complete nonsense. You are putting a lot more stress on the transmission by shifting in and out of neutrual. Hold the vehicle with the brake and leave it in D.

As for the brake HOLD feature, you activate it by a double-press on the brake pedal, not by pressing harder. All you'll do by pushing down too hard on the pedal is wear out your brake booster prematurely or burst your master cylinder.

Powerband

Gentlemen, thanks for your comments. I think I'll stick with the purpose-designed brake HOLD.

As for the double-pump: the manual simply instructs pushing the pedal quickly and further down until the HOLD light illuminates on the instrument cluster. Also, this Mercedes Benz video shows the same procedure:

http://www.mbusa.com/mercedes/owners...007c184335RCRD

Will you please let me know if I'm missing something?

Thanks again.

Diabolis

Well, the brake HOLD feature is really only useful if you want to rest your right leg while you're waiting at a long red light.


As for the double-tap, that's another way of engaging it (partially release the brake pedal and reapply). The "press harder" does not always work on a C63 for example as you may be aready pressing very hard to scrub off speed, and the pedal feel is a lot firmer near the end of the travel so you can properly modulate it. The MB instructions and video are certainly the "approved" method of engaging it on the GLK.

Powerband

Actually, after your initial comment about the double-pump, I experimented with that technique. You are correct. On my drive home I double-pump about a dozen times and paid attention to the details of what activates the brake HOLD.

It turns out that the more rapidly the brake pedal gets depressed, the sooner the HOLD activates. The double-tap isn't necessary, but it comes into play if you don't want to depress the pedal PAST the point required to stop the vehicle. This means, after braking to a complete stop, let up on the pedal partially and then rapidly "tap" it down again. This way, the brake HOLD activates without pushing the pedal down so darn far, as demonstrated in the Mercedes Benz video (in the link above).

Had you never mentioned the double-tap, Diabolis, I would have never experimented and instead adopted the technique suggested by the owner's manual and video. The double-tap is far more gentle and easy to activate the HOLD feature, requiring far less pedal travel.

Hope this assists someone in the future.

Thanks again.

NYCGLK

Speaking of double tapping...if you double tap the GAS pedal it'll downshift and hold in lower gear for a bit, the tranny thinks you are in an uncertain situation and may need extra power to get out of trouble.

Diabolis

Thnak you for explaining it a lot better than I ever could!