[toinkee69]

i have a habit of putting the gear on neutral when stopped on a light. i've noticed that when i do that my brake pedal tends to sink in more and slowly. but when i leave it on drive it's more firm. i'm thinking my brakes need to be bleed coz of maybe air. i just want everyone's experience on this before i schedule an appointment for service at the dealership.

-jowell

 

[kjboyd]

get out of that habit!!! it's horrible wear on the transmission!

 

[Rich_Jenkins]

Possible. Never a bad idea to get your brake fluid flushed and bled.

Of course it could also be the brake booster providing a different vacuum pressure to the braking system under load of the transmission, and then not under load. :dunno:

 

[bjm442]

Of course it could also be the brake booster providing a different vacuum pressure to the braking system under load of the transmission, and then not under load. :dunno:

I'm thinking the same

 

[Supercourse]

i have a habit of putting the gear on neutral when stopped on a light. i've noticed that when i do that my brake pedal tends to sink in more and slowly. but when i leave it on drive it's more firm.

I think that is normal. The engine idle speed is a bit higher in N than in any other position including P as well as D, so vacuum varies.

Does the habit come from being brought up on a MT?

There is a safety side benefit - if your foot slips off the brake pedal onto the gas, you are not going to shoot out into the intersection.
(Maybe only applicable to drivers at high risk of heart attack or stroke?)

I don't see a need to get the brakes bled, but you should be coming up soon for your 2nd. brake fluid flush anyway (every two years).

 

[toinkee69]

yep, the habit stems from driving MT cars. i was thinking of the higher idle and vacuum to when the ride is on D & N. thanks for the input everyone.

 

[dharmadoggie]

All cars with AT do that. I figure it's firmer when in D because the brakes are working to keep the car stopped, and thus there is some back pressure on the pedal. I disagree that it has to do with idle speed or vacuum (but I am, ahem, an armchair expert). Look at your tach - it won't vary whether it is in gear or not. Idle is controlled by software these days.

I developed the same habit for AT cars that have rougher idle, like 4 or 5 cylinder engines. I have gotten out of the habit with the X3, although that was partly because I would release the brake and then try to shift to D, and the interlock wouldn't let me.