[Jim_N_Tonic]

"Also, I think I've used my parking brake once in the last year. What am I doing wrong??"

I was kind of thinking the same thing, I personally never use the parking brake. Even when I've had manuals, I just tossed it in reverse. But I suppose if you were in a hilly area and didn't trust your transmission park pin.

I didn't think about the hilly areas of These United States... Living in the oh-so flat state of Wisconsin, I rarely need to park on a hill, let alone use the e-brake to park. I do agree that it should be exercised occasionally to ensure it will work when needed...

Also, didn't know that the early Volts had a power release for the charge door....

The more you know.....

 

[El Dobro]

Also, didn't know that the early Volts had a power release for the charge door....

The more you know.....

Yep, on the 2011-2013, the plug button on the remote pops the charge door, on the 2014-15, it overrides delayed charging and allows you to charge immediately.

 

[hellsop]

Apologies in advance for the "powertrain 101" Poindexter lesson:

The parking pawl in the transmission, as in any [modern] passenger car auto transmission, locks the final drive. Meaning, a chunk of metal is forced into a gear that is positively continuous to the wheels, to prevent rotational movement. There is no torque converter connection. The torque converter is between the engine output and the transmission input. A torque converter is a fluid coupling. The Voltec powertrain has no torque converter. In vehicles with a torque converter, it is, essentially, a well lubricated bearing when the engine is off (and the reason you can't push/pull start an auto). The hydraulic fluid flow necessary to act upon the torque converter turbine is caused by the engine input to the transmission main fluid pump. The "rocking" you feel when P is engaged is no more than gear lash, torsional absorption, and tire cushion, all against the parking pawl.

All true, however the gear lash, torsional absorption, and tire cushion can conspire to bind up the pawl, causing it to be difficult to release in a way that even the Fine Manual warns about. The process that avoids this is also documented.

1) Come to a stop where you want to park. Leave car in "gear", foot on service brake.
2) Set parking brake.
3) Put selector in Park.
4) Release service brake.

You may not have a problem not using this process. You may not have a problem for years if you live in a nice flat place. But if you do use this process, you will not have a problem ever, and that's the goal of all kinds of neglected advice engineers give.

 

[Lug_Nut]

Apologies in advance for the "powertrain 101" Poindexter lesson:

The parking pawl in the transmission, as in any [modern] passenger car auto transmission, locks the final drive. Meaning, a chunk of metal is forced into a gear that is positively continuous to the wheels, to prevent rotational movement......
Keep in mind, P only locks the drive wheels, while the Parking brake locks the rear wheels. Using the P brake while parking on slippery surfaces or hills is advantageous. 4 wheel traction is better than 2.

DMM, the transmission "park' pawl locks the transmission output shaft, thereby locking the pinion and ring from rotational movement. It does NOT lock the axle shafts. Due to differential action one axle can rotate forward and the other backward with the transmission in park. Don't put the transmission in park and then jack up one drive wheel to change a flat.
p.s.: SAAB 99 from the 1970's had the parking brakes on the front, drive wheels.

The process that avoids this is also documented.

1) Come to a stop where you want to park. Leave car in "gear", foot on service brake.
2) Set parking brake.
3) Put selector in Park.
4) Release service brake.

Almost....
1) Come to a stop where you want to park. Leave your foot on the service brake. Put the selector in Neutral.
2) Set parking brake.
3) Release the service brake.
4) Put the selector in Park (reapply the service brake if that is needed for the Park-Neutral Position, "PNP" shift interlock).

The reason is to use neutral to unload the engine "creep" load sent through the transmission as "idle" so that there is no load, not even the low torque of idle rpm (or "creep" kW) on the pawl. It also confirms the parking brake is engaged preventing movement, not the transmission park pawl.

So does that make me a bigger nerd?
...not proud if it does, but not sorry for the corrections either.

 

[ddm2k]

DMM, the transmission "park' pawl locks the transmission output shaft, thereby locking the pinion and ring from rotational movement. It does NOT lock the axle shafts. Due to differential action one axle can rotate forward and the other backward with the transmission in park. Don't put the transmission in park and then jack up one drive wheel to change a flat.
p.s.: SAAB 99 from the 1970's had the parking brakes on the front, drive wheels.

Almost....
1) Come to a stop where you want to park. Leave your foot on the service brake. Put the selector in Neutral.
2) Set parking brake.
3) Release the service brake.
4) Put the selector in Park (reapply the service brake if that is needed for the Park-Neutral Position, "PNP" shift interlock).

The reason is to use neutral to unload the engine "creep" load sent through the transmission as "idle" so that there is no load, not even the low torque of idle rpm (or "creep" kW) on the pawl. It also confirms the parking brake is engaged preventing movement, not the transmission park pawl.

So does that make me a bigger nerd?
...not proud if it does, but not sorry for the corrections either.

We have transcended the practical argument defending parking brake usage to save the park pawl, and have entered this realm where we are arguing theory. More specifically, WHEN exactly is best to disengage the Drive gear when using the parking brake: before or after releasing the service brake?

While the idea of letting Drive push against the parking brake might sound like you’re doing something beneficial, such as “unloading the creep load” or “confirming your parking brake works”, it’s actually a VERY bad idea:

1. Your parking brake is not a service brake, do not “test” it with a traction motor load! It is a lighter duty assembly on only two wheels, meant to hold dead loads from rolling away. Period. End of story.

2.) Want proof? The Volt has, already, as part of its program, instructions to RELEASE the parking brake under excessive (read: traction motor) loads. Again: it is only for dead loads. If you want to test your parking brake, test it in Neutral on a hill. NEVER with drive forces behind it, even on flat ground.



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[Jimmer]

...So does that make me a bigger nerd?
...not proud if it does, but not sorry for the corrections either.

I think for the most part we're all nerds here.

 

[DMM1906]

I think for the most part we're all nerds here.

Ha! Yep...

 

[Lug_Nut]

I sent ddmk2 a PM and gave him (or her) a few days to reconsider his assertions and to allow him to modify his reply. He hasn't. I will.

1. Your parking brake is not a service brake, do not “test” it with a traction motor load! It is a lighter duty assembly on only two wheels, meant to hold dead loads from rolling away. Period. End of story.
2.) Want proof? The Volt has, already, as part of its program, instructions to RELEASE the parking brake under excessive (read: traction motor) loads. Again: it is only for dead loads. If you want to test your parking brake, test it in Neutral on a hill. NEVER with drive forces behind it, even on flat ground.

Please re-read my post. Nowhere do I advocate attempting to drive or to move the car with the parking brake set. The check for vehicle movement when the transmission is in neutral is to assure the parking brake is really set. The squeeze of the calipers and pads to sandwich the rotor is exactly the same whether the car is stopped, in park, in neutral, in drive, on a hill. The electric motors in the park brake actuators use the same current and voltage regardless of other conditions. If the brakes are really a "lighter duty assembly" that they might break when the transmission is in D or R, and the motor's "idle" motive force is fed to the drive wheels, then they are definitely not up to the exact same squeeze force when the car is parked on a hill.
The force of the rotation of the rotor between the pads, whether slowing, attempting to move, or when trying to not roll on a hill, is transferred laterally to the caliper carrier pins and is not transferred to (nor from) the axial squeeze of the caliper by the pads and park brake actuator.