Braking with the engine off

[Wurlitzer]

2004 Accord, Manual Transmission

If I roll down my dirt-road, mountain driveway with the engine off, will braking without the booster on damage anything? Yes, of course the brakes become harder to engage but is any damage being done due to the increased pressure?

Don't tell me about safety concerns, just answer the question.

 

[kschachn]

Originally Posted by Wurlitzer
2004 Accord, Manual Transmission

If I roll down my dirt-road, mountain driveway with the engine off, will braking without the booster on damage anything? Yes, of course the brakes become harder to engage but is any damage being done due to the increased pressure?

Don't tell me about safety concerns, just answer the question.

Even though I might be able to answer it, maybe someone else will.

 

[Lolvoguy]

Increased wear and tear on your muscles and joints.
Not to mention possible firewall flex where the pedal mounts to it (yes, that's a thing...I just made it up).

 

[skyactiv]

I've done it a few times on stick cars with no ill effects.

 

[eljefino]

You have a reserve and will get 1-2 pumps of the pedal in with some power assist.

 

[Imp4]

Noparino... No damage to be had....

 

[CR94]

No damage, but why brake?

 

[atikovi]

You're stressing the seat recline mechanism. Better to use the hand brake instead.

 

[ecotourist]

Why would you do that? On my 2007 Accord with a manual transmission, when coasting down hill in gear with my foot off the throttle, the fuel shuts off (or so I understand), so I have power steering and power brakes and I'm not using any fuel.

 

[FordBroncoVWJeta]

Originally Posted by ecotourist
Why would you do that? On my 2007 Accord with a manual transmission, when coasting down hill in gear with my foot off the throttle, the fuel shuts off (or so I understand), so I have power steering and power brakes and I'm not using any fuel.

How is the engine still running without any fuel?

 

[ecotourist]

Originally Posted by FordBroncoVWJeta
Originally Posted by ecotourist
Why would you do that? On my 2007 Accord with a manual transmission, when coasting down hill in gear with my foot off the throttle, the fuel shuts off (or so I understand), so I have power steering and power brakes and I'm not using any fuel.

How is the engine still running without any fuel?

It's turning over (and at a good RPM) because of dynamic braking. You don't need fuel for that.

 

[ecotourist]

Originally Posted by ecotourist
Originally Posted by FordBroncoVWJeta
Originally Posted by ecotourist
Why would you do that? On my 2007 Accord with a manual transmission, when coasting down hill in gear with my foot off the throttle, the fuel shuts off (or so I understand), so I have power steering and power brakes and I'm not using any fuel.

How is the engine still running without any fuel?

It's turning over (and at a good RPM) because of dynamic braking. You don't need fuel for that.

You need a manual transmission (which the OP also has) of course.

 

[Skippy722]

Originally Posted by ecotourist
Originally Posted by FordBroncoVWJeta
Originally Posted by ecotourist
Why would you do that? On my 2007 Accord with a manual transmission, when coasting down hill in gear with my foot off the throttle, the fuel shuts off (or so I understand), so I have power steering and power brakes and I'm not using any fuel.

How is the engine still running without any fuel?

It's turning over (and at a good RPM) because of dynamic braking. You don't need fuel for that.


Automatics do it as well. Cars idle at 600-800rpm. Mine won't let the rpm go below 1,000 while coasting.

 

[Fawteen]

Originally Posted by Wurlitzer


Don't tell me about safety concerns, just answer the question.


It's a dumb idea from a safety standpoint.

 

[andyd]

I lost the roll pin that was the stop for the fast idle spring on my '66 Bug. Without the stop, the spring unwound and the idle cam jammed the throttle at 3/4 or so. 2AM 1/1 '73 in a freezing drizzle. I just wanted to get us home. I feathered the engine by shutting off the key to slow down. It worked better than sliding on locked brakes Kept it off until car started bucking . Turn key on until next brake event. A 15 mile drive I didn't use the brake pedal or throttle the entire way. To a certain extent, I could work the throttle through the cruise control on the 528e. to decelerate and accelerate . Fun on open road stuff

 

[E150GT]

I engine brake all the time in my car. I'm annoyed when driving the wife's car because it doesn't engine brake well. I have wondered though if all the engine braking I'm doing is causing increased oil consumption?

 

[The motor guy]

Originally Posted by Skippy722
Originally Posted by ecotourist
Originally Posted by FordBroncoVWJeta
Originally Posted by ecotourist
Why would you do that? On my 2007 Accord with a manual transmission, when coasting down hill in gear with my foot off the throttle, the fuel shuts off (or so I understand), so I have power steering and power brakes and I'm not using any fuel.

How is the engine still running without any fuel?

It's turning over (and at a good RPM) because of dynamic braking. You don't need fuel for that.


Automatics do it as well. Cars idle at 600-800rpm. Mine won't let the rpm go below 1,000 while coasting.



Mine does if I nail the brakes good from say 70 and go down to like 50 it will kick out of gear and be coasting in idle. Yes i'm talking about the truck in my signature. I think the torque converter just unlocks in that case to prevent damage to the transmission. Probably senses wheel slip or something.

 

[vavavroom]

Originally Posted by Wurlitzer
Don't tell me about safety concerns, just answer the question.


There's only one way to find out!

 

[JLTD]

Originally Posted by Wurlitzer
2004 Accord, Manual Transmission

If I roll down my dirt-road, mountain driveway with the engine off, will braking without the booster on damage anything? Yes, of course the brakes become harder to engage but is any damage being done due to the increased pressure?

Don't tell me about safety concerns, just answer the question.


No issues or damage. Only difference is that you won't have engine vacuum providing assistance, so pressure required on the brake pedal will be increased.

 

[supton]

Originally Posted by E150GT
I engine brake all the time in my car. I'm annoyed when driving the wife's car because it doesn't engine brake well. I have wondered though if all the engine braking I'm doing is causing increased oil consumption?

Might. It's high vacuum, so any bad rings or intake valve seals could leak oil. I think some engines use gas porting behind the rings so as to get better seal; and as such I could see those using yet more oil (but I think that tends to be high zoot engines). If consumption isn't bad, I'd ignore it, it's not like engine braking is going to cause excessive wear (high rpm yes but no load). If you do have high oil consumption, you could try a couple of tanks of fuel without engine braking and see if oil consumption drops. Then consider if the oil savings pays for shortened brake pad life.