Coasting in neutral, brakes failing

master.axu · Jun 19, 2008, 06:43 PM

I know lots of people are doing this to save gas, coasting in neutral.

I was doing it today and I had to brake, I hit the brake pedal but the car didn't seems to slow down, I would say it took twice the normal distance to stop. It felt like my brake rotors were oiled or something, it just didn't stop as I was used to.

Now I'm wondering if this was due to the engine being at low RPMs because of neutral, or something else? This was also after the car stayed in the sun for 8.5 hours, so that might have affected too.

It did that only one time, the first time I hit the brake after leaving the parking lot.

The pedal travel was also longer than normal. I checked the brake fluid level and is OK. What could it be?

brian95638 · Jun 19, 2008, 07:10 PM

i heard coasting on neutral causes mroe stress on brakes because when ur in gear.. ur engine helps stop the car soo u use less brakes to stop car.
also when you pop ur car back in gear w/ an auto i heard it can damage ur tranny somehow.. not sure how but yeah.. better to spend a few more bucks on gas than to replace ur tranny

mezzedupdream · Jun 19, 2008, 08:47 PM

I do this all the time but I have m/t. When ever I'm going to come to a stop I go in neutral and brake until I stop or when I'm coming to a turn I go into neutral and at the corner shift to 2nd or whatever. None of this do i do in an unsafe matter. I haven't felt any affect on my brakes but I'm sure there is. I thought doing this was normal. I never stay in gear when breaking.

Bawb3 · Jun 19, 2008, 09:24 PM

Down shifting does help the car slow down without using as much brake power. As well for a CVT if you have the sport mode, cant remember if the ES's have it.

What caused that to happen? I have no idea, could have been the heat from sitting in the sun temporarily messed with the brake pressure(A long shot) or something, or it could've been your imagination because you're used to braking in gear.

If it didn't happen again, and it hasn't yet, then I wouldn't worry about it, but if it happens again and more frequently then I would definitely take it in to the dealer before you get yourself into a wreck.

Quote:

when you pop ur car back in gear w/ an auto i heard it can damage ur tranny somehow..

This is true, but only if you tromp on the gas or rev it up fairly high and then drop it into drive. I really don't know how a CVT would respond to that treatment, because they are not like regular automatics, but I am sure it wouldn't be good for it. If you're just coasting in Neutral it shouldn't hurt anything.

psxnitro · Jun 20, 2008, 01:09 AM

I always go into neutral on my CVT when I'm coasting, and almost always when I'm about to go into a stop sign or red light.

CVT seems to have no problem adjusting, cause I know my friend tried this on his auto matrix, and pretty much almost red lined his car when he put it back in drive. I think it was due to auto going to first gear from neutral.

evo_soul · Jun 20, 2008, 07:02 AM

An Automatic Transmission CVT include, has more sensors that I can count that work to prevent damage from neutral to gear shifting. even if you did not apply gas, the ECU or related sub system will apply throttle or gas to match the speed, load, etc. to ensure proper engagement between the engine and the transmission via the TQ converter. I am not saying its impossible to damage your transmission but its pretty hard.

As for coasting in neutral, I wouldnt do it. you can do the same thing better managing your driving habits. Personally as soon as I see a light change, regardless of how far, I always take my foot off the pedal. things like that. Also, as was mentioned early, not using engine breaking, will result in faster wear on your braking system

ipv · Jun 20, 2008, 10:29 AM

I don't think being in neutral has anything to do with the break problem.

Think about it, if the break don't work in neutral, how can the mechanic in the shop test the break at all.

nunyas · Jun 20, 2008, 10:46 AM

eh... you have a torque converter on your transmission. If you're in "D", shifting into neutral for slowing/stopping is pointless, because the engine isn't spinning enough RPMs to make the torque converter "engage" (i.e. it's like pushing the clutch in on a manual to coast). Even IF you feel the effects of engine braking while in "D", you'll save more gas by leaving it in "D", because modern engines and ECUs are programmed to use less fuel while engine braking than sitting at idle. Some people claim that modern engines use no fuel while engine breaking, but I have a hard time buying that claim.

mitsuatb · Jun 20, 2008, 10:59 AM

That should not happen, have your dealer check the Vaccum Booster on the master cylinder.

If the line is damaged, or the check valve is leaking you will loose the assist that you normally have.

In gear / out of gear brakes should be almost the same, but if you have lost the assist, then the brakes won't feel right

Happens to alot of cars with big cams, but that is not your problem.

Mitsuatb

Quote:

Originally Posted by master.axu

I know lots of people are doing this to save gas, coasting in neutral.

I was doing it today and I had to brake, I hit the brake pedal but the car didn't seems to slow down, I would say it took twice the normal distance to stop. It felt like my brake rotors were oiled or something, it just didn't stop as I was used to.

Now I'm wondering if this was due to the engine being at low RPMs because of neutral, or something else? This was also after the car stayed in the sun for 8.5 hours, so that might have affected too.

It did that only one time, the first time I hit the brake after leaving the parking lot.

The pedal travel was also longer than normal. I checked the brake fluid level and is OK. What could it be?

Kurt · Jun 20, 2008, 11:15 AM

Quote:

Originally Posted by master.axu

I know lots of people are doing this to save gas, coasting in neutral.

I was doing it today and I had to brake, I hit the brake pedal but the car didn't seems to slow down, I would say it took twice the normal distance to stop. It felt like my brake rotors were oiled or something, it just didn't stop as I was used to.

Now I'm wondering if this was due to the engine being at low RPMs because of neutral, or something else? This was also after the car stayed in the sun for 8.5 hours, so that might have affected too.

It did that only one time, the first time I hit the brake after leaving the parking lot.

The pedal travel was also longer than normal. I checked the brake fluid level and is OK. What could it be?

If it worries you that much, have your brakes looked at. I have never noticed my brakes working any worse in neutral compared to using them while the car is in gear.

This isn't related to your brakes, but read this thread. It is discussed why coasting in neutral uses more gas then coasting in gear.

nunyas · Jun 20, 2008, 11:25 AM

loss of vacuum assist will result in the pedal effort taking a LOT more muscle to haul the car in.

Excessive travel is usually because there is a fluid leak somewhere, or because the pads have "drifted" away from the rotors. Sometimes some of the fluid can go back into the MC from the brake lines due to extreme temperature changes. IF the fluid gets hot, it'll expand. When it cools, it'll compress and take up less volume in your lines and as a result pull the pads away from the rotors. So, the first use after this cooling cycle the pedal will travel more than normal. "Normal temp changes" during the day shouldn't make a noticeable change in pedal travel, unless you live some place weird where it goes from 115 during the day to 50 or 40 at night.

Personally, I would just pay more attention to it over the next day or so. If it doesn't happen again, I wouldn't worry about it. If it DOES happen again, I'd pay more attention to how I drove the car before letting sit over night. Oh yeah, and make sure you aren't driving around with your parking brake on...........

master.axu · Jun 20, 2008, 05:20 PM

Thank you all for your answers.

I forgot to mention that it happened after a two week period of not driving the Lancer. I had switched cars with my wife, so I drove a civic for two weeks and then went back to my Lancer. Maybe that's reason it felt like that, cause the civic has much crisper brakes and I got used to that.

Now it feels right, even after staying in the sun and braking in neutral.

10x

phalenCAN · Jun 21, 2008, 11:39 PM

but if you stay in gear while coming to a stop you will save on gas. When you shift into neutral your engine has to burn gas to keep running...

LS1CRAZY01 · Jun 22, 2008, 08:59 PM

The reason your brakes feel different is because your trans does aid to braking by down shifting. Just like when your in a manual transmission car. In my Trans AM its a night and day difference in braking distance when I down shift it rather then putting it in neutral and coasting. My TA is a 6 speed manual by the way. Havent tried to put the Lancer in neutral yet and stop. I personally think it will cause more wear on your trans. Pay attention to your tach when your doing this and you will notice when you put it in drive from neutral your tach jumps a couple hundred rpm. The reason it is happening is so that the speed of the motor can match the speed of the trans. In a manual car you can rev match so the engine and trans can engage at the proper rpm. DONT TRY THIS WITH YOUR CVT THOUGH!

psxnitro · Jun 23, 2008, 02:45 AM

Quote:

Originally Posted by LS1CRAZY01

The reason your brakes feel different is because your trans does aid to braking by down shifting. Just like when your in a manual transmission car. In my Trans AM its a night and day difference in braking distance when I down shift it rather then putting it in neutral and coasting. My TA is a 6 speed manual by the way. Havent tried to put the Lancer in neutral yet and stop. I personally think it will cause more wear on your trans. Pay attention to your tach when your doing this and you will notice when you put it in drive from neutral your tach jumps a couple hundred rpm. The reason it is happening is so that the speed of the motor can match the speed of the trans. In a manual car you can rev match so the engine and trans can engage at the proper rpm. DONT TRY THIS WITH YOUR CVT THOUGH!

I've actually put my car on Neutral by mistake a couple of times while going 80mph, mostly because I thought I was in sport mode... The RPM drops to 500, the usually just goes back to around 2500 without a big spike when I return it to D mode, unless you were stepping on the gas of course... I think the CVT is a pretty durable transmission.