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2012 Forester Manual
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73 Posts
Discussion Starter · #1 ·
So a few weeks ago I replaced my front calipers, rotors, and pads.
The front calipers were seized and were causing a horrible vibration at high speed stops

Any-who, the car feels great now, brakes like a dream

The only thing that changed is when I get in the car to start it up after sitting overnight and press the brake (Yes I know I dont have to with it being a manual, it just seems safer),
the pedal seems unusually high and super hard, like stepping on a brick.
Once I start the car it drops down to normal position and everything feels fine with the engine running.

Also if I am running errands and am in and out of the car frequently the pedal does not do this in between startups. Its only after letting it sit overnight.

Anyone have any input?
 

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2021 Forester Limited
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260 Posts
It's because once started, the engine vacuum kicks in the power assist and "adjusts" the pedal height/feel where it is under normal operation. The higher pedal with it off is probably because you got used to it being lower with the worn/defective brake parts.

In between stops, there is enough vacuum stored to keep it at the engine running height/feel..

The hard as a brick feel is what the brakes will be like if the engine stalls, and you push the pedal too many times. Or the booster fails. The car will stop, but it will take considerable more effort and distance.

Bottom line, it is 100% normal.
 

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Registered
2012 Forester Manual
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73 Posts
Discussion Starter · #3 ·
It's because once started, the engine vacuum kicks in the power assist and "adjusts" the pedal height/feel where it is under normal operation. The higher pedal with it off is probably because you got used to it being lower with the worn/defective brake parts.

In between stops, there is enough vacuum stored to keep it at the engine running height/feel..

The hard as a brick feel is what the brakes will be like if the engine stalls, and you push the pedal too many times. Or the booster fails. The car will stop, but it will take considerable more effort and distance.

Bottom line, it is 100% normal.
Thanks for the reply!
 

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2018 Forester XT Limited CVT
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1,006 Posts
I don't know when automatic transmission cars started disabling the starter when the brake pedal isn't pressed (our family had been driving manuals for the last few decades), but I suspect that you have to press the pedal hard enough to light up the brake lights, and that's it. A very light press. I have wanted to test this on my CVT equipped Forester but keep forgetting.

So, is it actually safer to have the brake pedal pressed during starting? If you have to press it only enough to light up the brake lights, then it's not safer because there's no braking happening. If you're not able to apply as much braking pressure using your foot, without the power assist, it's only a little safer. If it's to keep your foot off the throttle pedal during starting, today's cars have electronic throttle and throttle input is ignored during starting, so it's not safer. Is it just safety theatre and not real safety?
 

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2021 Forester Limited
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260 Posts
Power assist is partially there because cranking creates vacuum. My MTX neon drops the brake pedal as soon as it begins cranking. I generally don't push the brake pedal, as the clutch has the interlock.

Having your foot on the brake means it's already there if something does go wrong. You don't have that half second or so to get your foot on the brake. If the person should panic, they might hit the gas instead of the brake.

And the throttle input is not totally ignored on most vehicles during cranking. Putting the pedal to the floor on a lot of fuel injected cars turns off the injectors. This is to clear out a fuel flooded cylinder. Commonly known as "Clear Flood Mode".

Nothing is 100% foolproof all of the time, but being prepared/in the habit is generally a good idea. Doing it without thinking of it already has you a step ahead.
 

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2018 Forester XT Limited CVT
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1,006 Posts
Interlocks are a good thing, but how many redundant interlocks do we need? The car can already check: 1) Clutch disengaged. 2) For CVT, is the transmission in N or P. 3) Is the parking brake engaged. 4) Is the RPM zero. 5) Is the tire speed zero. Are we going to add checks for: Is there a bum in the driver's seat. Are the doors and hatch closed. Are the headlights on. Is the hood closed. For US vehicles, are the tire pressures okay.

Many years ago I started a Mustang and wasn't paying attention and the car lurched forward. The parking brake limited the amount of forward movement. This car apparently did not have the clutch interlock. And it apparently did not check to see whether or not the transmission was out of gear. I guess if they make sure the transmission is out of gear, that could have some ramifications for push starting the car. (Not going to think through that right now.)

The clutch interlock for my 2007 Forester failed, and it was a pain in the donkey to start the car. The car was fairly new, a year or two old. And they had to get the part from Toronto so I had to screw around and take 10 minutes to start the car for almost a week. So interlocks can become a nuisance (ever have an alarm problem?). In my 2018 I once opened the back hatch so I could see my trailer as I was reversing. First of all, it wouldn't even open the hatch unless the doors were unlocked and the transmission was in P. Then, it complained SO MUCH about the hatch being open and the car being in motion that it made me want to stop reversing. If I had been locked out from reversing, due to safety interlocks, I would have had to reverse while not being able to see the trailer, and that would have been MORE dangerous.

I don't know which of these interlocks are mandated and which were just put in as "features." But they can overdo it in some areas, and slack off in other areas. For example, in the US, they still allow new cars to blink the brake light/tail light as a signal, instead of using a separate yellow turn signal. And in the front, they still allow new cars to turn off a marker light and use the signal in its place. And these things are for cosmetics, and they give up some safety for it. Stats from somewhere, I forget where, maybe the SAE, show that separate yellow turn signals cut down on accidents.

Oh here we go. Lots of nuisance interlocks, but they allow trading safety for cosmetics.

 
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