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Old 25th August 2009, 15:31   #1
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Default Swift Half Clutch/Brake Issue

I have been observing a unique behavior in my swift. In traffic condition, when on Half Clutch [ Bite Point ], my brake appears to slip down 1-2 mm on its own.

Let me explain you the scenerio in more detail.

I am on half clutch, engine RPM is around 800, and my right foot is on brake. As soon as I slowly release the brake, the vehicle is ready to move and it moves correctly.

At static condition, at the same condition, when I press the clutch a bit, engine rpm rises to around 1100, and at this point the brake automatically moves down by 1-2mm. Mind you that my foot force is still the same. I was scared when it happened recently.

But when I was trying to understand the physics of the behavior, it eluded me.
Can anyone educate me on the same ? It is normal for the brake pedal to behave the way it does ?

Thanks and Regards
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Old 25th August 2009, 15:42   #2
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I am not sure about other behaviours but the engine RPM raising itself to 1100 RPM is something fishy better take it to service center and get her checked.
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Old 25th August 2009, 16:22   #3
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I have a Wagon-R and I face a similar situation but while the AC is on.

If I am standing at a signal holding the brake and the AC compressor turns off (with that click sound), the idling increases a bit now (since the AC comp is now off) and the brake pedal goes in a little more with no change in the pressure applied by my leg.

Seems like this is to do with hydraulics and the underlying set of operating functions while the car is running and is normal and nothing to worry about.

A hydraulic driven compressor for the AC (When the compressor is off) provides additional boost to the hydraulics of the brakes and moves them further in.

In your case, while the RPM increases to 1100 after holding the clutch, hydraulics function optimally at this speed of the engine and hence with the same pressure, the brake pedals sink in a little further.

Experts in the area can comment please as I might not be fully correct.

Last edited by paragsachania : 25th August 2009 at 16:34.
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Old 25th August 2009, 22:20   #4
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Quote:
Originally Posted by lambuhere1 View Post
I have been observing a unique behavior in my swift. In traffic condition, when on Half Clutch [ Bite Point ], my brake appears to slip down 1-2 mm on its own.

Let me explain you the scenerio in more detail.

I am on half clutch, engine RPM is around 800, and my right foot is on brake. As soon as I slowly release the brake, the vehicle is ready to move and it moves correctly.

At static condition, at the same condition, when I press the clutch a bit, engine rpm rises to around 1100, and at this point the brake automatically moves down by 1-2mm. Mind you that my foot force is still the same. I was scared when it happened recently.

But when I was trying to understand the physics of the behavior, it eluded me.
Can anyone educate me on the same ? It is normal for the brake pedal to behave the way it does ?

Thanks and Regards
Its normal. Because swift has power brake. Meaning, its master cylinder drum gets vaccum feed from engine.

PS: But don't ride the clutch. its bad driving.
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Old 26th August 2009, 00:55   #5
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Quote:
Originally Posted by SirAlec View Post
Its normal. Because swift has power brake. Meaning, its master cylinder drum gets vaccum feed from engine.

PS: But don't ride the clutch. its bad driving.
The above post about sums it up but, I would like to add one bit on the half-clutch or riding the clutch - never use half-clutch or ride with a foot on the clutch. You are literally frying your clutch when you do this.

Cheers,
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Old 26th August 2009, 09:33   #6
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Correct me if I am wrong. Generally dont we ride on half clutch in tight traffic situations ?
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Old 26th August 2009, 09:39   #7
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i agree. If you are stuck in traffic put the car in neutral, handbrake up and pull your foot off the clutch. at traffic lights, switch off the engine with the car in neutral, foot off the clutch and handbrake on.

half clutch, ,marginal revving and inching forward etc is a sure-shot way to spend big bucks on clutch assembly, facing and pressure plate. Never keep your foot on the clutch like most drivers do. worst thing possible.

also from complete halt, always use first to start moving - using 2nd etc is a very bad habit causing unnecessary strain on the poor car.

Quote:
Originally Posted by Ravveendrra View Post
The above post about sums it up but, I would like to add one bit on the half-clutch or riding the clutch - never use half-clutch or ride with a foot on the clutch. You are literally frying your clutch when you do this.

Cheers,
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