| [ Total Views: 494 | Total Replies: 3 | Thread Id: 13618 ] |
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ash logan
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| posted on September 22nd, 2003 at 04:46 PM |
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need help with a brake problem
I suspect a master cylinder problem.
#1
The brake pedal is very soft often after it has been sitting overnight. The pedal will go straight to the floor with only a small amount of
resistance. When the brakes are at this stage they will slow the car from 50km/h in a minimum of 15 seconds. After driving for about 2 mins (in which
time i would have negotiated about 6 suburban right angled corners) the pedal feel and brake function come back to normal.
#2
In addition to the above problem the brake pedal often becomes extremely hard with a maximum of 4cm travel. When the brakes are like this it feels as
if i am driving with the hand brake on. The brakes usually get to this stage after sitting at traffic lights for longer than about 30 seconds and when
i am slowing down gradually. Multiple stops exacerbate this problem. When this situation occurs a build up of dust from the brake pads is noticed,
along with a very strong smell.
It seems to me that the problem is caused by not enough heat in the first case (#1) and excessive heat in the second case (#2).
Could it be that the brake fluid is getting to hot (therefore expanding or maybe boiling) and pushing the pads against the discs?
I realise that this is a long and boring post but any help is greatly appreciated.
[Edited on 22-9-2003 by ash logan]
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PurpleT3
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| posted on September 22nd, 2003 at 07:47 PM |
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Sorry Ash, cann't completely answer your question. It seems unlikely that your brake fluid is boiling, this usually only happens if you are
racing or using the brakes heavily such as driving down a long steep hill. Temperature shouldn't effect brake performance to this extent.
What does it smell like? Do you notice the build up of brake dust while you are driving or once you are home? Have you looked at the calipers/drums?
Any fluid leaks?
Ain't nothin' like the wind in your hair.
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ash logan
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| posted on September 22nd, 2003 at 10:30 PM |
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My father has done a little tinkering tonight, as it is his car. I will give a pogress report after driving it.
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geodon
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| posted on September 23rd, 2003 at 08:28 AM |
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Start by bleeding & adjusting the brakes & assess the situation then. Has any work been done?
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koolkarmakombi
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| posted on September 23rd, 2003 at 08:59 AM |
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You dont say what sort of car it is.
My money is on a duff master cylinder.
Cheap to replace. Dont bother rebuilding the old one.
If it is a kombi the booster could be dodgy too. Often it is a bit of this, and some of that on these older cars.
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Ray65432
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| posted on September 27th, 2003 at 11:25 AM |
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kombi (i think ) brakes
the hard pedal could be caused by a faulty booster or fluid not returning to master cyl causing brakes to stay partly on . do the brake disks get
hot when this happens ? the low pedal could be caused by fluid leaking past the primary m/cyl cup. sit in the seat stationary with light to
medium pressure on brake pedal & pedal may slowly sink to the floor if primary cup is leaking anyway i would replace M/cyl before it lets u down
completley also change brake fluid in whole system ( every 2 years ) if this does not cure all your problems have your booster re built
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