Classic Mustangs (Tech) Technical discussions about the Mustangs of yester-year.

Braking "problem"

Old Oct 24, 2007 | 11:05 PM
  #1  
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Default Braking "problem"

I was speeding on a nice straight-away country roadearlier day when i noticed a deer aproaching the road. It was a good 10 feet away from the road but instinct kicked in and i braked hard. As i stomped on the brake, my car turned sideways but thankfully it turned out alright.

I cant seem to remember what it implies when your car pulls one way while brakeing. Maybe its nothing at all because it doesnt pull any which way while "normal" brakeing, just when i stomped on it earlier today. I have disks in the front and drums in the rear. My aligntment is good(had it aligned last month). Any ideas?

Thanks for any help.
-Hawkins
Old Oct 24, 2007 | 11:15 PM
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Default RE: Braking "problem"

Hawk....Did you lock up all 4 brakes?. If only the rears locked up and not the fronts, or the rears locked up before the fronts, then you need to adjust your proportioining valve so the fronts lock before the rears. When you panic stop and the rears lock, you've just lost control altogether and your going to go a'spinin.
Old Oct 24, 2007 | 11:17 PM
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Default RE: Braking "problem"

or the drums could be adjusted wrong, that can cause the car to pull in a certian direction when you brake hard. you shoud be able to feel that almost all of the time though.
Old Oct 24, 2007 | 11:28 PM
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ORIGINAL: Mustang Dad

Hawk....Did you lock up all 4 brakes?. If only the rears locked up and not the fronts, or the rears locked up before the fronts, then you need to adjust your proportioining valve so the fronts lock before the rears. When you panic stop and the rears lock, you've just lost control altogether and your going to go a'spinin.
I think you might of nailed that one on the nose. My eyes were on the deer, i dont remember much besides I was coming sideways down the road a good 20 feet. This proportioning valve, a quick outline of it, if you have the time would be nice.

Thanks,
Hawkins
Old Oct 24, 2007 | 11:31 PM
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Default RE: Braking "problem"

is your brakeing system stock? im not sure about '69s but '65s didnt have a proportioning valve stock. you could always add one though, theyre about $65 i think

are they drums all around or do you have disc front or what? if its all drums i would first start out by adjusting everything and see what that does for you.
Old Oct 24, 2007 | 11:41 PM
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ORIGINAL: Hawkins 812
I have disks in the front and drums in the rear. My aligntment is good(had it aligned last month). Any ideas?

Thanks for any help.
-Hawkins
Old Oct 24, 2007 | 11:56 PM
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Default RE: Braking "problem"

Basically, if a car brakes harder in the front, then the rear "is going faster then the front" as my auto teacher put it. The "faster moving part of the car will want to get ahead of the slower part"-this put it in dumb terms for us. So your fronts are probably doing more stopping then they should. A properly-tuned proportioning valve should fix the problem.
Old Oct 24, 2007 | 11:58 PM
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hahaha...oops

well in that case probably a proportioning valve would help if you dont already have one...if you do have one it would be located on the rear brake line, its a rectangular block of metal that has a **** on the top that you can "tighten" to get more pressure to the rear brakes or "losen" to get less pressure to the rear brakes. thats how mine works at least. im thinking you wont have one though...
Old Oct 25, 2007 | 12:02 AM
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Default RE: Braking "problem"

ORIGINAL: 350kmileFord

Basically, if a car brakes harder in the front, then the rear "is going faster then the front" as my auto teacher put it. The "faster moving part of the car will want to get ahead of the slower part"-this put it in dumb terms for us. So your fronts are probably doing more stopping then they should. A properly-tuned proportioning valve should fix the problem.
you know, the funny thing is usually when the rears lock up the vehicle whippes around, not when the front's lock up.
Old Oct 25, 2007 | 12:06 AM
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Default RE: Braking "problem"

Thanks alot for the help guys. Ill have to check that out tomorrow when i get back to the shop.

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