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weird braking sometimes

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Old Jan 31, 2011 | 12:22 PM
  #1  
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weird braking sometimes

I was driving and my brake pedal started to get hard to push down and my stopping power was reduced ALOT. soon after my Trans (c6) started shifting very late. I assumed vac pump (idk just a hunch) and turns out the belt was loose or something and it wasn't spinning.
I tightened it, and shifting if alright again but still alittle off and the braking is still not perfect. Does the Vac pump affect brakes I know its whats causing my shift problems but i just want ot make sure there isnt something else wrong with the brakes. thanks in advance.
I'm going to fiddle with the pump i'm almost positive i know whats going on with it, so that shouldn't be a problem, I just having had time to play around yet
 
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Old Jan 31, 2011 | 12:43 PM
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Yes it does. It is what supplies the vac to the booster. With out vacumn your pedal will be hard as a rock and very little brake force.
 
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Old Jan 31, 2011 | 12:51 PM
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ha ok good thats exactly what I was hoping to hear.
I just need to play around with the alt and vac pump
does anyone know around what deflection (I think thats the term) the alt belt and vac belt should have for tightness
 
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Old Jan 31, 2011 | 12:51 PM
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Yeah, If your pump is bad your braking will be hard. The vacuum should be sending enough vacuum the the booster line to hold onto the end of you thumb without any support from below. If it falls off it might not be suppling enough vacuum. If you want to be totally sure - get a tester.
 
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Old Jan 31, 2011 | 02:00 PM
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ok Thanks i'll check that tonight or tomorrow, I have a spare so if it need replacing hopefully the other is up to par
 
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Old Jan 31, 2011 | 03:22 PM
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Since you mentioned the belt was loose, you probably have the right idea. Other things to check would be the vacuum tubing in case it developed a crack or leak someplace, also look at the vacuum reserve (the coffee can on the drivers side fender). If the pump checks out within spec, might be that the brake booster is leaking.
 
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Old Jan 31, 2011 | 03:47 PM
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Back in 2007, I was crossing the Rockies in Alberta Canada, and the vacuum pump belt broke......

That was not funny! I had to use both feet on the brake pedal to get that heavy box to slow down on those hills!


Sure did remind me of the importance of carring extra belts! Onces at the top of the other hill, there was a lookout, I stoped and installed my new spare belt.

The C6 wouldn't shift anymore, I had to manually shift it.
 
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Old Jan 31, 2011 | 03:57 PM
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I had my belt brake 2 summers ago, I think it went when I was pulling my car trailer with a Jetta up a decent hill. First time I had really revved the engine up (got close to, if not over 3,000 rpm). I didn't notice till the vacuum ran out a few turns later when I was pulling into my destination. I figure the belt was old and couldn't take the speed. Didn't have the spare so had to drive without for a short time until I could replace it, wasn't fun standing on the pedal to stop.

Funny thing was I couldn't find the remains of the belt anywhere. Several months to a year later I found it by the steering gear when investigating why it was leaking. Sure surprised me that it founds its way across the engine, and stayed there for so long.
 
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