Mysterious Braking Boing?!?

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- snowfreckle
  
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posted
16 years ago

Wed, May 16, 2007 1:51 AM

hi volvo guys...i have a 1990 740 with a mysterious noise while braking. it sort of sounds like a boing, others think it sounds like a low note on an out of tune piano. it usually only happens when i am braking from a slow speed (parking, stop signs, etc.) i can feel a little difference in the brake, a little vibration, a little more give. there's also i squeaking from the front left wheel while i drive. my mechanic has replaced the brake pads, master cylinder, bushings, and hub over a period of 3 months. after the last visit it stopped for a month and then today came back. anyone have any idea what it could be? is it the calipers? is there a piano in my braking system? will i be crashing through stop lights? i'm also out of town and away from my mechanic. find someone to work on it now or wait a couple weeks until i'm back in town?

i'd appreciate any help!

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- Mal from Oz
  
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posted
16 years ago

Thu, May 17, 2007 6:12 AM

Had similar problem a few years back, not on a Volvo but on a '93 Magna - turned out to be the brake pedal return spring making the odd 'boing' when the brake pedal was depressed. If braking hard say from 30+mph it didnt happen - only when tootering along.

Went on for months driving me up the wall - went away on its own after a while.

Cheers Mal Oz

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- tom callaway
  
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posted
16 years ago

Fri, May 18, 2007 12:16 AM

I don't know if this applies to your 740, but many years ago, my 164 was making very similar noises just before the driver's side lower ball joint separated and dropped the suspension onto the pavement. It was making a creaking noise when steering and the boing when stopping. The creak was the dry ball joint and the boing was the spring shifting slightly due to the looseness in the suspension. I know that your car has a completely different suspension, but if it were me I would check ALL the suspension components NOW. It was no fun jacking it up and replacing the ball joint on the side of the road, and I'm just glad mine let go pulling away from a stop and not on the interstate

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- snowfreckle
  
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posted
16 years ago

Fri, May 18, 2007 1:11 AM

thanks for the posts so far!

...speaking of messed up suspension...last fall my front drivers side strut completely tore loose. it almost stabbed a hole through the hood before i got it to the mechanic. it's been eight months since then and the boing noise just began a month ago. but i wonder if that could have messed some things up that are just now voicing themselves. i'm just confused why it stopped for a month after i got the hub and bushings replaced and now is suddenly back.