Brake Problems

blind655

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Ok here is my problem.. Sometimes when I go to stop or I make a sharp turn (like in to a parking space) my break pedal goes all the way to the floor and starts to pulse and i loose quite a bit of braking power, after a second or two it returns to normal. This doesn’t happen EVERY time I stop, I checked my brake fluid and its fine, and my ABS light is not on… Any ideas??

The vehicle is a Chevy suburban

Thanks
Mike
 

DougM

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Sounds like a brake line is being pinched when you turn? check the routing of the lines. I think there was technical service bulletin(TSB) about that on the 98-2001 Suburbabns.

Check it out and check with the Chevy dealer.
 

John Bitting

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Is your caliper hitting your lower arm?? Turn lock to lock and check it out.. I had problems with stock arms not many with the Cal Super Trucks arms..
 

Mikey

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Do you have a hydraboost on it? When that thing goes out no brakes or steering! My bros. '97 3/4ton ate them.
 

blind655

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Is it possible that there is air in the brake lines? My rear break lines were removed when I had my new rear end installed, maybe they didn't bleed all the air out..

Thanks
Mike
 

tkr

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Sounds like the ABS is engaging. What year is your Suburban?

Matt Nelson
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scott

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Sounds like theres Air in the lines.... My pedal did that once and thats what it was. Just re-bleed them.
 

tkr

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Air in the lines will not typically come and go, and will not give you a pulsing pedal. I'd suggest taking the truck out, and purposely trying to lock up the rear wheels to see if the pedal feeling is the same and what you're getting. A low, pulsating pedal with decreased braking is exactly what it feels like when the ABS engages.

Matt Nelson
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rdc

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I had what sounds like the same problem once apon a time. The bolt that held my limiting strap to the lower arm was hitting the caliper. I know John already said this but still check and see if that is the problem.

Eric
 

blind655

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Thanks for all the help... I'll check my arms in the morning to see if anything is hitting, and if nothings wrong I'll re bleed my brakes. I don't know why the ABS would engage, when I’m stopping its not a situation where the ABS should kick in. Maybe the ABS system is messed up. I'll look in to it.

Thanks again for all the info
later
mike
 

vwguy

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abs would kick in if you have a bad sensor

how ironic is it that most people slow down for speed bumps yet almost all of us here im sure pin it
 

tkr

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ABS engages when, under braking, it sees the two wheels moving and different speeds. Obviously it shouldn't be engaging when you're parking, but think about this. You're on the brake pedal, and you're turning sharply so the inside wheel is turning much less that the outside wheel. You could very well have a sensor problem making it too sensitive. I can understand a bolt hitting the caliper causing a pulsation, but how does that explain the low pedal and loss of braking? And I can see how air in the lines would give you a low pedal, but what about the pulsation and why on earth would it only happen when making sharp turns?

Matt Nelson
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John Bitting

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When the caliper(slider bolt)on the older chevys 98 down hits the lower control arm it spaces the pads aparts and causes the pedal to go to the floor on the first pump and then the pads reset and the second is back to normal.. It is pretty scary.. I speak from experience.
 

tkr

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that makes sense. I thought he was talking about a limiting strap bolt hitting the caliper....

Matt Nelson
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rdc

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I would second, (or third) that idea of your caliper hitting something...it happend to me. i think it pushes the brake pad when the caliper hits something, so when you step on the brakes it pushes the pad back out with out any resistance, and you have to pump the pedal...yeah? no?
Jaron
 

blind655

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Well i checked the arms and nothing is hitting... I looked at the brake lines and they are not pinched. I don't know!!! Would a having a locker in the rear cause break problems? Also I noticed when it happens a whirring (kinda like a pump) sound comes from the engine compartment, the side with the brake booster and ABS box....

Thanks
Mike
 

tkr

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You're ABS is engaging. Yes, a locker could definitely have an effect on it. What kind of locker do you have and what year is your sub?

Matt Nelson
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DPpatrol

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I agree that is an abs problem. Pulsating pedal and pumping noise is abs. The pulsating is caused by the abs system pressurising and depressuresing the system rapidly. The pumping noise is caused by the abs pump which does the pressurising/depressurising. I'd take in the truck in. Luckily most abs systems act indepently of the rest of the braking system so if the abs goes out you will still have brakes.

jason
 

Josh_Westwood

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Chevrolet has a known problem with this brake problem. I am not sure what they did to fix it. I have a suburban and have heard a lot of people talk about this happening to them. Do a search on yahoo and you should find some info on it.
 

blind655

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Well I think i made some progress today, I bled the brakes and the pedal feels better and haven’t had problems yet.. Matt, I have a Detroit Locker and it's a 1998 sub. I'll take a look around the internet and see if I can find any info on chevy brake problems.


Thanks everyone
Mike
 
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