[scld1354]

I recently noticed the front end shakes pretty bad when braking hard, and I'm pretty sure it only happens when the brakes are "cold".

Im usually pretty good about allowing enough space in front of me so I never really have to brake really hard. But there is one corner on my way down the hill that I have to slow down pretty quick.

The brakes don't shake under normal driving, so I'm pretty sure it's not rotor run out. When I get a chance, Ill put a dial indicator on there to make sure.

Any ideas?

 

[TravisITGuy]

sounds to me like either your front ball joints are worn out and need replaced or your rotors are warped.

 

[mtnhead]

Possibly warped rotors.

 

[scld1354]

If it were warped rotors, wouldnt the brakes shake all the time, or at least every time I used the brakes? Becasue they dont...

Ball joints were just replaced with Spicer ones.

 

[Smok3y]

Where is the shake at? Is it in the steering wheel, under your ass, or in your back?

If it's in the steering wheel, its balljoints, rotors, pads, or tie rod ends. Also could be poor alignment.

If it's under your ass, and nothing in the wheel other than what you are feeling already elsewhere, it's most likely a driveline issue.

If it's in your back, it's usually a problem from the rear end somewhere (usually accompanied by a slight whoopty feeling under your buttcheeks also, but ever so slight)

Also if you lifted (which I don't see any note of) I would drop the sway bar. You can sometimes get a shimmy from that if its offset due to the lift.

 

[scld1354]

Im not lifted. It feels like the shake is under my feet. If it makes sense, it fees like everything shakes except the steering wheel.

 

[broncosaurus rex]

Gotta be Rotors ... Possibly not warped bad enough under normal braking but noticeable under hard

 

[Gacknar]

What brand and how old are the tires?

 

[TheUnforgiven]

rotors can shake the vehicle, and the pedal, but not the steering wheel. sometimes they'll shake the wheel, but not the pedal, catch my drift?

although in my experience with rotors that only pulsate intermittently, they will pulsate more when hot than cold. My car has a slight pulsation if i use the brakes hard and get them hot, but it goes away once they cool off.

Check your radius arm bushings too!

 

[scld1354]

Gotta be Rotors ... Possibly not warped bad enough under normal braking but noticeable under hard

Ill get the dial indicator out tonight and check for run out. What is an acceptable number?

What brand and how old are the tires?

They are Costco brand tires (Kirkland). I don't know how old they are, but they look good. There are no cracks and plenty of tread left.

although in my experience with rotors that only pulsate intermittently, they will pulsate more when hot than cold. My car has a slight pulsation if i use the brakes hard and get them hot, but it goes away once they cool off.

Check your radius arm bushings too!

Ill check run out today. I only feel shaking the first couple of times I really get on the brakes first thing in the morning. It goes away after everything "warms up". I dont think I get the same thing when I leave work. I'll check today. Radius arm bushings were replaced by PO and they look to be in great shape.

 

[TheUnforgiven]

thinking back hard to my days at a chevy dealer (we had to dial indicate rotors that were cut under warranty), i think the ''acceptable" spec by GM was less than .005''. The consensus around the shop is you aren't going to feel anything until it gets above .015''

 

[Bruno2]

Originally Posted by Gacknar
What brand and how old are the tires?

They are Costco brand tires (Kirkland). I don't know how old they are, but they look good. There are no cracks and plenty of tread left.

They could be seperating. That was my first thought. Possibly severly out of balance. Look and see if you lost a wheel weight. Cheap tires are usually harder to balance. I have bought tires from Sam's Club before. Their techs dont really know how to mount tires properly let alone balance them right.

Sounds more steering or chasis related . If you have a buddy that is savvy you guys could take turns shaking the truck with the steering wheel while the other one looks at all the steering and chasis components. Then maybe even jack it up and give it the ol front end inspection.

 

[seth15c]

I'm curious if this person found a fix as my bronco is acting similar to this post.

My Bronco is shaking sporadically from the front right side when braking. It seems to only shake when I break soft. If I stomp the brakes, it usually doesn't shake. Also, the shaking comes and goes. 80% of the time it breaks smooth with absolutely no shaking. And then at other times I will brake, and the truck will shake violently. It has new tie rods, ball joints, and calipers. Also, the Ford dealership said the rotors were fine and they also were the ones that replaced the caliper thinking it was that sticking. Still no fix. Any help on this issue would be great.