My wife and I Jeep Wrangler as all of a sudden developed a nasty pull/twitch to the left at 30+ when you apply the brakes…when you apply the brakes It quickly twitches to the left but doesn’t continue to go that direction…. today I replaced the pads rotors and both calipers… the issue still exist.. checked all tie rods, control arm and track bar
bushings and everything checks out… had my fiancé move steering wheel back and forth and no movement in any suspension parts.. put a wrench on every bolt and everything is tight…. I’m at a lose at this point and looking for alittle help…
brake fluid has no issues with flow from bleeding brakes. Clean fluid flow until no air also

 

What about the condition of the rear brakes, rotors,calipers and pads. The jeeps have more bias to the rear brakes compared to many vehicles. They do a lot of the stopping power.

 

Check your front brake hoses. They tend to collapse internally and that will keep fluid in the calipers

 

Rear brake check out good… I lifted every wheel off the ground and all wheels spin freely also… part of the reason I’m so confused to what’s going on

 

Just seeing that wheels spin when raised is not adequate. That was the case when my Jeep pulled when first applying the brakes. A possible scenario is that the calipers are sticky, but not stuck. When you apply the brake pedal, not all caliper pistons initially move, allowing one wheel to see no braking power. Push the pedal harder, then they all move and no longer pull to one side.

 

There aren’t many details about your jeep or possible offroad use. Shot in the dark, but you haven’t pulled your rear hard brake lines down into a “V” have you? This can happen when offroading at times if the rear sway bar link bolt is sticking towards the frame too much. When the rear tire is stuffed the sway bar end travels up and on its way back down can at times grab that hard brake line and bend it into a “V”. A situation like that could lead to something like what Rob explained above where one caliper isn’t reacting as quickly due to a restriction. I’d think you’d notice that brake line quickly since it’s visually obvious, but just double-checking. This is what I’m referring to –

 

Might want to look at the ABS module as that provides bias for each brake. Maybe one is too much etc etc.