This is a crazy problem with my 2003 F-150 only when I use my parking brake. When I release my parking brake, it feels like the left side of the truck drops a couple of inches, it does this all the time, even when its parked level or on a hill, I can't figure out why its doing that. Any Ideas?

 

I can understand why both sides would do that on a hill, but on level ground? And only the left side? That is very strange.

Jack it up and apply the parking brake one click at a time, checking the drag on each wheel. Sounds like only one side is grabbing. Are either of the calipers holding pressure after the pedal is released? Either piston sticking?

SL

 

its still under warranty, im going to call the dealer on Monday. its only the left side, i jacked it up and worked the parking brake, and the wheels move free, no loose suppession, no broken springs, i was just seeing if someone else had the same problem. Its driving me crazy what it is.

 

isnt the parking break only on the left side?

 

Parking brake cable splits and goes to both left and right on my truck (see signature). Pretty sure that's standard.

 

I was thinking about this last night.
Try follow my logic here. It may be a lenghtly explanation.

Looking at the rear axle from the drivers (left) side.

As you pull up to park and you apply the brakes the rolling forces (inertia) causes the rear axle to twist counter clockwise. Rasing the rear of the truck.
As you stop most, but not all, of the twist is released.
You throw it into park, set the parking brake, but the chassis and springs are still loaded with that bit of counter clockwise twist. Being held buy the brakes and transmission.
Now, you jump back in, fire it up, release the brake, drop it in gear and now the engine torque twists the rear end clockwise. Which causes the rear of the truck to drop a couple inches.

If you have any understanding of how engine torque and braking forces act on rear suspensions you'll see what I'm saying.

 

Iggy, I do see what you're saying. That's why I usually allow the vehicle to settle into "Park" before applying the parking brake. But this would still not explain why only the left side rises and drops, unless the right (passenger's) side parking brake is broken or needs adjusting.

Jeff

 

I can't imagine why on a solid axle you would only feel movement on one side.
It would take an independant rear suspension for a single parking brake to effect the truck.

I'll have to think about it some more. If I come up with anything I'll let you know.