mattyboi

I had a seized piston in one of my front calipers so I through in new seals. I was expecting to be able to freely spin the wheel while tires are off the ground but there's still a bit of drag going on.I can easily move it with 2 hands though. I'm not sure if it's the pistons holding it up again or it is the cv axle/driveline causing the drag? Or is this by design? Bearings have already been inspected and repacked with fresh grease. It's 1990 ifs 4runner 22re.

RAD4Runner

I think some drag is normal. Maybe different from rears where the brake shoes have strong return spring to pull them away from the drum. Your CV should not be in the equation IF your hubs are in free/unlock position.

PLEASE share how your caliper rebuild experience was. (My truck pulls to the left when I brake so I plan to check the calipers out soon.)
Was it tricky?
What condition were the caliper walls when you did it? No rust? If rusted and you had to hone, did you have to buy seal for oversized caliper bore?
TIA.

mattyboi

The pistons had some rust that was removable with scotchbrite pads. But a couple of them were pitted pretty badly. I'm hoping it won't wear out the seals and cause leaking down the line.
The walls were surprisingly rust free though.

As for the process, with shop air it was pretty easy to shoot out the pistons one by one. My friend has a huge air compressor but with no air I have no idea how you can get them out. I heard of some guys pumping the caliper full of grease until the pistons pop out, but it'll take forever to clean up that much grease.

Also my 4wd is add. So I don't believe the wheel free spins. Isn't it still spinning the CV axles and front dif when moving in 2wd?

wyoming9

iTrader: (1)

There is drag from the bearings

The pads drag slightly

Then like you thought the CV axles are spinning .

This all adds up.

Now if you need to really fight to turn the wheel you might have some issues .

This is Hydraulics if your pistons are at all rough to the touch being able to feel anything dragging a finger nail over the surface is not good .

scope103

There shouldn't be much perceptible drag from the bearings (and the half-shafts shouldn't contribute too much), but the brake pads are "designed" to drag a little. As RAD4runner points out, drum brakes have a return spring to pull the shoes off the drums, but disc brakes pull up close to the discs and stay there. If you were concerned enough to post here, it wouldn't be much effort to lift off the calipers and see if that takes the drag with them. Then you've eliminated a driveline issue, and you can rest easy.

As for RAD4runners pulling to one side, I had that happen on a truck when the flex line to the caliper failed internally and blocked. That brake really wasn't applying at all. I "discovered" it when replacing the pads and found I couldn't push the piston back into the bore -- the hose was blocked in both directions.