Rear disc drag

[Rt Jam]

Some is normal. Discs never spin as free as drum since there is no return springs to pull the pads back. You have a complete new rear axle assembly. Same, new bearings will not spin freely.

I thought you figured this out to be the mounting bolts rubbing the rotors?

 

[abbey castro]

Some is normal. Discs never spin as free as drum since there is no return springs to pull the pads back. You have a complete new rear axle assembly. Same, new bearings will not spin freely.

I thought you figured this out to be the mounting bolts rubbing the rotors?

Rear drums or disk will not free spin since they are tied through the axles to the differential.

 

[Baker7888]

Some is normal. Discs never spin as free as drum since there is no return springs to pull the pads back. You have a complete new rear axle assembly. Same, new bearings will not spin freely.

I thought you figured this out to be the mounting bolts rubbing the rotors?

The mounting bolts are extremely close to the rotor but they are not touching as seen with a light test. I am still going to grind them down I just haven’t had a chance yet.The pistons are sticking out of the calipers between a 16th and 1/8th of an inch of bare metal past the seal I think this is normal resting place but I don’t recall if they should retract more than that.???

 

[Rt Jam]

Pry the piston back so the caliper is floating. Clearance between pads and rotor. Still drags?

 

[Baker7888]

Pry the piston back so the caliper is floating. Clearance between pads and rotor. Still drags?

Ok i washed the bolt heads down earlier, haven’t reassembled yet.

When i push one piston in the opposite side pushes out… thoughts? (Pads touch either way - like they are too thick)

 

[Rt Jam]

The reaction is normal. When you push the piston back, it displaces brake fluid. It needs to go somewhere, in this case the fluid pushes the other piston back.
Either compress both pistons at the same time so the fluid goes back to the master or open a bleeder and let it come out.

I'm guessing you have not worked on many cars. Get a car guy to come over to help you. This is pretty basic stuff. It is also normal to have the rear of a rear wheel drive with discs to have drag. They will never freewheel. You are trying to turn axles and if you have a clutch style differential it's also turning other side or the driveshaft.

 

[Baker7888]

The reaction is normal. When you push the piston back, it displaces brake fluid. It needs to go somewhere, in this case the fluid pushes the other piston back.
Either compress both pistons at the same time so the fluid goes back to the master or open a bleeder and let it come out.

I'm guessing you have not worked on many cars. Get a car guy to come over to help you. This is pretty basic stuff. It is also normal to have the rear of a rear wheel drive with discs to have drag. They will never freewheel. You are trying to turn axles and if you have a clutch style differential it's also turning other side or the driveshaft.

Pry the piston back so the caliper is floating. Clearance between pads and rotor. Still drags?

Okay i realize that there will always be drag. The question was how much is normal. I know the wheels wont just free spin…there have been some minor issues with this kit, somewhat bizarre issues so the kit is obviously cheap quality…. i thought maybe this is a popular swap and someone on the board may have had similar issues..
As stated above the pads touch the rotors, meaning both inner and outer pad at rest, makes contact with the rotor, to which i cannot see how any amount of shimming, bleeding, removing flex hoses, or swapping out proportioning valves will fix. I expected pushing piston in would send fluid back to the master, so yes it was a surprise to me to see the opposite piston move. Bolts were “uncomfortably” close to the rotor which i will know if they are part of the problem tomorrow. After grinding all the zinc off i am now waiting for paint to dry. The kit instructions are generic but talk about pedal ratio, which nobody here mentioned. I honestly think the pads are too thick but again was looking to you guys or someone who has used these g body disc swap kits. Ive never had to compress two calipers at the same time, and my thought is after doing so and applying brake pedal i will be back at square one but it is not an issue and i will give it a shot tomorrow.