Piston blew out of caliber during a brake rotor and pad replacement.

Let me start by saying that I know I messed up’d and y’all can roast me after it’s fixed.

In a moment of lapse judgement and gross negligence , I forgot to remove the reservoir cap while replacing pads and rotors on a 2015 V6 4x4 SR5. Doing the driver side wasn’t trouble, but starting the passenger side is when it all went bad!

Using a c-clamp to compress the pistons with an old pad forced a piston to pop out with a splash of brake fluid. Realizing now to late that I never took the cap off the reservoir, so I did my best to fix the piston back in place.

Brake pedal turned spongey. Tried to bleed the brakes and noticed one side of the caliber appeared to be seized. Brake pedal didn’t appear to engage the pistons on either rotor or retract even a bit to allow rotor some free play.

Read a lot of concerning mechanical issues that can be a result of my mistake for hours... Seriously, it still feels stressful. Not to know if this could lead to potential mechanical issues in the future

In a last resort to drive home, I did a “rebuild” by removing the caliber and pulling all 4 pistons for a cleaning and inspection. Disassembled it into 1/2 to rule out damage. Reused old parts to reassemble. Installed back on to truck. Bleed the brakes for the 4th time. Looks like it’s working.

However, I’m concerned about the brake pedal feeling mushy or shouldn’t it be stiff due to new pad thickness, but truck stops? Brake pedal still feels like trying to press down on thick mud, like if the foot was sinking in wet concrete.

I’m going to do a caliber rebuild using OEM rebuild kit ASAP tomorrow when parts department is open at the local Toyota...

I’d like to hear what the community recommends doing to prevent future mechanical issues to my truck?

 

Ummmm you posted this twice?

 

Phone died in the middle of it, so when I posted the first time it went to the wrong spot.

Trying to get this deleted, but can’t find an option.

 

These come in handy.
If the pads need to be separated from the rotor due to a groove in the rotor, I use 2 large screwdrivers to pry them back just enough to get the pads out.

 

I’ll be taking the caliber apart again.

 

Caliper
Good luck with repair!

 

When you press the pistons into the caliper, just break open the bleeder on the caliper and your good.

 

I redid my calipers a couple of months ago, if your piston working surfaces don't have any rust or scoring you can just get the rebuild kit which has the boots and the o rings, no need to replace the pistons. As for the mushy feel, just bleed them a little bit again, sometimes it takes time until the air bubbles settle down near the caliper bleed port.