Hello All,

I have to replace my rear left caliper and wanted to verify if I should have the car running when I pump the brakes to fill the new caliper as well as when I bleed the air.
I will be doing the procedure with an assistant. Thanks in advance.

 

I would recommend using a pressure bleeder at 15psi. I could never get the air out of my replacement caliper doing the normal brake pedal method, car on or off, until I got a pressure bleeder.

 

I love my pressure bleeder.

Here are my tips for replacing a caliper…
First, before removing the caliper, depress the brake pedal and lock it in place. This might sound counterintuitive, but it sets the master cylinder piston in place to prevent fluid from draining out when you disconnect the caliper hose. Then, when the work has been completed, and the caliper has been replaced, unblock the pedal and proceed with the pressure bleed on the replacement.

When bleeding the air out of the replaced caliper, crack the bleeder screw very slowly. You want whatever air in it to compress from the pressure bleeder. You want the fluid coming in to displace the air as slowly as possible. This makes sure you have no entrained air left in there.

Like most automotive maintenance tasks, it can be intimidating at first, but take your time and it will turn out well.

 

Most appreciated!