Replacing Brakes

[Suprawill1]

Hi All,
Was replacing brakes on both axles. Did the front axle yesterday with no problem. Today, thinking the back would be easier, (and it should've been) I ran into a problem.
I can't compress the caliper piston so it would fit over the new pads. I made sure the brake fluid reservoir cap was off and the electronic parking brake was unplugged. I even opened the bleed screw to relieve pressure. I called and spoke with a mechanic friend and he said the caliper was bad. Ok, that happens. But when I tried to do the other wheel, I had the same problem. I find it ironic that both calipers were bad so I'm inquiring among some of you with experience to see if there's something I'm leaving out before I have to bend over and take a stealership price on 2 calipers because everyone else say's they don't stock them because they're too new on a 2020 ST. Appreciate the hits, thanks!

 

[Big Turk]

The piston screws in on the rear calipers.

 

[Big Turk]

That is standard on many models.

 

[Suprawill1]

The piston screws in on the rear calipers.

Man, that's the first I've heard of that! Been changing brakes on all of my vehicles as far back as I can remember and they all had compressible pistons or shoes in the back. How far off was I? lol
Thanks for the insight and I'll carry on with that technique tomorrow!

 

[Suprawill1]

@Suprawill1, Your calipers probably aren't bad but if the pistons have been forced they can be damaged. I haven't done brakes on my ST so I'm speaking from my experiences on other late-model Ford vehicles. Don't hold me to any of this.

I believe it's a good idea to put it into maintenance mode not simply unplug it. This is to protect the ABS system and I've heard the master cylinder but damaging the MC wasn't a concern for years. Having said that, if your bleeder screws are open when the pistons are compressed I don't think you can hurt anything. It's a really good idea to clean the boot well where it contacts the piston as the piston will be rotating on this surface and not simply be pushed in. Clean it with some Brake Clean and a brush and use a silicone spray around the seal.

A tool like the one listed below will make it easy to compress the calipers though it is not the only way. There are other $10 tools and I've seen where pistons have been butchered by using a set of pliers. You can usually "rent" these type of tools at AutoZone but they don't cost much (@$20) to own, having a set of caliper hanging hooks around is always a nice thing.

Some vehicles have both dedicated left-side (counterclockwise) and right-side (clockwise) and counterclockwise screw-in calipers others use just a clockwise screw-in on both sides. As I have done one I can't tell you what STs have. The rented kits I've seen only came with clockwise tools which is fine if that is all your vehicle has. You'll be able to determine which direction they screw in easily. If the piston doesn't turn, don't force it, try the other direction.

https://www.amazon.com/dp/B08RHMQF1Q?psc=1&ref=ppx_yo2ov_dt_b_product_details

I put silicone paste all around the rubber boot. I was unaware of the screwing process. I'm going to retry tomorrow with the ST in service mode and screw the pistons in. I looked at the vid in your link. Apparently, it was for a 2019 and I couldn't get it back out of service mode. Found a vid for a 2020 and there's an extra step to get it out.

I ordered that tool kit but won't get it till after the fact. Nice setup though! Thanks for the advice!

 

[Suprawill1]

@Suprawill1,
Integrated park brake calipers have had screw-in calipers for 25 years. You'd never have reason to know this if you haven't played with integrated calipers. Many vehicles use the drum in a rotor brake shoe park brakes and that's a different ball game.

My last vehicle was a 2012 Escape Limited and it had drums in the rear. That seemed counterproductive considering the 2005 Escape I had before that had disc. Neither were integrated systems.

 

[Suprawill1]

Thanks, I won't recommend that video again. As I said, many of your chain auto parts stores will have that tool for a no-charge rent, which might help you get through this one.

It's all good!

I tried an Auto Zone and they didn't have anything that intricate. Just your mainstream pusher styles, not screwers.
Now that I have the info you gave me, I believe I can make do.

 

[UNBROKEN]

The piston screws in on the rear calipers.

Incorrect. It retracts electronically.

 

[UNBROKEN]

You need to stop and familiarize yourself with the process first…and hope it doesn’t freak out when you plug it back in. You have to follow the process to put it into Brake Service Mode. This will automatically retract the pistons. After you do your work you follow the process to take it out of service mode and it will automatically set the pad height correctly.
It’s a very sensitive system…I hope you didn’t screw something up.
Putting the car into service mode is the ONLY correct way to do this. Disregard every other post in this thread.

 

[UNBROKEN]

@Suprawill1, Your calipers probably aren't bad but if the pistons have been forced they can be damaged. I haven't done brakes on my ST so I'm speaking from my experiences on other late-model Ford vehicles. Don't hold me to any of this.

I believe it's a good idea to put it into maintenance mode not simply unplug it. This is to protect the ABS system and I've heard the master cylinder but damaging the MC wasn't a concern for years. Having said that, if your bleeder screws are open when the pistons are compressed I don't think you can hurt anything. It's a really good idea to clean the boot well where it contacts the piston as the piston will be rotating on this surface and not simply be pushed in. Clean it with some Brake Clean and a brush and use a silicone spray around the seal.

A tool like the one listed below will make it easy to compress the calipers though it is not the only way. There are other $10 tools and I've seen where pistons have been butchered by using a set of pliers. You can usually "rent" these type of tools at AutoZone but they don't cost much (@$20) to own, having a set of caliper hanging hooks around is always a nice thing.

Some vehicles have both dedicated left-side (counterclockwise) and right-side (clockwise) and counterclockwise screw-in calipers others use just a clockwise screw-in on both sides. As I have done one I can't tell you what STs have. The rented kits I've seen only came with clockwise tools which is fine if that is all your vehicle has. You'll be able to determine which direction they screw in easily. If the piston doesn't turn, don't force it, try the other direction.

https://www.amazon.com/dp/B08RHMQF1Q?psc=1&ref=ppx_yo2ov_dt_b_product_details

Here are some quick instructions on maintenance mode:

https://www.youtube.com/shorts/i46H37_W_ZM

These are DOT 4 fluid brakes.



Integrated park brake calipers have had screw-in calipers for 25 years. You'd never have reason to know this if you haven't played with integrated calipers. Many vehicles use the drum in a rotor brake shoe park brakes and that's a different ball game.

You need to learn the process too because most of what you posted is incorrect and will cause someone issues.

 

[Big Turk]

Thanks for the correction.

 

[Big Turk]

Just looked it up, very interesting. Learned something major today.

 

[Suprawill1]

You need to stop and familiarize yourself with the process first…and hope it doesn’t freak out when you plug it back in. You have to follow the process to put it into Brake Service Mode. This will automatically retract the pistons. After you do your work you follow the process to take it out of service mode and it will automatically set the pad height correctly.
It’s a very sensitive system…I hope you didn’t screw something up.
Putting the car into service mode is the ONLY correct way to do this. Disregard every other post in this thread.

Thanks for the update Unbroken!
Yesterday, I put it all back together until I could get more info. Everything seemed to be in working order. I used the old pads until I could learn how to correctly retract the pistons. I did learn how to put it in brake service mode last night. Heading into it now with your advise and will update my progress.
Thanks again!

 

[edog]

Unbroken is correct, you need to use the brake service mode.
I don't have to do a brake job yet, and I already miss the drum in hat parking brake.

 

[GearHead_1]

I apologize for my previous post, and have pulled that post. It was not the procedure for the electric park brake. Those instructions were for a manual integrated parking brake.

 

[Cdubya]

Don't know about other methods but Forscan has service procedures for the brakes to work on them.

 

[UNBROKEN]

Y

Don't know about other methods but Forscan has service procedures for the brakes to work on them.

You don’t need Forscan or any scan tool to do this. It’s a simple procedure easily found on Google.

 

[Suprawill1]

Update:
I have successfully completed the rear brake job, thanks to all who chimed in!
Putting the ST into brake service mode allowed me to retract the caliper pistons. I had to manually compress them but did it by hand in opposed to using mechanical pad spreaders. The pistons had arrows on them showing they could be turned but didn't seem necessary. This was all I needed to complete the job I started yesterday.

Taking the bracket off so I could pull the rotors was a bear! Whoever previously removed them must've put thread lock on the bolts. It took all I had with a 19" long ratchet to completely remove them. Right down to the last few turns, they were as hard as the first turn!
Replaced the front brakes the day before without a hitch.
Thanks again for your inputs!

 

[deadhead20st]

Hi All,
Was replacing brakes on both axles. Did the front axle yesterday with no problem. Today, thinking the back would be easier, (and it should've been) I ran into a problem.
I can't compress the caliper piston so it would fit over the new pads. I made sure the brake fluid reservoir cap was off and the electronic parking brake was unplugged. I even opened the bleed screw to relieve pressure. I called and spoke with a mechanic friend and he said the caliper was bad. Ok, that happens. But when I tried to do the other wheel, I had the same problem. I find it ironic that both calipers were bad so I'm inquiring among some of you with experience to see if there's something I'm leaving out before I have to bend over and take a stealership price on 2 calipers because everyone else say's they don't stock them because they're too new on a 2020 ST. Appreciate the hits, thanks!

i did my front brake pads and rotors yesterday. i thought you only had to put it in service mode for the rears. When u was done. i started the ST to check brake pedal. I now have: Advance trac warning, uphill assist warning, pre-collision warning, parking brake system warning, and a couple others. No DTC's come up using the Torque app scanner. How do i clear these warnings?

Put it in and out of service mode did not do it. Also pulled the negative cable. No luck. Only thing i can think off is to pull both battery cables.

 

[Suprawill1]

i did my front brake pads and rotors yesterday. i thought you only had to put it in service mode for the rears. When u was done. i started the ST to check brake pedal. I now have: Advance trac warning, uphill assist warning, pre-collision warning, parking brake system warning, and a couple others. No DTC's come up using the Torque app scanner. How do i clear these warnings?

Put it in and out of service mode did not do it. Also pulled the negative cable. No luck. Only thing i can think off is to pull both battery cables.

Only used service mode for the rear brakes. Did the front without with no problems or warnings. Someone else would have to chime in as far as clearing your warnings. Good luck!