Caliper prev maintenance

[Donald]

So at some point in a caliper's life it's likely to seize. Maybe more so in the rust belt. Brake flush may prolong the caliper's lifem

Most mechanics push the pistons back in and if it goes in reasonably easy then the caliper is good to go.

But if the caliper seizes (piston) or similar 5000 miles after you changed the pads you are not likely to notice until the pad is ruined.

So at what mileage would it make sense to replace or rebuild the caliper as prev maintenance against premature pad failure.

I assume this only makes sense if you do your own brakes.

 

[supton]

I've had a caliper or two seize like you have mentioned, but I don't think it always kills the pad--if you catch it soon enough. My vehicles are all low powered though, so any brake drag is quickly felt (and smelled).

I've thought about putting in a block of wood and stepping down on the pedal, so as to get the piston out as far as I'd dare. Then packing some red rubber grease onto the piston, then running back in. Do that early on, long before rust can get in. I'm guessing it will only be good for a year (might not even be that, no idea how fast it will evaporate off--we're light brakers so I expect longer life than some who are hard brakers).

OEM calipers though have been going 10+ years for me. YMMV. That's one or two brake jobs.

 

[Rust_Belt_Pete]

So two things
1. Cheap laser thermometer. Once in a while compare rear left and right temperatures and front left and right to see if there is significant temp difference (don't compare front and back). This may give you an indicator.

2. There is no mileage or age in the rust belt to indicate imminent failure. I saw multiple times where the rust ate around the caliper piston dust seal.
Inspect your caliper piston dust seal to make sure it's intact.
Some like to add that red toyota rubber grease under the seal some like to spray silicone oil there. Your call. Either way inspect your dust seal. Especially the rear that retracts by turning.

 

[Rand]

So at some point in a caliper's life it's likely to seize. Maybe more so in the rust belt. Brake flush may prolong the caliper's lifem

Most mechanics push the pistons back in and if it goes in reasonably easy then the caliper is good to go.

But if the caliper seizes (piston) or similar 5000 miles after you changed the pads you are not likely to notice until the pad is ruined.

So at what mileage would it make sense to replace or rebuild the caliper as prev maintenance against premature pad failure.

I assume this only makes sense if you do your own brakes.

This can also depend on the type of caliper.

 

[Rust_Belt_Pete]

Oh should have added something else! Clean and grease your caliper pins once a year. If you have the fixed caliper clean and check the retaining pins.

 

[Donald]

Oh should have added something else! Clean and grease your caliper pins once a year. If you have the fixed caliper clean and check the retaining pins.

The caliper pins and boots should be cleaned, inspected and lubricated with each change of the brake pads.

But most don't do much with the caliper piston if it goes back in relatively smoothly.

 

[Rust_Belt_Pete]

Many rear calipers turn in their axis for parking brake/e brake.
Often the runner seal can get dried and stuck on the piston. You can twist it and rip it retracting the piston.
That's why I have a plastic pick and a can of silicone spray on standby

 

[iCurious]

If you cannot retract the pistons in with ease, it's probably time to consider.

 

[shortyb]

I suppose it's one of those situational maintenance things and not necessarily a set mileage one. Live in a dry, no road salt area you could probably go quite a while before any maintenance is needed. Conversely, if conditions are severe, might want to consider more often, like annually at a minimum. I do regular fluid flushes and inspections on all my vehicles brakes. During flushes, I always check the ease with which to retract caliper pistons and condition of the dust boots. Especially the rears since the pistons have to be turned back it . Pins get checked for free movement and greased. If the pistons are difficult to push back in, or the boots are looking really tired, its rebuild time. All of mine are single piston and super easy to do. Only had to replace a front set of calipers once as the pistons were very corroded and had scored the bores pretty badly.

 

[Donald]

I suppose it's one of those situational maintenance things and not necessarily a set mileage one. Live in a dry, no road salt area you could probably go quite a while before any maintenance is needed. Conversely, if conditions are severe, might want to consider more often, like annually at a minimum. I do regular fluid flushes and inspections on all my vehicles brakes. During flushes, I always check the ease with which to retract caliper pistons and condition of the dust boots. Especially the rears since the pistons have to be turned back it . Pins get checked for free movement and greased. If the pistons are difficult to push back in, or the boots are looking really tired, its rebuild time. All of mine are single piston and super easy to do. Only had to replace a front set of calipers once as the pistons were very corroded and had scored the bores pretty badly.

And what is your guess as to the cause of the pistons being corroded?

 

[shortyb]

And what is your guess as to the cause of the pistons being corroded?

Bad seals let moisture in I suspect. Corrosion tore up the seals more and the cycle just got worse.

 

[Donald]

Bad seals let moisture in I suspect. Corrosion tore up the seals more and the cycle just got worse.

I helped a friend with a leaking caliper. He was dripping brake fluid and adding brake fluid to the reservoir every few weeks.

Never had a chance to pull the pistons out and see what was going on.

With the high pressure of a brake pedal I would think a bad seal would mostly let brake fluid out and not much moisture in.

 

[shortyb]

I helped a friend with a leaking caliper. He was dripping brake fluid and adding brake fluid to the reservoir every few weeks.

Never had a chance to pull the pistons out and see what was going on.

With the high pressure of a brake pedal I would think a bad seal would mostly let brake fluid out and not much moisture in.

Hard to say. Possibly exposed area of piston corroded and caused seal compromise. Either way, the seals were torn up and pistons were almost corrosion locked in the bore.

 

[Rust_Belt_Pete]

If you live somewhere around the great lakes/lake effect areas you get the worst of snow and salt AND year round high moisture levels so your fluid goes bad fast.
Also the corrosion gets so bad that I watched multiple caliper dust seals get rust jacked off the piston or the casting and let the water in.

 

[Tundragod]

Rust belt here. I had to do both of my 11 MDX rears:
10/12/2023 145,814 CALIPER Right Rear 07-13 ACURA MDX REAR RIGHT OEM LOT3293 used
03/15/2024 147,135 CALIPER Left Rear AutoShack Rear Brake Caliper Driver Side
I had no choice but to replaced the seized.
Even if it didn't seized, It is just too much frustration, and I quote "frustration" trying to replace the seal.

 

[Rust_Belt_Pete]

Rust belt here. I had to do both of my 11 MDX rears:
10/12/2023 145,814 CALIPER Right Rear 07-13 ACURA MDX REAR RIGHT OEM LOT3293 used
03/15/2024 147,135 CALIPER Left Rear AutoShack Rear Brake Caliper Driver Side
I had no choice but to replaced the seized.
Even if it didn't seized, It is just too much frustration, and I quote "frustration" trying to replace the seal.

Let me guess the caliper piston dust seal had the hard outside and was basically impossible to drive in with the screw in piston?

 

[slacktide_bitog]

For rear calipers that also contain the parking brake, it might be worth replacing the calipers with the pads and rotors, if you have to deal with rust.

Also, you must use the parking brake regularly. Not using the parking brake when it's integrated into the rear caliper/pads will cause premature caliper failure.

 

[JimPghPA]

When I changed brake fluid and cleaned and lubed everything on my crv in 2021, I opened the bleadees before compressing the calipers. The front passengers side caliper was full of black fluid, where as all the others had regular color. I was glad I did not just force it back up into the ABS and master.

 

[Rust_Belt_Pete]

When I changed brake fluid and cleaned and lubed everything on my crv in 2021, I opened the bleadees before compressing the calipers. The front passengers side caliper was full of black fluid, where as all the others was regular color. I was glad I did not just force it back up into the ABS and master.

This is why I love positive pressure bleeders.

 

[Jetronic]

I helped a friend with a leaking caliper. He was dripping brake fluid and adding brake fluid to the reservoir every few weeks.

Never had a chance to pull the pistons out and see what was going on.

With the high pressure of a brake pedal I would think a bad seal would mostly let brake fluid out and not much moisture in.

with brake fluid so attracted to moisture, it will travel into the fluid at the calipers at all times.