4th Gen Front Brake Caliper Siezed

[Chrisygirl17]

For the third time in 4 years I have had both of my front brake calipers seize, thank god for Shucks/O'reilly's warranty so I have not had to pay for replacements.

But I am curious is anyone has some insight into why they keep seizing.
Has anyone had simular issues?

I am not sure if I am doing something wrong or if it is just cheap calipers.

Thank You for the help.

 

[preacher35]

Is your T4R sitting for long periods of time without being driven? When you install the new calipers, are you greasing the pins real good? On my previous SUV (Xterra), it would sit in the driveway for months at a time and eventually, a caliper would seize. One time, it only took five weeks. Put a really good lithium grease on the pins when you install the new caliper/s and you should be in pretty good shape.

 

[Chrisygirl17]

It is my daily so the longest it will sit is 24 hours, as for the greese yeah i greese the pin's as well as the back of the brake pads.

Thank youf rot eh ideas though

 

[Bob J]

My theory is that it is a combination of the material used to manufacture the caliper piston and water in the brake fluid.... I'm amazed that flushing/replacing the brake fluid is not part of the regular maintenance schedule.....

 

[BlackWorksInc]

My theory is that it is a combination of the material used to manufacture the caliper piston and water in the brake fluid.... I'm amazed that flushing/replacing the brake fluid is not part of the regular maintenance schedule.....

Should be every 30k or so, I haven't really heard of anyone not using something close to that...

 

[M1911]

Welcome to the club.

 

[ghs215]

How do you know it is seized up? What does it look look like? Signs? Pics?

The reason I ask is that I have not don't the brakes yet on my 4Runner yet (bought used @ 120K mi). I have done brake caliper replacements before so I am familiar with the general knowledge.

 

[Ukraine Train]

If it's bad enough, the car may pull to one side all the time, you might smell the brakes overheating, rotors might warp, and pad wear will be uneven. You can check for it pretty easily by pulling the wheels off and prying a screwdriver between the rotor and pad to see if the piston recedes into the caliper easily. There is a spot by the anti-rattle clips where you can wedge a screwdriver and push against the pad backing plate, so that you don't gouge the actual friction material. I just did this on the '03 I recently bought and found one piston to be much harder to depress than the others. I think I'll try to replace just the one piston so I don't have to replace both calipers yet.

 

[WXman]

My theory is that it is a combination of the material used to manufacture the caliper piston and water in the brake fluid.... I'm amazed that flushing/replacing the brake fluid is not part of the regular maintenance schedule.....

As often as these junk Toyota calipers fail, there is no need for a brake fluid replacement interval because it gets replaced naturally during all the caliper changes and bleeding.

I've had dozens of vehicles and some with over 200K on the clock and I've never replaced brake fluid once in my life, nor have I ever had it recommended to me by any service dept. or shop, and I've never had any trouble.

Fortunately, this 4R had the work done by the PO.

 

[stanleybb50]

As often as these junk Toyota calipers fail, there is no need for a brake fluid replacement interval because it gets replaced naturally during all the caliper changes and bleeding.

I've had dozens of vehicles and some with over 200K on the clock and I've never replaced brake fluid once in my life, nor have I ever had it recommended to me by any service dept. or shop, and I've never had any trouble.

Fortunately, this 4R had the work done by the PO.

^^ this.

 

[Bob J]

How do you know it is seized up? What does it look look like? Signs? Pics?

The reason I ask is that I have not don't the brakes yet on my 4Runner yet (bought used @ 120K mi). I have done brake caliper replacements before so I am familiar with the general knowledge.

Many threads on this but the best way to be sure is pull the wheel and check.... Look for uneven pad wear and try and depress the pistons....

 

[BlackWorksInc]

If it's bad enough, the car may pull to one side all the time, you might smell the brakes overheating, rotors might warp, and pad wear will be uneven. You can check for it pretty easily by pulling the wheels off and prying a screwdriver between the rotor and pad to see if the piston recedes into the caliper easily. There is a spot by the anti-rattle clips where you can wedge a screwdriver and push against the pad backing plate, so that you don't gouge the actual friction material. I just did this on the '03 I recently bought and found one piston to be much harder to depress than the others. I think I'll try to replace just the one piston so I don't have to replace both calipers yet.

Its not just Toyota's aluminum calipers that sieze up, other manufactuers have the same issue with disimilar metal calipers of varying severity.

As for you, that's great that you're brake fluid has absorbed water and corroded the inside of your system for 200k without any failures, you're lucky...ish. The scientific fact is that Brake fluid IS hygroscopic, it WILL absorb water. The entire reason there are varying types of brake fluid is in part due to this reason. You're 200k fluid is saturated with water and thus in a potentionally severe braking or prolonged braking situation that fluid will boil more readilly than fresh fluid.

Granted the situations that would happen in are rare, but I'd rather know I spent a few bucks to keep something as important as my braking system in top condition than just let it languish and hope it doesn't fail in that 1% that I really need it. The other issue is going to be corrosion in the system that can contribute to siezed calipers, premature failure of seals, and other components. Like I said, you're lucky nothing has gone pear shaped in that much mileage if you haven't changed the fluid. But that doesn't mean your braking system is in good condition, just that it hasn't failed yet.

My point isn't to rag on you, its just to point out that just because you're that 5% that hasn't had any issues when not properly maintaining your car doesn't mean its the right thing to do. That's like saying just because one guy had a Chrysler that DIDN'T just fall apart due to being a pile, ALL Chryslers are good cars; and we all know the truth about that.

 

[stanleybb50]

What percentage of the population do you think actually has their brake fluid changed/flushed is a good question. Those all over the forums do so, but even then, I'd be willing to bet a good percentage of those on here don't even do it. (Just saying.)

Most people don't even flush their coolant, or change their diff fluid, or trans fluid, or power steering... Just oil, tires, windshield wiper fluid.

Above, I was referring to my past, like the cars I had in high school etc.. Lol dirty a** fluid. I just didn't know, but never a problem. I "thought" I was anal about my car maintenance too...

I think the importance of flushing brake fluid, and it's impact is being way blown out of proportion. They are seizing because water/salt is getting behind the boots and hitting the pistons directly. Not from the tiny bit on the back side with the fluid.

 

[BlackWorksInc]

What percentage of the population do you think actually has their brake fluid changed/flushed is a good question. Those all over the forums do so, but even then, I'd be willing to bet a good percentage of those on here don't even do it. (Just saying.)

Most people don't even flush their coolant, or change their diff fluid, or trans fluid, or power steering... Just oil, tires, windshield wiper fluid.

Above, I was referring to my past, like the cars I had in high school etc.. Lol dirty a** fluid. I just didn't know, but never a problem. I "thought" I was anal about my car maintenance too...

I think the importance of flushing brake fluid, and it's impact is being way blown out of proportion. They are seizing because water/salt is getting behind the boots and hitting the pistons directly. Not from the tiny bit on the back side with the fluid.

I agree with you, I think the majority of siezed calipers are from the salt belt and due to road salt and/or ocean salt. But there are people who swear it can't be the cause of it, so I think poor brake fluid service and a combination of moisture attacking from outside can create this issue.

 

[zopperman]

im should probably change my brake fluid... :roadkill:

 

[V8Man]

The design of a four caliper system, while it distributes the forces more evenly on the pads, the pistions move less. Quicker reaction times too before everything starts doing their job. The amount of fluid in the tiny line, is distributed to 4 pistons. They have to move very little to do their job on a daily basis. Compair that to the movement of the one pistion system. Similar size brake line moves one pistion, if it sticks you know it right then. No driving around for weeks in the slop and stuff with only part of your system working. The Old Kelsie Hays four pistion calipers on my '65 Mustang have the same problem. The water in the fluid is another problem. If you what to really fix that, change your fluid to a DOT 5 synthetic. I have it all my classic cars that don't get driven everyday. No stuck calipers or drums.

 

[BlackWorksInc]

The design of a four caliper system, while it distributes the forces more evenly on the pads, the pistions move less. Quicker reaction times too before everything starts doing their job. The amount of fluid in the tiny line, is distributed to 4 pistons. They have to move very little to do their job on a daily basis. Compair that to the movement of the one pistion system. Similar size brake line moves one pistion, if it sticks you know it right then. No driving around for weeks in the slop and stuff with only part of your system working. The Old Kelsie Hays four pistion calipers on my '65 Mustang have the same problem. The water in the fluid is another problem. If you what to really fix that, change your fluid to a DOT 5 synthetic. I have it all my classic cars that don't get driven everyday. No stuck calipers or drums.

I've looked into changing to a DOT 5 fluid, but its not advised according to Toyota and most people I talk to. The problem is that when switching to a DOT 5 you need to flush everything, run denatured alcohol through the system, and replace the "contaminated" seals; the synthetic stuff doesn't play well with the old stuff.

The other issue that comes into play is that DOT 5 is not designed for use in ABS systems as its fluid characteristics are different than DOT 3/4 (I can't remember it if was viscosity or what not.) Combined with the lack of a rebuild kit for the seals and gaskets in our ABS/VSC systems, DOT 5 is just not possible in a stock 4Runner.

I've thought about going with a DOT 5.1, which is supposed to be a non-synthetic version of DOT5 with similar boiling point and characteristics, but be safe in DOT 3/4 systems. So far I don't have enough information on DOT 5.1 to justify the cost of switching over and if that provides any benefit; I also believe 5.1 is hygroscopic as well.

http://www.toyota-4runner.org/4th-gen-t4rs/139051-dot4-vs-dot5-1-brake-fluid.html

 

[V8Man]

Didn't think about the ABS, Works great in the older cars. Flushing and replacement of the soft parts isn't too bad of a job either. If you keep a car long enough you have to do that anyway!

 

[M1911]

The design of a four caliper system, while it distributes the forces more evenly on the pads, the pistions move less.

I don't understand how this can be. The pads move from their rest position until they are pressing against the rotor. That distance is the same whether the pads are getting pushed by 4 pistons or one. The stroke of the piston is the same. The difference is that in a 4 piston caliper, each piston has less force on it, but the distance the pistons move is the same.

 

[V8Man]

You are correct the force on each piston is reduced. A disk brake system has two gaps between the disk and the pads, one on the inboard pad and one on the outboard pad. In a single piston system, the piston moves to take up that distance on both sides. On a multidisc system the inboard and outboard disks move half the distance of a single piston. And since we are talking about a couple of thousands of an inch of total movement in a system it is less in a multidisc.