Torn dust seal on R & L calipers

[naimc]

New here on the form. I have been servicing brakes on our vehicles for about 3 years, that means removing pads, caliper bracket, cleaning re-lubing slider pins with silicon grease, cleaning hardware re-assembly. Looks like this when I repaint the braket before final re-assembly

these are with the original Toyota pads and hardware.

Last year I replace Toyota pad and rotors on a 2019 Toyota Highlander with Raybestos Element 3 pad and rotors. This year during my annual service I was surprised to find a wear spot on both left and right calipers on the same location. No I really don't think I pinched the boot when compressing the pistons back last year. So I was wondering what could have caused this wear ? build up of brake dust ?

1st caliper :

2end caliper. Also the inner pad had brake material build up and refuse in the groves ?

I was told multiple times my calipers look like ****, I do live in Montreal , Canada so our road are covered with salt and slush for my months.

I have ordered new seals and as the piston's don't show and rust of pitting am going to re-man the calipers myself. No access to sand blasting so I am going the electrolysis rust removal method. Right now the caliper are bubbling away in an electrified brim.

Getting acceptible results I think, Un-treated caliper on the left, semi treated on on the right.

But I would like to know if I was going something wrong to cause that wear on the dust boots.

 

[Oro_O]

A very long-time acquaintance of mine from ClubLexus - the famous “SpeedKar99” - is also from Montreal and his cars look just as awful as yours underneath. I am so sorry for how badly they mis-manage your roads.

The thing that comes to my mind is worn piston seals. I’ve seen this before with that. The piston seals let fluid weep out and into the boot, especially the low point which is what that looks like. On compression, it won’t retreat enough and “bags” in the piston boot, keeping it from collapsing as it should. It bulges enough to then let the disc abrade it.

Clean the bores really well with crocus cloth, as well as the piston, and use new piston seals as well as boots.

Then move to Vancouver.

 

[The Critic]

I have seen this a lot on Toyota applications that use the 1324 style pads. I think those front brakes just get extremely hot and the rubber parts become crunchy and brittle. It is one of the few applications where I regularly see hot spots on the front rotors.

 

[CharBaby]

[naimc]: WELCOME!
I had the same issue with our Lexus RX when compressing the front pistons back into their bore. The dust boots would start to balloon in area(s) like yours and I would have to finagle a small screwdriver(between the rubber boot and the steel bore) and release the air.

All pistons boots can do this however I did noticed this would happen way more often on my particular Lexus RX...they just seemed a bit more fussy to push the pistons back into their bore sometimes making me wish I had a third hand. I don't believe that my boots had ever torn/bursted as in your pictures.

 

[Jetronic]

New here on the form. I have been servicing brakes on our vehicles for about 3 years, that means removing pads, caliper bracket, cleaning re-lubing slider pins with silicon grease, cleaning hardware re-assembly. Looks like this when I repaint the braket before final re-assembly

these are with the original Toyota pads and hardware.

Last year I replace Toyota pad and rotors on a 2019 Toyota Highlander with Raybestos Element 3 pad and rotors. This year during my annual service I was surprised to find a wear spot on both left and right calipers on the same location. No I really don't think I pinched the boot when compressing the pistons back last year. So I was wondering what could have caused this wear ? build up of brake dust ?

1st caliper :

2end caliper. Also the inner pad had brake material build up and refuse in the groves ?

I was told multiple times my calipers look like ****, I do live in Montreal , Canada so our road are covered with salt and slush for my months.

I have ordered new seals and as the piston's don't show and rust of pitting am going to re-man the calipers myself. No access to sand blasting so I am going the electrolysis rust removal method. Right now the caliper are bubbling away in an electrified brim.

Getting acceptible results I think, Un-treated caliper on the left, semi treated on on the right.

But I would like to know if I was going something wrong to cause that wear on the dust boots.

They likely got pinched when you put the caliper over the pads

 

[VTECOverRated]

I am glad I live in the south where I don't touch my brakes for like 100k miles and they still have life in them with zero rust.
This looks awful, really sorry you have to put up with such insanity. When you said you service your brakes for 3 years I wondered like "why?" but yeah, I remember living in Toronto and the rust was enough to cost thousands.

I think the reason that happened with the boot is the extra servicing. It is after all just silicone rubber, and will crack, and rip with use. And after being pinched (as the user above me said) it ripped.

So I guess RIP (pun intended).

 

[CharBaby]

Yes, living in the northeast or anywhere winters are brutal and the roads are salted regularly means that we often buy vehicles more often and spending more money than we'd like. However, we(mostly) only experience the winter(summers are short but wonderful) and not hurricane, tornadoes, flooding or intense heat. Sure, we can experience those isolated incidents but mostly winter is our downfall.

 

[naimc]

Thank you all for all the feedback, certainly confirms that these brakes require an annual inspection and re-grease.

The rest of vehicle is covered in WoolWax so it doing a pretty good job of keeping the rust away. I purchased a lifetime supply and that part of my annual routine re-coating.

While I am waiting for the replacement gasket kit and the Por-15 Caliper paint kits I am labering away at rust removal, after 48 hours the calipers look like this. Major improvement.

I have question regarding the pistons. They also had heavy rust, can I paint the insides with the Por-15 ? I looked for plastic heat resistant liners or heat resistant epoxy ?

 

[naimc]

A few mistakes were made along the way, but I still have all my fingers and the calipers are rebuilt, Used RockAuto seals the Toyota stuff was way too expensive $10 vs $120 !

 

[Vander1]

@naimc did you paint insides?

 

[naimc]

Inside of the caliper assembly no. that's bare exposed metal. I made foam plugs to seal off the inside.

I masked off the outside of the piston's and did paint the insides as they rusting heavily, electrolysis got most of the rust off the piston's then I used a small sand blaster with Soda to do a good job cleaning up before the primer and the final coat VHT caliper paint. ( that is the paint I had on hand)

 

[KrisZ]

This is a fantastic job, but please don’t tell me you do this every year?

I think the torn dust boots are from over servicing.
Did you put some silicone grease on these boots where they sit inside the caliper and the piston? If not, you should, it will provide another barrier for water entry and prevent rust on these machines surfaces.

If the seals are installed correctly and with some silicone grease, they don’t have to be touched at all of years. I would only lift them slightly to see if they are wet with brake fluid and to see a clean piston, that’s it.
Then I would lube the pins.
Rust, as unsightly as it is, does not affect the brakes when it is prevented from forming on critical areas, like pistons and dust boot mating surfaces. The rest is cosmetic only.

 

[naimc]

This is a fantastic job, but please don’t tell me you do this every year?

I think the torn dust boots are from over servicing.
Did you put some silicone grease on these boots where they sit inside the caliper and the piston? If not, you should, it will provide another barrier for water entry and prevent rust on these machines surfaces.

If the seals are installed correctly and with some silicone grease, they don’t have to be touched at all of years. I would only lift them slightly to see if they are wet with brake fluid and to see a clean piston, that’s it.
Then I would lube the pins.
Rust, as unsightly as it is, does not affect the brakes when it is prevented from forming on critical areas, like pistons and dust boot mating surfaces. The rest is cosmetic only.

Yes I live the rust belt and when I do my yearly woolwax coating I disassemble the brakes clean and re-grease. This year is the 1st time I have seen a tear like that in a gasket.

But I think I know why the wear occured on both calipers on the same spot. It must be the ****y Raybeston hardware, its just painted steel rusting away.

on both sides the tear in the dust gasket lines up perfectly with metal tab of the brake shim. which is rusting on both side and slight bent upwards.

You can see the marks where the piston are in contact followed by the tear in the boot. I clean-up the shims, they are lots of rust flakes. this was my re-assembly picture.

I am going back to Toyota tomorrow to purchase the real shim kits, its much more expensive but the sim are stainless steel I believe my olds ones from 2019 where in bunch better shape even after years of salt.

Picture taken in 2021 shims were 3 years old at this point.

 

[mrbreezeet1]

If those tabs did damage the boots, cut them stinking tabs off, and glue the shims on somehow. High tack or something.
Just an Idea.
And I am only calling them stinking tabs if/because they damaged the seals.

 

[naimc]

I am done with "jobber" shims . Back to the expensive, original Toyota shim kit. Sold separately does not come with pad, $57 here in Canada !

Look at the difference is thickness and surface area. Plus on magnet the Toyota shims have less pickup, that tells me less iron = less rust. Not sure if that is correct but that's my impression.

 

[KrisZ]

Yes I live the rust belt and when I do my yearly woolwax coating I disassemble the brakes clean and re-grease. This year is the 1st time I have seen a tear like that in a gasket.

I lived in the Greater Toronto Area for roughly 20 years, I know rust.
Re-greasing things is good, but do you also re-paint the calipers/bracket as well? If so and they look this bad after one winter, then this is a lot of effort for essentially nothing. I would use a better paint. I had good luck with rustoleum enamel paint.

I never had such issues. The worst was a sticking slider pin. I would inspect annually for uneven pad wear and lube the pins. That worked for me.

But I think I know why the wear occured on both calipers on the same spot. It must be the ****y Raybeston hardware, its just painted steel rusting away.

on both sides the tear in the dust gasket lines up perfectly with metal tab of the brake shim. which is rusting on both side and slight bent upwards.

You can see the marks where the piston are in contact followed by the tear in the boot. I clean-up the shims, they are lots of rust flakes. this was my re-assembly picture.


I am going back to Toyota tomorrow to purchase the real shim kits, its much more expensive but the sim are stainless steel I believe my olds ones from 2019 where in bunch better shape even after years of salt.

Picture taken in 2021 shims were 3 years old at this point.

I don’t think it’s the shim IMO. The tab is facing the other direction, plus the piston sticks out a bit from the boot. If the boot is touching the shim or back of the pad, that means there is air or fluid trapped underneath that makes it bulge out.

Still, it’s a good idea to use OEM shims, just don’t toss them out next year. They are perfectly reusable.

 

[naimc]

Both side, same pattern everything lines up. The tab has a slight lift to it. remember these pads were also cover with a layer of rust that clean off before taking pictures. There I a reason both caliper L & R show the same wear pattern at the same spot.

I was extra careful every year pushing the piston back, never saw any oil or air pockets trapped on the back side. Also when comparing the new gaskets with the old, there was clear difference in both, the old showing it had lost some of its elasticity.

My 1st set of original Toyota shims lasted 3 years. my mistake last year was to use the one's Raybestos provided.

 

[nascarnation]

Impressed with your WoolWax results. Wish they had that stuff 50 yrs ago when I lived in NE Ohio.

 

[Oro_O]

These comments aren’t timely but they may aid:

1) I also paint the inside of the piston as an anti-rust aid. Any paint will do, just mask the outside well or clean it up promptly.

2) Cleaning/de-rusting - nothing beats some good ole’ HCl for the heinous asbestos/pad dust/rust nightmare on these parts. I use the widely available, cheap pool Muriatic acid (31% HCl sol’n) mixed with water for about a 15% HCl solution.

I was really struggling last year to clean up some Volvo brake calipers and the dust shields. I brushed on the acid solution with a paintbrush, and it just melted off. This would be much, much faster and simpler than an electrolytic method. Also it leaves a nicely etched surface ready for priming and painting. Just do it in a well. Vented place, wear a mask, have a hose nearby or do it in a sink. This also works great for getting stubborn brake stains off wheels, just don’t leave the solution on a long time unattended. It will work very quickly and then you rinse it - it will not damage a properly cured painted or clear-coated surface used correctly.