Does anyone just not bother to install caliper dust boots at all?
Here's mine after a rebuild and 1 set of PFC08s (Porsche/Brembo calipers):
Yeh, "real" race car calipers don't have dust boots. I don't think you need them as long as you inspect them regularly and rebuild as needed.
That's kinda where I'm headed. I'll clean up the pistons (brake cleaner, compressed air) as much as possible prior to installing new pads. But otherwise, I think I'll just remove and not replace the burned up dust covers. I'd hope I could get through 3-4 sets of pads before having to rebuild seals.
Fronts. Do you have OEM M3 calipers?
I have a friend with Brembo's on his 135i, he says his dust boots are burned up after just a few days.
EDIT: Maybe this is where phenolic pistons come in to play?
Last edited by aeronaut; 03-28-2017 at 07:04 PM.
When i had a Stoptech ST40 kit on the car, the boots held up fine. fwiw. Maybe Brembo has another boot option. Or maybe titanium shims would help keep heat off the pistons. Ultimately, i think you're fine without boots, especially if its not a street car.
Interesting.
Yea, I should probably try something other than the centric dust boots from Rockauto. But still.
It's mostly track. Call it 2000 mi/year road miles.
+1 on TXBDan's reply, the stoptech grey silicone dust boots hold up better than the black rubber ones.
You can also get titanium heat shields. I had them on my stock calipers and i have them on my stoptech calipers. I use them more for stopping the heat transfer to the aluminum pistons than burning dust boots. No drawbacks except when you install brand new pads, no space to fit the shields...
You know, I've got a bit of a odd history on the dust boots on these. Bottom line, I mixed the brands. I haven't looked at the dust boots from the right caliper to see if they are burned.
That said, I know some of the dust boots I used were the gray silicon (Centrics from Rockauto). Some may have been the black ones.
I'll update when I have more info. And may try actual stoptechs at my next rebuild.
Where do you get your stoptech dust boots?
EDIT: I just realized StopTech is a division of Centric.
Last edited by aeronaut; 03-29-2017 at 07:58 AM.
I bought some lower-brand boots to rebuild my stock E36 non-M calipers. They were brittle and worthless after one weekend. The OEM dust boots are better but are still toast after a season. I also don't have brake cooling ducts installed yet so that's certainly not helping.
Just get rid of them.
For the record:
So looking at my notes, I had 3 types of dust boots installed. Brembo (black), Stoptech Silicon high temp (gray, $10/ea), and Centric (gray, $15 for a full caliper rebuild kit). FYI, the cheap Centrics look exactly the same as the $10 StopTechs. None of those gray ones seem to fit tightly.
The only ONE that had failed was the Brembo. The others that I thought had failed were simply covered in crud. So I easily popped out the bad Brembo and popped in a new Centric.
Failed Brembo:
New gray Centric on top, and used Centric or Stoptech on the bottom.
Lesson learned, inspect further before panic.
I doubt I'll have boots after my next rebuild.
Boots or no boots?
Well, it all depends on the pistons' material. Race calipers (good ones at least, not the race-looking street stuff) use pistons made from stainless or titanium. No boots is needed as the material is very hard and will not get easily damaged by brake dust. It will not corrode either like aluminum or chromed pistons do.
I wouldn't go without dustboots on a caliper with aluminum or steel pistons.
Motorcycles often have chromed steel pistons and don't have dustboots. But on top of the usual oil seal, they also run a dust seal.
PS- Whenever you change your dustboots, I suggest popping the pistons to clean them up and inspect for damage.
1969 2002 racecar + 1989 e30 M3 racecar
Lee, you're a wealth of knowledge and experience, thanks!!!!!
Anybody run stock E36 calipers with no dust boots at all? I was just swapping brake pads and noticed one of my boots was popped out. I know it doesn't do any sealing, but i wonder if the part at the inner lip helps keep the piston centered and tracking straight.
I have a new rebuild kit on the way, but it'll be a scramble to get rebuild the caliper in time.
Cool, thanks for confirming. It'll only be for the weekend at WGI. I"ll rebuild it when i get back.
Good topic actually! I think these dust boots are a must, especially when it comes up to protection, even if the exploitation term is not so long. The only things is, of course, to choose a model that would be worth from the price-quality viewpoint. It's the same as I chose to buy a dust collector from https://mitersawjudge.com/best-dust-collector-reviews/ for my job to protect me. I will go to make a check on mine for any damages, but I am also thinking to make quick research for better models. This actually remembered me that I should make some maintenance work for the whole engine.
Last edited by Jerry992; 01-18-2021 at 04:20 PM.
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