f80 brake SS piston rebuild DIY?

[stevehifi]

Hi Guys,

Just wondering if anyone knows of a DIY on this forum or somewhere else that shows you how to replace the pistons with SS ones and also change the seals to high temp.

I found this kit and it looks promising:
https://racingbrake.com/bb-43bsp/

Thanks,
Steve

[aswy6]

Also interested

[jfritz27]

I have a front rebuild kit with high-temp boots on order from RB. Will be doing this as soon as it comes (though delayed due to high-temp boots being on back order ).

The PDF rebuild instructions put out by RB (linked on the product page) are pretty detailed.

For more, this one is great: https://www.2addicts.com/forums/show....php?t=1747800
If you clean the calipers thoroughly (using water), I would imagine you could accelerate the process by drying them in a ~275-300 degF oven. That's my plan at least

For track purposes, consider removing the dust/heat shield at the same time.

And while you're there, good time to switch out your front wheel bearings if need be:
https://f80.bimmerpost.com/forums/sh....php?t=1572940

[stevehifi]

Originally Posted by jfritz27

I have a front rebuild kit with high-temp boots on order from RB. Will be doing this as soon as it comes (though delayed due to high-temp boots being on back order ).

The PDF rebuild instructions put out by RB (linked on the product page) are pretty detailed.

For more, this one is great: https://www.2addicts.com/forums/show....php?t=1747800
If you clean the calipers thoroughly (using water), I would imagine you could accelerate the process by drying them in a ~275-300 degF oven. That's my plan at least

For track purposes, consider removing the dust/heat shield at the same time.

And while you're there, good time to switch out your front wheel bearings if need be:
https://f80.bimmerpost.com/forums/sh....php?t=1572940

very helpful.. thank you!

[jfritz27]

Just got notification that my RB rebuild kit shipped, guess they've got the high temp boots back in stock

Get 'em if you want 'em

[jfritz27]

So I tackled this today for my front calipers, first time doing this kind of thing. Not terrible, but a couple PITA parts. I gotta say, took longer than I expected. Just me doing it. This was nearly an 8h job (including some breaks), taking my time, ensuring things were cleaned well, and the bleeding (jesus, the bleeding...)

I used the DIY I linked above, as well as following RB's rebuild instructions to the letter for the hi-temp boots. Though my calipers aren't yet trackaddict-brown, the OEM dustboots were definitely toast.

Additional tips:

-An old cookie sheet makes for a good caliper workspace to keep the brake fluid from getting everywhere
-A cut-off finger from a latex/nitrile glove with a rubber band is a great way to seal off your SS brake lines while you're doing the job


- OEM PISTON REMOVAL: for those who've never done a rebuild, using the air compressor is a nifty way to get the pistons out. The trick though is to use enough blocking material in between the 2 sides to get ALL the pistons at least part of the way out before any one of them comes out completely (since otherwise you can no longer maintain a pressure seal to act on the remaining pistons). Wood works well in between, but if using cardboard, be sure to have enough of it in between. Use more material than you think you need to prevent excessive movement by a rogue piston, you can always remove to allow more travel. Particularly if boots are toast, there will likely be at least one piston that is kind of stuck, whereas others shoot out immediately. This gave me a problem for a while. Also, be sure to have a large channellock handy, best way to grab the last 1-2 pistons that are stuck (had to run and buy one). Since you're replacing them it doesn't matter if you mar it up. The DIY mentions prying with a screwdriver but that didn't work for me and I was afraid I was going to get it jammed in there worse

- OEM BOOT REMOVAL: this part also sucked up a lot of time. Mine were already torn at least partially when the pistons were seated, then when the pistons came out they completely separated (ripped away) from the boot's outer anchoring ring that sits -- very stubbornly -- inside the circumferential groove exterior to the piston bore. Not sure if the heat fused that ring to the caliper or what, but they were a bitch to get out. It just took a lot of patience with pick tools. Eventually you'll find a motion/angle where you see like half of the boot ring start to tilt up, then go with that and you should be able to pry it out.

- CLEANING: Generally followed what the DIY said, sprayed brake cleaner, used IronX on everything, then big flood of water through all the orifices. I did remove the 2 bleed nipple screws on each caliper. Then ran compressed air through everything thoroughly, followed by baking in a 275deg oven for ~10 minutes, followed by more compressed air. Seemed perfectly dry at that point.

- NEW PISTON/SEAL/BOOT INSTALLATION: Followed the RB instructions, everything went smoothly. Once everything was in, I covered all the pistons with gaffer tape (masking would work too I assume). I did this because I was paranoid that I would get brake fluid on the high-temp boots during the re-attachment of the caliper to the brake line, which is a bit awkward and will involve some spillage of brake fluid. I'm glad I did, I think I would have had a little contamination on one side had I not done so.

- BLEEDING: Jesus, F***ing, Christ. One thing that I did not see mentioned in researching this was how much fluid it takes to get all the air out of those front calipers. It takes ~3L PER SIDE of total volume to get the bubbles completely gone. This was with relatively frequent tapping of the calipers with a mallet and occasional pedal pushing. And no, I didn't have the bleed nipples opened too far (and sucked air in). It really takes that much fluid. Luckily ahead of time I got 3 L of cheap Motul 5.1 and used that. I put 2 L in the pressure bleeder (love the Schwaben unit), then recycled the fluid each time the drain bottle filled, back into the bleeder. I then did a DSC bleed for shits and giggles as I had a messy bleed happen last year related to a crappy Motive bleeder cap (and did get a little extra air out of the lines), then did a final bleed with the remaining 1 L of fresh fluid. The bleeding alone was ~2 hours I think. As first track day approaches I'll do a 2L SRF bleed.

That's pretty much all I can think of to add. Glad I did it myself, definitely saved some $$$. Obviously a shop would have been somewhat quicker, but with everything including the bleeding it's got to be 4h of labor for them MINIMUM (and not sure a shop would clean as well).

[hC1001]

Good job. A little late but the rebuild is pretty much the same for all 4 piston brembo/stoptech caliper.

Have you thought about titanium backing plates? Ive had good success with them in the past. These brembo calipers on the F80/82 also contract to fit the plates with brand new pads.

[jfritz27]

So now that I've driven the car around a bit, I've got a somewhat spongy brake pedal I was damn positive after all that fluid flushed (and with a DSC bleed) there were no more bubbles, but I suppose there could be some still hiding. In googling this sounds like this is not entirely uncommon after a rebuild. People talk of things like piston hysteresis; or something else related to fact that grease (instead of brake fluid) was used to lube the seals; all things I'm not sure I fully understand.

Going to drive it through this weekend and see if I get lucky with it firming up on its own, otherwise back to the bleeding with some more fluid. At that point may do a more conventional 2-person pedal bleed. I'll graciously take any other words of wisdom people may have...

I do have the titanium shims as well

[hC1001]

Originally Posted by jfritz27

So now that I've driven the car around a bit, I've got a somewhat spongy brake pedal I was damn positive after all that fluid flushed (and with a DSC bleed) there were no more bubbles, but I suppose there could be some still hiding. In googling this sounds like this is not entirely uncommon after a rebuild. People talk of things like piston hysteresis; or something else related to fact that grease (instead of brake fluid) was used to lube the seals; all things I'm not sure I fully understand.

Going to drive it through this weekend and see if I get lucky with it firming up on its own, otherwise back to the bleeding with some more fluid. At that point may do a more conventional 2-person pedal bleed. I'll graciously take any other words of wisdom people may have...

I do have the titanium shims as well

I hope you guys capped the hardlines b4 removing the calipers. That way the entire system doesnt drain out.

I like to drive the car around for a couple days driving over rough roads and sewer caps to move any trapped air bubbles and then do another bleed. Im talking pressurizing the system and then open each valve for a second. Might have to do this more than once if there is air trapped inside the system. If you hear/see fluid spraying out, there is still air inside the system. If the fluid flows out slowly, close the valve and move onto the next.

[SYT_Shadow]

Instead of capping the hardlines you can just press the pedal all the way down with a piece of wood. It'll prevent fluid loss.

[FrankMstein]

Where do you guys get your Ti shims? Yperion?

[jfritz27]

Originally Posted by FrankMstein

Where do you guys get your Ti shims? Yperion?

I bought mine used a while back (can't remember if from classifieds here or eBay, I think it was eBay), but I believe they are the Yperion ones as I recall them having the same logo

[D_SheerDrivingPleasure]

I just got fronts from this seller. Rears unavailable currently.

[FrankMstein]

These are cheaper
https://www.opmustang.com/store/p340..._FRONT_.html#/

[jfritz27]

Originally Posted by FrankMstein

These are cheaper
https://www.opmustang.com/store/p340..._FRONT_.html#/

These appear to be only for the M "BBK" that is available on the M2C -- different size (larger) pads than the standard F8x blue caliper setup.
I actually emailed them last year asking about making shims for the standard setup and they hinted that maybe that would be coming, but looks like not...

[FrankMstein]

Yeah, that is what I'm looking for. See avatar <---

[jfritz27]

Originally Posted by FrankMstein

Yeah, that is what I'm looking for. See avatar <---

Ahh.... in that case....

[uncle ben]

Just ordered front and rear shims from yiperion. They make titanium brake caliper pistons for some calipers. Too bad they don’t make them for the f80. I’m sure that titanium pistons would be even more of an upgrade over the stainless ones.

[SYT_Shadow]

Originally Posted by uncle ben

Just ordered front and rear shims from yiperion. They make titanium brake caliper pistons for some calipers. Too bad they don’t make them for the f80. I’m sure that titanium pistons would be even more of an upgrade over the stainless ones.

that would be incredible

[FrankMstein]

Originally Posted by uncle ben

Just ordered front and rear shims from yiperion. They make titanium brake caliper pistons for some calipers. Too bad they don’t make them for the f80. I’m sure that titanium pistons would be even more of an upgrade over the stainless ones.

Good luck getting them ... from Russia. Update us. Is the Ruble up to $0.01 now? How did you pay him? Are some forms of payment even going into that country? I was planning to buy those but, not now.

[uncle ben]

Originally Posted by FrankMstein

Good luck getting them ... from Russia. Update us. Is the Ruble up to $0.01 now? How did you pay him? Are some forms of payment even going into that country? I was planning to buy those but, not now.

Found him on Instagram and used PayPal. Pretty affordable for the front and rear set ($235 Canadian). Hopefully they get here.

[uncle ben]

Originally Posted by SYT_Shadow

that would be incredible

He got back to me. Says they can make a titanium set for around $700. Pretty pricey, but it would be a big improvement I’m sure.

Just wonder if the money spent between shims, pistons, seals and giro rotors, a person isn’t just better off buying a bbk.