Shimano Ultegra R8070 Flat Mount Caliper Rebuild

[@denis_roy_7]

Didn’t know it could be done. Thanks!

[@pishpash75]

great video! the air hose trick is top notch - I was hesitant to pump the lever when caliper is still on the bike for fear of getting mineral oil everywhere

[@ivanteo1973]

don't the grease contaminate the mineral oil?

[@Ernie_13]

Loved the gag at the end! Caught me completely unprepared! 🙌 ….anyway I have a question: is rubber grease necessary, if we assume that mineral oil itself is providing good job to keep the rubber in good condition? And could dripping of mineral oil substitute rubber grease during assembly? Thanks for the answer. 🤟

[@LasseGreiner]

I would guess the grease will mix with the oil...

[@Ernie_13]

@@LasseGreiner yeah me too. But I’ve seen some ppl use thick grease during installation of olive (when installing hydraulic hose) and seems they have no troubles. But I prefer to use mineral oil in both cases, so there is no contamination from the grease.

[@lloydusdavies]

Very informative videos by the way. Thx.

[@denis_roy_7]

Merci!

[@panchnl]

Great video. I just did this last week, but I didn't take out the rubber seals. I used some 3000 grit sandpaper to lightly clean/polish the side of the pistons. My second piston didn't come out, but what worked for me is just using a bleed kit syringe. Fill it with some oil like normal and attach to the bleed nipple, then block off the seal opening with a finger to close the circuit and get the pressure going. Wondering though if the red rubber grease won't affect the brake oil? Used some fresh brake oil myself to put the pistons back in. Bit of a hassle the first time, but well worth the trouble.

[@maltesigmund1843]

Need the o ring sb an idea where I could get it?

[@AlexKost-tq6bj]

Typically most DOT hydraulic assemblies are rebuilt using Girling or Castrol red grease. It helps with bedding of seals and o-rings. It's specifically designed to not contaminate DOT brake fluid. Not sure if this is necessary for Mineral oil brakes - maybe just lube with mineral oil during installation and done? Or can just use a light silicone grease or maybe slicolium?

[@fastfish666]

many thanks for the very useful , out of interest what grease are you using for the seals - any silicone grease or something specific for mineral oil hydraulic fluid? Thanks - Pat

[@FreeToCycle]

Red rubber grease!

[@mpl1700]

can I also use assembly grease ( what I use for screws on the bike) for the rubber rings ?

[@rshank3499]

How do you use air to push out the pistons?

[@rlmurillo]

Great video. On my R8070 one piston works good the other is slower to get back in place or sometimes is not moving at all. Why is that?

[@pishpash75]

check your piston and piston seal for surface damage that could be causing drag. if that's all good it could be some debris in the oil channels that prevents even mineral oil distribution/flow when you squeeze the lever. good luck

[@moin6747]

thanks!

[@sriabhi]

So i got ultegra br8070 calipers from fb market. Didnot got any screws or plate with it. Now wat all i need to put on allez sprint disk bike ? With 160mm disk on front and 140mm disk on rear. Thanks.

[@thomasmoher9089]

Where do we find replacement parts? Are they available on the Shimano site or are there other suppliers?

[@hockysa]

where can you buy new orings from?

[@Ryan-nz5in]

Nice video. Where can we buy new rubber seals ?

[@jamble7k]

i dont think you can get official ones from shimano but there's plenty of knock offs on ebay

[@mykweb]

@@jamble7k Any Links. Becuase I had a perished O ring that seals the two half of the callipers and ended up having to measure and order via place online

[@weesenglim5904]

Any adverse effect if the brake fluid comes into contact with the grease?

[@FreeToCycle]

No! The grease is designed for use in braking and hydraulic systems.

[@channul4887]

@@FreeToCycle can you confirm the name of the grease you used here.

[@DovskiRae]

Hy, do you think its possible to use a 3mm disc with that caliper but not on a bike obviously..I have a 3mm x 200mm disc I'd like to experiment with, thx

[@moonte7933]

Shimano have a 3 mm channel between the faces of the caliper,so anything that is that thick is gonna rub like crazy and leave no room for adjustment...so no,i wouldn't use that.

[@dominicbritt]

Superb.

[@rosscads]

Did you replace the seals in this video, or just clean and regrease them?

[@FreeToCycle]

Clean and grease!

[@MB-uy9uz]

Hello I have a related question Does it help to lube the pistons with mineral oil occasionaly without taking them appart (in order to achieve same benefit) by removing pads cleaning caliper and working pistons in and out with à bit of oil on them. Some People say pistons shouldnt be lubed as the seal works as à return spring I have the same generation 105 brake and the pistons arent moving equally even after pushing both fully in and working the brake again Thanks Martin

[@AlexKost-tq6bj]

@@MB-uy9uz yes! There is actually an entire Park Tool video on KZbin showing exactly that. Whenever I change pads I slightly pump the brake to reveal more of the pistons, clean them with mineral oil (you can use DOT for SRAM or other DOT fluid brakes), and cycle them in-out a few times by pumping the brake lever and then pushing in the pads with a screwdriver or other. Lubricates the seal, cleans the contamination and you can visible see that the pads move better and smooth after.

[@octopusphysiotherapy9272]

Which exactly loctate are you using?

[@robertehernandez8394]

What size bit did he used to remove the two bolts to open up the caliper? Thanks.

[@jwattie144]

T30 torx bit

[@dungmac9038]

Good

[@ArjanGroe]

Hey, do you know of any good replacement piston seals? My piston are leaking on both my front and rear caliper, and Im very certain its because of the piston seals being old and worn.

[@liamcooper3836]

Did you ever find an answer to this?

[@thecappy]

Do you know of a tool to open the new one piece dura ace caliper?

[@FreeToCycle]

Haven’t come across one yet!

[@edward032786]

Hi, is this the same for all the road flat mount brakes, like the grx brrx400?

[@FreeToCycle]

Yes!

[@Fandestdh]

What grease is that?

[@marcelh-7084]

I think silicon grease

[@hanselp.2074]

Hi, what exactly is the purpose of doing this ? Just a service ? And why u use this „rubber grease“ ? Thx for your answer.

[@lloydusdavies]

I think rubber grease does not harm the rubber like some petroleum greases might I think.