III Pro PEERAGE 4 brakes - piccola clone

[Tijoe]

Does anyone have a link to a IIIPro 4-piston caliper rebuild kit?  One of my rear caliper's pistons has started leaking and sucking in air.   (All things considered, not many hours of usage on these calipers.)

[radler36]

I bought a set a couple of weeks ago and only got to fit them on Saturday. I can't use the bike they're on right now until I get tyres but the brakes were a doddle to set up. I did have the trim the front hose but the rear was only just long enough for my bike. The brakes arrive pre-bled and I didn't realise they had a shorter hose from the lever that the remaining hose connects to. I like that a lot and bleeding the rear brake was just the same as shimano. Brakes feel nice but there is a lot of pull on the lever to require the pistons to move. I'll have to update here once I get riding them. They look great and weighed 400g with pads for front and rear once front hose was trimmed about 150mm.

Any updates yet? How do they perform in terms of braking power if you compare them to XTR or Level brakes?

[ZacItaly15]

The iiiPro post and flat mount brakes share similar components like bleed screw. I'm curious if I could use the post mount brakes on a gravel build for more stopping power.

I do.
I just installed few days ago the XG4 / IIIPRO flat mount kit with GRX shifters in my gravel bike.
Quite annoing bleeding but now it works.
Need to brake in the pads but "i got the power" now comprared to Apex

[ZacItaly15]

Front Brake

[nevar.karasu]

Anyone know best way to bleed these? I accidentally introduced air into the lines of the front brake and now it doesn't work, eck.

[Daviddavieboy]

Anyone know best way to bleed these? I accidentally introduced air into the lines of the front brake and now it doesn't work, eck.

 Sorry no, I am not a urologist. Perhaps someone here is ? - Apologies, I am watching Paris-Roubaix and it is a bit boring right now.

[ZacItaly15]

Anyone know best way to bleed these? I accidentally introduced air into the lines of the front brake and now it doesn't work, eck.

I highly suggest to try the autobleed technique. Use a rubber band and press the front brake lever up to the lever touches the bar. Let the brake at least all the night long or up to 24h.
This will help to let the bubble move from the caliper to the lever
Then, release the lever and fill the front lever reservoir with oil using the shimano funnel
With the funnel full of oil, start squeezing the lever very short and very fast. Many small bubble will go up.

Do this 2/3 times in a week

In case of "severe" air trapped between the piston, squeeze the piston without bleedblock or rotor in order to "over expose" piston. Then, reset the piston with something flat (be carefull with ceramic piston edges)

[Tijoe]

I can state that I am to the point that I can't recommend the IIIPro products anymore.   I have had 4 calipers fail  (I purchased 5 sets total of the IIIPro E4 brakes)
4 calipers having issues is too high of a percentage failure rate.   

The seals start leaking between the piston and seal interface, causing one to at first think you have to bleed the brakes, then after doing this several times I realized that the seals were no longer sealing properly. - I carefully measured the old seal, purchased replacements.  After carefully replacing the seals, they still leaked between the seal and the pistons.   (Even after a year +, I did not see any rebuild kits offered for sale.)
 
Regarding bleeding the calipers of all the air bubbles, I found this to be a very time consuming task on the first versions I have. Then they added an additional air purge hole in the second version.  (This helped a lot.)   I end up removing the caliper from the frame or fork, remove the pads, insatll a brake bleed spacer block, then I have to move the calipers in all sorts of directions, sometimes tapping on them to get all of the bubbles to come out.    Just flowing new fluid from the caliper to the levers, or levers through the calipers never worked for me.  The brakes would remain soft.

[ZacItaly15]

I can state that I am to the point that I can't recommend the IIIPro products anymore.   I have had 4 calipers fail  (I purchased 5 sets total of the IIIPro E4 brakes)
4 calipers having issues is too high of a percentage failure rate.   

The seals start leaking between the piston and seal interface, causing one to at first think you have to bleed the brakes, then after doing this several times I realized that the seals were no longer sealing properly. - I carefully measured the old seal, purchased replacements.  After carefully replacing the seals, they still leaked between the seal and the pistons.   (Even after a year +, I did not see any rebuild kits offered for sale.)
 
Regarding bleeding the calipers of all the air bubbles, I found this to be a very time consuming task on the first versions I have. Then they added an additional air purge hole in the second version.  (This helped a lot.)   I end up removing the caliper from the frame or fork, remove the pads, insatll a brake bleed spacer block, then I have to move the calipers in all sorts of directions, sometimes tapping on them to get all of the bubbles to come out.    Just flowing new fluid from the caliper to the levers, or levers through the calipers never worked for me.  The brakes would remain soft.

Thanks for your contribution. Can you share the correct replacement seal size in order to avoid purchasing wrong size?thanks

[Tijoe]

I purchased this seal, except these seals did not fix the problem of leaking between the piston OD and the seals.   Therefore I can't recommend these as the fix.

https://www.ebay.com/itm/186234831612