Continuation: IIIPRO E4 4-Piston Hydraulic MTB Brakes - Are they to be trusted?

[Tijoe]

   
Since the original thread is over 120 days old, this is new thread regarding these IIIPRO brakes and my experience with them.

Existing thread:  https://chinertown.com/index.php?topic=4049.0

My conclusion after almost 2 years of usage!  No they are not to be trusted.  My trust in them being reliable and safe is gone!!!

Yesterday I finished riding a 300 mile multi-day bike-camping ride.  32K up and 32K descending.   About 100 miles into the ride, the rear brake started losing pressure.  I had to start pumping up the brakes by rapid-pulsing of the rear lever.   This made descending steep sections of slippery gravel roads a challenge.   This is the 5th 4-piston IIIPro caliper that failed, and the front caliper on the same bike is starting to have the same problem.   (FYI, My brother, who I talked into purchasing a set suffered the same failure on one of his calipers.)

After trying, unsuccessfully!, to rebuild my first pair of calipers, failed, this caliper will join 4 others in the "failed parts" bin.     

Every caliper that has failed, appears to start sucking in small amounts of air between the seals and the piston/body.   Over time I can start to see a small amount of air bubbles coming out of the seals when the calipers are activated on the bench.  When too much air works it way into the calipers they loose pressure.   

I really am Pissed off about this overall. 

I will try one more time to try to work with IIIPRO to figure out if any of the calipers can be repaired and trusted to use again!

https://www.aliexpress.us/item/3256804577690212.html

[frnchy]

Fool me once, shame on you.
Fool me twice, shame on me.

Fool me six times….

Just buy some cheap Shimano brakes, or if you’re hauling heavy loads on a flat bar bike routinely, bite the bullet and invest in some Mavens. Unlike a lot of other components, brakes are an area where Chinese products are not up to par with established brands (not even necessarily western ones; TRP is Taiwanese and they make good brakes too).

[Serge_K]

Can you please explain the thought process of buying the same product 6 times? I'm not making fun, I really do wonder how you justified giving the same product another chance, then another, then another, then another, then another?
We have been running ltwoo er9 on five bikes and all but one derailleurs died once, but no derailleur has died a second time, and it was across five bikes.

Also, it's a bummer, because the calipers look similar to the road version that came out recently as reviewed by trace vélo. And I'm tempted.

[bremerradkurier]

The current AliX price doesn't seem all that great compared to the seemingly identical Clarks branded brakes.

[urlhttps://www.merlincycles.com/en-us/clarks-crs-c4-cnc-4-piston-hydraulic-disc-brake-set-295294.htmlurl]

[Tijoe]

Can you please explain the thought process of buying the same product 6 times? I'm not making fun, I really do wonder how you justified giving the same product another chance, then another, then another, then another, then another?
We have been running ltwoo er9 on five bikes and all but one derailleurs died once, but no derailleur has died a second time, and it was across five bikes.

Also, it's a bummer, because the calipers look similar to the road version that came out recently as reviewed by trace vélo. And I'm tempted.

Actually, I have "4 sets" of the IIIPros, and one set of the 4-piston Bucklos brakes.  (Bucklos = parent company of IIIPro.)

I purchased the IIIPro brakes "2-sets" at a time during Aliexpress sales, about 6 months apart, before I started having problems with the calipers.   (Purchased 3 sets for bikes I built, and a spare set.)
Based on the initial reviews 1-1/2 to 2 years ago, they appeared to be a good modulated feeling lightweight  great brake for the price.   -  They have performed very well overall, but appear to have a short seal life.
 
When I think about the bike that the calipers are failing on,  it appears that on this bike,  I do a lot of  heavy duty long downhill braking, at high speeds, and this is where the calipers don't last.   This is my hardtail that doubles as a bike camping/bikepacker.  I am guessing that heat build-up in the calipers is doing something to the seals.

Since I started this thread, I wrote Bucklos explaining the situation, and to ask if they have a seal kit, versus me purchasing replacement seals based on digital caliper measurements and what I could find online for sale.   

I've had my fair share of premature leaky seal failures on my XT calipers over the years,  so having seal failures on the IIIPros isn't too big of a surprise.

What I would like to know is if IIIPro is using a crappy seal material, or if they have a design flaw in the calipers leading to short seal life.   (When I look at the design of the caliper bore that the seals and pistons fit into, they visually look the same as all the other calipers I have rebuilt over the years.   
of the leaky calipers. I see no signs of wear on the bores or pistons.