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View Full Version : Shimano GRX tamper proof bleed screw


chiasticon
02-20-2020, 06:34 AM
so I bought a Shimano GRX mini group recently. brand new take-offs. and I'm getting to the stage of setting up the brakes when I notice that the bleed screw is not the usual 2mm screw but instead a tamper proof torx. you know... the torx with the little pin in it? which I don't have any tools for so had to order some of those...

anyone ever seen this? is it possible Shimano made a running change to the screw they're using? none of their online docs mention it. I asked the seller and he said he never touched the shifters (which I believe, everything seems brand spanking new), he just removed the group to sell. but he did mention that they came off a Cervelo. so is it possible Cervelo replaced this screw while doing the build?

Black Dog
02-20-2020, 08:14 AM
Well, a bit costs a few dollars so easy fix for you. I bet they put that screw type to prevent endusers from accidentally removing it and compromising the brakes. A lawyer probably made the technical decision and not an engineer.

Hank Scorpio
02-20-2020, 09:20 AM
Unrelated question. Could you possibly post a picture of the lever with the hood rolled forward. I want to see the angle of exit of the hydraulic line compared to the R785 Ultegra.

chiasticon
02-20-2020, 10:27 AM
Well, a bit costs a few dollars so easy fix for you.yeah it's not the end of the world. just very confusing, especially for it being the first time I've ever tried to install/bleed hydro. but sounds like nobody else has run into this...

Mr Scorpion, I'll check ASAP. also... on your way out, if you want to kill somebody, it would help me a lot. ;)

chiasticon
02-21-2020, 05:17 PM
well I'm an idiot. the tamper proof torx screws are what holds the shifter together. there's one on the front of the shifter and right where the hydro line comes in, hence my confusion. anyway, the bleed port is still 2mm. I'm such a hydro newb! :help:

Hank Scorpio
02-21-2020, 09:56 PM
Thanks on both counts. I saw the Shimano installation guide and it does appear that it exits at a less severe angle than the R785.



“Oh, the Denver Broncos!”

chiasticon
02-22-2020, 01:36 AM
You just don't understand football, Marge.

Louis
02-22-2020, 01:55 AM
100 piece Security Bit Set

Maybe it's time for the OP to turn to a life of crime:

Link to Harbor Freight tool set (https://www.harborfreight.com/Security-Bit-Set-with-Case-100-Pc-68457.html?ccdenc=eyJjb2RlIjoiMjY5MjQ1NjEiLCJza3Ui OiI2ODQ1NyIsImlzIjoiNy45OSIsInByb2R1Y3RfaWQi%0D%0A OiI4NjE2In0%3D%0D%0A&cid=paid_google|||68457&utm_source=google&utm_medium=cpc&utm_campaign=&utm_content=&gclid=EAIaIQobChMI1I7Zvdbk5wIVAsNkCh0ZiwCmEAQYASAB EgKW7vD_BwE)

https://shop.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/6/8/68457_I.jpg

Blown Reek
02-22-2020, 07:24 AM
well I'm an idiot. the tamper proof torx screws are what holds the shifter together. there's one on the front of the shifter and right where the hydro line comes in, hence my confusion. anyway, the bleed port is still 2mm. I'm such a hydro newb! :help:

Ha! I found the exact same thing when I installed disc (Dura Ace r9120) for the first time. Being an old industry pro, I just called Shimano to find out when the design change and bolt specification happened. It turns out that bleed port is in a different location than it is on the Di2 shifter (I was following a 9170 YouTube install video), and once I discovered that, I too deemed myself as an idiot. You're in good company.