STR9170 Hydraulic Shifter Poor Spring Return

Discuss light weight issues concerning road bikes & parts.
ymisyd
Posts: 33
Joined: Mon Nov 20, 2017 12:16 am

by ymisyd

Hello,
My RH 9170 shifter has progressively been getting worse when it comes to the spring return. The left shifter "pings" back into the parked position but the RH one is very slow and doesn't have a positive spring return. This is causing the front pads to drag every time I brake. It's now got to the point where I'm manually pushing the shifter back to the parked position every time I brake.
I've cleaned and lubricated the front pistons but no difference.
Any help appreciated.

by Weenie


Vjl
Posts: 27
Joined: Wed Mar 16, 2011 7:14 pm

by Vjl

I can almost guarantee it's a lazy piston.

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Klaster_1
Posts: 775
Joined: Mon Aug 15, 2016 10:25 am
Location: Russia

by Klaster_1

Does it return if you push the pistons in? Did you check the lever tension spring?

TurboKoo
Posts: 537
Joined: Wed Oct 29, 2008 7:55 pm

by TurboKoo

I’ve seen few cases where thin film layer of J-KIT has not been “punctured” correctly and that has created restrictions on oil flow. Check that first from the caliber end. If possible cut hose just little and put new insert and olive.
Scott Foil
Shimano 9150
Shimano FCR-9100-P
Shimano C60 tubulars

ChiZ01
Posts: 311
Joined: Wed Jan 01, 2014 6:20 pm

by ChiZ01

I got the same issue with my 8070 lever, without anything connected the lever would fail to reset 20% of the time, feels like something is causing friction to the master cylinder piston, can i put lube into the piston?

ymisyd
Posts: 33
Joined: Mon Nov 20, 2017 12:16 am

by ymisyd

Vjl wrote:I can almost guarantee it's a lazy piston.
Thanks for the tip. Any advice on what to do to resolve this? I'm thinking of disconnecting the hose on Monday and starting with a fresh fill and bleed. This should at least give me an opportunity to make sure the shifter spring is ok.
Any other maintenance tips while I've got it all in bits? It's a self build and all the bits are only about seven months old.

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bikeguy0
Posts: 24
Joined: Mon Feb 18, 2013 6:01 am

by bikeguy0

I had same issue and had it warrantied. I rebled, cut hoses and new olives, and reoiled caliper piston seals and nothing worked.


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TonyM
Posts: 3259
Joined: Thu Jan 22, 2015 4:11 pm

by TonyM

ymisyd wrote:Hello,
My RH 9170 shifter has progressively been getting worse when it comes to the spring return. The left shifter "pings" back into the parked position but the RH one is very slow and doesn't have a positive spring return. This is causing the front pads to drag every time I brake. It's now got to the point where I'm manually pushing the shifter back to the parked position every time I brake.
I've cleaned and lubricated the front pistons but no difference.
Any help appreciated.
How old are they?
And how many km/miles with them?

ymisyd
Posts: 33
Joined: Mon Nov 20, 2017 12:16 am

by ymisyd

TonyM wrote:
Sat Jul 13, 2019 3:15 pm
ymisyd wrote:Hello,
My RH 9170 shifter has progressively been getting worse when it comes to the spring return. The left shifter "pings" back into the parked position but the RH one is very slow and doesn't have a positive spring return. This is causing the front pads to drag every time I brake. It's now got to the point where I'm manually pushing the shifter back to the parked position every time I brake.
I've cleaned and lubricated the front pistons but no difference.
Any help appreciated.
How old are they?
And how many km/miles with them?
Seven months old
2500 miles

ymisyd
Posts: 33
Joined: Mon Nov 20, 2017 12:16 am

by ymisyd

bikeguy0 wrote:
Sat Jul 13, 2019 2:53 pm
I had same issue and had it warrantied. I rebled, cut hoses and new olives, and reoiled caliper piston seals and nothing worked.


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Which part was replaced under warranty? Shifter or caliper?

bikeguy0
Posts: 24
Joined: Mon Feb 18, 2013 6:01 am

by bikeguy0

ymisyd wrote:
bikeguy0 wrote:
Sat Jul 13, 2019 2:53 pm
I had same issue and had it warrantied. I rebled, cut hoses and new olives, and reoiled caliper piston seals and nothing worked.


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Which part was replaced under warranty? Shifter or caliper?
Entire shifter.


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joren
Posts: 96
Joined: Tue Oct 31, 2006 11:26 am

by joren

same problem over here .

ymisyd
Posts: 33
Joined: Mon Nov 20, 2017 12:16 am

by ymisyd

So, today I bled the brake. A couple of tiny bubbles but nothing major.
I noticed, after researching, that everybody warns against operating the brake too much without pads in because the pistons will come out of the caliper. However, no matter how many times I pumped the lever, the pistons only ever came out about 3mm - no more.
Does this give any clues to the problem? After bleeding, the brake lever still won't spring back to the parked position. Is the caliper user serviceable? I can't find any documentation.
Thanks.

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Broady
Posts: 383
Joined: Thu Jan 03, 2013 5:02 pm

by Broady

Shifter warranty. Same thing happened to me, luckily was picked up before installing.

by Weenie


dricked
Posts: 184
Joined: Tue Jan 09, 2018 1:57 pm

by dricked

I too have this problem. I thought it was maybe some air trapped in the lever still but I guess not.

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