Tektro hydraulic brake question

John F

Esteemed Pedelecer
Sep 3, 2013
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My brakes have a tiny screw which is used to adjust the brake lever to a sensible hand position.

Whilst my fairly recently replaced (original Tektro) disc pads are not wearing away rapidly as far as I can tell, why do I have to screw in this screw after almost every ride? The fluid has not been replaced since new (4000 miles ago) and it shows no sign of leaking at all. The brakes work perfectly in fact.

Am I missing soming?
 

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Nealh

Esteemed Pedelecer
Aug 7, 2014
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The lever should need no adjustment in such a short time.
If they use DOT 4 or5 fluid then it can break down and needs replacing other wise air has go it in if the travel is bad.
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
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Whilst my fairly recently replaced (original Tektro) disc pads are not wearing away rapidly as far as I can tell, why do I have to screw in this screw after almost every ride?
Maybe it's a bit loose in the thread hole and works its way out with use.

If it can be totally removed, take it out, put some medium strength thread locker on it, then screw back in to desired hand position. Allow time for thread locker to set.
 
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John F

Esteemed Pedelecer
Sep 3, 2013
435
55
The lever should need no adjustment in such a short time.
If they use DOT 4 or5 fluid then it can break down and needs replacing other wise air has go it in if the travel is bad.
The lever feels and performs just like it always did. It doesn't feel spongy either so unlikely air is present.

What is DOT 4 or 5? It just says mineral fluid
 

John F

Esteemed Pedelecer
Sep 3, 2013
435
55
Maybe it's a bit loose in the thread hole and works its way out with use.

If it can be totally removed, take it out, put some medium strength thread locker on it, then screw back in to desired hand position. Allow time for thread locker to set.
Yes that might make sense. I'll monitor the situation.
 

AndyBike

Esteemed Pedelecer
Nov 8, 2020
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If its the screw thing at the back of the lever in your pic thats what actuates the brake and is attached to the master cylinder piston, so you really want to leave that screwed where it is. Plus its only for reach adjustment and once set you dont need to readjust it . If the lever is moving closer to the bar you bleed the brake as its got air in it.
All hydraulic(and mineral oil) brakes need a fluid change and occasional bleeding to keep on top of regular maintenance.
What is DOT 4 or 5? It just says mineral fluid
What you need to remember is that swapping the two types of fluids can damage the brake system and is not recommended. Also, use only DOT 4 and DOT 5.1 brake fluid for Avid, Hayes, Hope and Formula hydraulic braking systems. Do not use DOT 5 brake fluid as it is silicone based and is not compatible with brake gaskets.
For Shimano, use Shimano Mineral Oil, for Magura, Royal Blood and for Tektro, Tektro Mineral Oil.
I think someones a wee bit mixed up there.

You can actually use car type mineral oil in tektro and shimano, and probably magura, and it is considerably cheaper option. LHM mineral oil is usually under a tenner a liter, shimano mineral oil is 30 quid a liter. It is pretty much the same thing and I've used it in shimano saint and xtr brakes without any issues.

Disc brakes are not wholly fit and forget. Sure, they last a very long time between services, but your fluid after some 4k miles is going to be pretty manky, and it should really be changed as a matter of regular servicing.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
20,138
8,231
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West Sx RH
The lever feels and performs just like it always did. It doesn't feel spongy either so unlikely air is present.

What is DOT 4 or 5? It just says mineral fluid
DOT spec fluid is used in cars etc and some push bike brake systems but increasingly mineral oil is used. DOT breaks down quicker then mineral.
 

John F

Esteemed Pedelecer
Sep 3, 2013
435
55
Maybe it's a bit loose in the thread hole and works its way out with use.

If it can be totally removed, take it out, put some medium strength thread locker on it, then screw back in to desired hand position. Allow time for thread locker to set.
Just tested on a 17 mile ride, and the little screw has unscrewed about 2 mm on the back brake, but not at all on the front brake, so you were correct!
 

Woosh

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May 19, 2012
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Just tested on a 17 mile ride, and the little screw has unscrewed about 2 mm on the back brake, but not at all on the front brake, so you were correct!
red threadlock will stop it moving for sure but I would suggest a drop of nail varnish may also work.