Hydraulic brakes

[gazza81]

Pulled the mtb out this evening for a ride in the morning and the brakes are a little soft.
ive seen somewhere that you can cable tie the leavers overnight to get rid of some of the air.
Do i need to open the res cap or keep it closed?
Thanks

 

[fossyant]

Unless once you've given them a pump, I'd bleed them. It's not worth messing - it's the thing that stops you ! It's not like mechanical, if it's not working properly, fix it.

My Guide RS have been fab, only bled as they were the early models that would seize in hot temperatures - replaced the pistons. I bought my missus MTB from a fellow CC'er but he said the brakes were not working - Deore SLX - they just needed new pads and a bleed with new fluid.

If you've got a hydraulic system not working, you can't mess about. Bleed it. If that doesn't work then you have issues with the levers or callipers.

Full bleed. No 'bodge' - it's your teeth..... If that doesn't work, check each end (levers & calliper).

 

[gazza81]

I did do a bleed in the summer but its been sitting in the shed for a few months.

Just read somewhere about cable tieing the leavers can be good to get the firmness back

 

[fossyant]

Basically don't mess - you aren't riding tomorrow unless you fix them, or don't need them to work fully ! Ride up and down the road outside home with hard braking, just check. Hospital over Christmas and New Year is no fun (I know... got the badge - and your regular 'staff' are away too.... )

 

[fossyant]

I did do a bleed in the summer but its been sitting in the shed for a few months.

Just read somewhere about cable tieing the leavers can be good to get the firmness back

Get bike, quick brake lever pump. Check up and down outside house. Any loss of travel ? Don't get in this rubbish about cable tie the levers - why - if there is a fault, it would force more fluid out.

Go onto Epic Bleed Solution's web site and watch their video or download the instructions. It's easy..

 

[Levo-Lon]

Cable tieing a lever is for getting a stubborn air bubble out only.

I suspect you have a stiff piston.
Whip off the wheel and clean around the pistons and then get them moving
Force them back and pump out a few times, obviously put a pad spacer between the pistons for ease of retracting
Retry the lever

 

[Heltor Chasca]

Exact same issue with mine when left unused. Few little pumps and they are good to go.

 

[gazza81]

Well they felt a tad soft, i opened the res cap and pumped a few times, not sure why just thought that the air might need to escape somewhere, but since doing that they are even more soft!

A few pumps and they do harded up but left for literally 1 min or so and they are soft agian

 

[Gunk]

All you’ve done by opening the reservoir cap is let more air into the system. What you should have done first was to check the lever adjustment. My Sram Level TLM’s have a tiny Allen bolt which adjusts the levers, ideal once the pads have just started to wear a bit.

If you are not confident bleeding the brakes a competent bike shop will do it for around £20-30.

 

[Heltor Chasca]

Exact same issue with mine when left unused. Few little pumps and they are good to go.

For clarity: I do not open or adjust anything. Just pump!

 

[gazza81]

Yeah i realise now i shouldn't have haha
All part of learning i guess!

Any ideas how i can get them back again without doing another bleed?

 

[Levo-Lon]

Exposure to air via the cap doesn't cause air in the system.

Air in the system is from caliper or bleed screw ect.
Or low fluid.

Spongy brake from water " Dot 4 brake fluid hygroscopic" is another issue.
This water settles in the caliper and causes weak braking, especially when it gets hotter.

It maybe a case of incorrect fluid used? Mineral or dot? This would cause serious probs.
A correct system bleed processes should sort your brake if everything is good, i.e calipers are clean and all hoses and bleed points are good Correct fluid?

 

[gazza81]

Yeah defo correct fluid, mineral.

 

[Levo-Lon]

Yeah defo correct fluid, mineral.

Ok

Check pads are free, not sticking jammed in the caliper, check calipers work ok, then fluid leaks ect

 

[gazza81]

Literally all i done was open the cap and pump a few times ha
Should have just left them as they were!

Oh well, went for a ride anyway and i didnt die, they do work but have to give a good hard squeeze to lock the back wheel.

As its it's both brakes that have gone the same since opening the screw, i dont think it can be a seized caliper but when i have some time ill check them out