Bleeding Hydraulic Brakes?

[Slick]

I've bleed my shimano 105 brakes as per the usual suspects videos on YouTube, I even repeated the process to ensure there was no stubborn air pockets, I then made the mistake of reading the instructions that came with the kit and I started following them before totally confusing myself so I started again from scratch but there was zero air 3rd time out and I just ended up swapping oil.

My brakes now work but there is still a lot of travel in the lever and I thought the bleeding would have solved that so I suppose my question is, can I adjust the lever to reduce the travel to the bite point or has something else went wrong with the bleeding operations?

 

[ozboz]

I've bleed my shimano 105 brakes as per the usual suspects videos on YouTube, I even repeated the process to ensure there was no stubborn air pockets, I then made the mistake of reading the instructions that came with the kit and I started following them before totally confusing myself so I started again from scratch but there was zero air 3rd time out and I just ended up swapping oil.

My brakes now work but there is still a lot of travel in the lever and I thought the bleeding would have solved that so I suppose my question is, can I adjust the lever to reduce the travel to the bite point or has something else went wrong with the bleeding operations?

I’m not sure about all brakes , my Shimano XT have an adjusting screw a on the lever to take up the slack ,

 

[si_c]

Shimano 105 levers have a lot of movement in them I have the same set (R7020) and the lever pulls almost to the bars. You could try using a thinner bleed block as that would allow the pistons to move out slightly, but it's a bit of a bodge.

Alternatively get the R8020 lever set which does have bite point adjustment, but it's a lot to spend just for that.

 

[Slick]

I’m not sure about all brakes , my Shimano XT have an adjusting screw a on the lever to take up the slack ,

I've adjusted the screw at the side but no avail unfortunately.

 

[Slick]

Shimano 105 levers have a lot of movement in them I have the same set (R7020) and the lever pulls almost to the bars. You could try using a thinner bleed block as that would allow the pistons to move out slightly, but it's a bit of a bodge.

Alternatively get the R8020 lever set which does have bite point adjustment, but it's a lot to spend just for that.

Nah, don't fancy a bodge or spending money as they are already an upgrade, but thanks for the tip. I put another bike in for a service and I was trying to emulate the results he got but nowhere near. If that's the way they are meant to be then fair enough, I may have to learn to live with them.

 

[Slick]

Should have known as brakes were fine one ride out then hitting the bars next ride out and I wrongly assumed they just needed bled. I again wrongly assumed that I did a poor job when I bled them and there was no change and when I investigated I eventually realised the real problem, seals on the front caliper are leaking. Ffs

 

[itboffin]

Take an elastic band and put it around the grip and brake lever leave it like that overnight and you should have less air and travel in the pull by the morning

 

[Slick]

Take an elastic band and put it around the grip and brake lever leave it like that overnight and you should have less air and travel in the pull by the morning

Sounds like a nice tip but bleeding wasn't the issue. The caliper leaked oil all over the rotor so it's a new caliper I'm needing. I'll keep the rubber band for another time though. 👍

 

[screenman]

Take an elastic band and put it around the grip and brake lever leave it like that overnight and you should have less air and travel in the pull by the morning

Could you explain how that works? I doubt it does and is just a passed about myth.

 

[Levo-Lon]

Could you explain how that works? I doubt it does and is just a passed about myth.

Helps shift trapped air, common fix on motorcycle brakes.

 

[Levo-Lon]

Another good fix for long lever travel is remove caliper.
Slide the caliper so it's just about off the disc.
Pad edge just on disc 1-2mm ,pull lever and then release don't allow it to come off.
Push caliper back on and adjust and tighten.

Hopefully a good short travel lever will result

 

[screenman]

Helps shift trapped air, common fix on motorcycle brakes.

No I asked why it works, I do not think it does. Your second idea maybe in fact the first idea could be what is happening the same. Compressing air in a hydraulic line does not make is go away.

 

[Levo-Lon]

No I asked why it works, I do not think it does. Your second idea maybe in fact the first idea could be what is happening the same. Compressing air in a hydraulic line does not make is go away.

No it doesn't make it go away,what it does is help it rise to the master cylinder ,so it leaves the pressure side of the system.
Air in a brake line causes the springy long travel as does too big a pad gap.
Which you obviously know @screenman

Another common mistake people make when bleeding as system is thinking all the air should be pumped out the bleed nipple.

Often simply moving the master cylinder lever on a bike a few mm a few times let's the bubbles back up in to the master cylinder.


a modern complex car system is very different as this requires a machine due to ABS

 

[screenman]

No it doesn't make it go away,what it does is help it rise to the master cylinder ,so it leaves the pressure side of the system.
Air in a brake line causes the springy long travel as does too big a pad gap.
Which you obviously know @screenman

Another common mistake people make when bleeding as system is thinking all the air should be pumped out the bleed nipple.

Often simply moving the master cylinder lever on a bike a few mm a few times let's the bubbles back up in to the master cylinder.


a modern complex car system is very different as this requires a machine due to ABS

I bleed the brake system on many cars fitted with abs without the use of a machine, We are going to have to disagree on this one as I am of to play with fixing things with hydraulic brakes today.

 

[Levo-Lon]

I bleed the brake system on many cars fitted with abs without the use of a machine, We are going to have to disagree on this one as I am of to play with fixing things with hydraulic brakes today.

No prob