I need to bleed my 705 brakes. I bought what is supposed to be a Shimano compatible MTB bleed bowl with adapters, but none of them seem to fit. The narrow one looks about right but a bit short, and the threads don't engage. Anyone any ideas what adapters or bleed kits I need to get?

I measured the port screw and the plastic adapter that came with EZmtb base kit. They are both M5 and the thread pitch looks the same. I can only assume that the plastic adapter is slightly undersized. I notice in the Wisper how to video, the mechanic uses a bleed bowl with a metal adapter.

I've ordered a metal bleed cup/funnel/bowl from Total Bleed Solutions who are UK based.

Nearly all hydraulic bicycle brakes are self-bleeding. You don't need any bleeding kits. Just position the bike so that the hose goes generally uphill from the caliper and pump the lever until the air has come out.

My wife needed to adjust the reach on her 705 ?

 

https://www.pedelecs.co.uk/forum/threads/wisper-705.46055/post-691468

The metal bleed cup fitted perfectly, so both brakes bled at the lever and the sponginess has gone. I also increased the lever reach.

Nearly all hydraulic bicycle brakes are self-bleeding. You don't need any bleeding kits. Just position the bike so that the hose goes generally uphill from the caliper and pump the lever until the air has come out.

 

Where does the air come out? Do you take the lid off the master cylinder reservoir?

Where does the air come out? Do you take the lid off the master cylinder reservoir?

There's no need to take the lid off the reservoir because the volume in the system doesn't change; however, what I've noticed is that the more air is in the reservoir, the higher the chance of air going into the hose when you invert the bike. On the other hand, if you fill the rervoir to the top, then start riding your bike, the heat from the brake expands the oil, and it can make your brake jam on permanently until you let some oil out. That's why cars and motorbikes have that rubber bellows thing in there, but I haven't seen one in a bike brake, though it doesn't mean they're all like that.

There's no need to take the lid off the reservoir because the volume in the system doesn't change; however, what I've noticed is that the more air is in the reservoir, the higher the chance of air going into the hose when you invert the bike. On the other hand, if you fill the rervoir to the top, then start riding your bike, the heat from the brake expands the oil, and it can make your brake jam on permanently until you le

 

Please forgive my thickness but where does the air come out then, when you pump the lever? Do you open the bleed screw on the caliper? Or does it rise to the surface inside the reservoir?

Please forgive my thickness but where does the air come out then, when you pump the lever? Do you open the bleed screw on the caliper? Or does it rise to the surface inside the reservoir?

No air can get into the system, except when you turn the bike upside dow, in which case a bubble gets into the hose and makes the brakes spongy. When you turn the bike up the other way, you pull the lever about ten times, and you feel it gradually becoming firmer as the air bubbles back into the reservoir and sits above the surface until the lever is firm again. I have had a couple of times when the air couldn't easily get back out because it was trapped further down the hose. In that case, I just tilted the bike so that it was uphill all the way up the hose. Air always tries to go upwards.

No air can get into the system, except when you turn the bike upside dow, in which case a bubble gets into the hose and makes the brakes spongy. When you turn the bike up the other way, you pull the lever about ten times, and you feel it gradually becoming firmer as the air bubbles back into the reservoir and sits above the surface until the lever is firm again. I have had a couple of times when the air couldn't easily get back out because it was trapped further down the hose. In that case, I just tilted the bike so that it was uphill all the way up the hose. Air always tries to go upwards.

 

Good to know, thanks.

 

So I guess the only time one would need a bleed kit would be if you wanted to replace all the fluid or build a brake from scratch from separate components.

 

Apologies for the thread hijack OP.

Air space in the reservoir increases as the brake pad wear increases, unless one lays a bike on it's side or upturns it then air shouldn't be an issue.

Good to know, thanks.

 

So I guess the only time one would need a bleed kit would be if you wanted to replace all the fluid or build a brake from scratch from separate components.

 

Apologies for the thread hijack OP.

You don't need a bleed kit at all for most bicycle hydraulic brakes. I've replaced calipers and hoses, and I never needed one. Air always tries to go up in oil, so just hold everything so that the only way is up.

 

You never need to replace the brake fluid either. That's a scam when they do it to your car or motorbike. They tell you that the oil can absorb moisture, but the system is completely sealed. There's nowhere for the moisture to come from unless you open the reservoir every day to check something. My motorbike was 20 years old with 40, 000 miles and never had anything done to the coolant or brake fluid. Everything worked perfectly, especially the brakes. It had only done 1100 miles when I bought it, so all servicing was done by me. All it ever needed was engine oil and filter change, brake pads, occasional light bulb, tyres and occasional lube on the choke cable.

You don't need a bleed kit at all for most bicycle hydraulic brakes. I've replaced calipers and hoses, and I never needed one. Air always tries to go up in oil, so just hold everything so that the only way is up.

 

You never need to replace the brake fluid either. That's a scam when they do it to your car or motorbike. They tell you that the oil can absorb moisture, but the system is completely sealed. There's nowhere for the moisture to come from unless you open the reservoir every day to check something. My motorbike was 20 years old with 40, 000 miles and never had anything done to the coolant or brake fluid. Everything worked perfectly, especially the brakes. It had only done 1100 miles when I bought it, so all servicing was done by me. All it ever needed was engine oil and filter change, brake pads, occasional light bulb, tyres and occasional lube on the choke cable.

 

I learn something new every day on this forum.

 

I remember years ago, me and my mate fitted a complete new front brake on his Suzuki GSX600 . All the components were dry and needed filling with hydraulic fluid.

We naturally assumed we'd just have to fill the reservoir, open the bleed screw on the caliper and pump it through.

But it didn't work, the fluid refused to budge no matter how much we pumped the lever.

A quick trip to our local motorbike shop and had a chat with a mechanic. He said we were filling it from the wrong end, he suggested we get a big syringe and pump the fluid into the brake from the caliper bleed hole and up into the reservoir until you got to the right level. It worked, once the brake components are filled with fluid you can bleed it to your heart's content.

 

Of course with pushbikes one simply buys the complete brake system pre-filled with fluid, just shove it on the bike, tighten three screws, job done.

I had the same issues and can confirm that the Total Bleed Solutions metal funnel fits the 705

I had the same issues and can confirm that the Total Bleed Solutions metal funnel fits the 705

You don't need to bleed most ebike hydraulic brakes.

Needed to add an extra oring (took from plastic funnel) otherwise it dripped

You don't need to bleed most ebike hydraulic brakes.

 

This is of course complete boolocks. Brakes need bled if they become spongy, and turning a bike upside down does not introduce air into the system.

 

Really Saneagle, you do come up with the most bizarre notions sometimes.

 

I've bled brakes for decades, people i know have bled brakes for decades, watched dozens of bike mechanics at races bleeding brakes. All pro's, all working for big companies.

Are you trying to say all of them have been hoodwinked and dont know what they're doing.

 

System is sealed. but its not sealed 100% air can get drawn in and can affect the fluid by Adsorption, rather than absorption.

 

And ive also serviced brakes that have been lying for years. - used to buy old bike brakes, strip and service and resell. and the fluid on old brakes can be manky and emulsified

This is of course complete boolocks. Brakes need bled if they become spongy, and turning a bike upside down does not introduce air into the system.

 

Really Saneagle, you do come up with the most bizarre notions sometimes.

 

I've bled brakes for decades, people i know have bled brakes for decades, watched dozens of bike mechanics at races bleeding brakes. All pro's, all working for big companies.

Are you trying to say all of them have been hoodwinked and dont know what they're doing.

 

System is sealed. but its not sealed 100% air can get drawn in and can affect the fluid by Adsorption, rather than absorption.

 

And ive also serviced brakes that have been lying for years. - used to buy old bike brakes, strip and service and resell. and the fluid on old brakes can be manky and emulsified

Ebike ones don't. They're nearly all self- bleeding. Yes you have been hoodwinked. I have installed many hydraulic brakes, and I've serviced many, both for myself and when I worked as an ebike mechanic for 2 1/2 years. I've never had to bleed any yet.

 

The brake fluid should never go emulsified because the fluid system is completely sealed. No air can get in unless you've done something wrong. The only time you'd get problems is when people mess about with it when they don't know what they're doing.

 

When you turn the bike upside down, any air in the reservoir will go into the hose unless the reservoir has a rubber bellows. That's why brakes can go spongy afterwards until you pump the lever a few times to operate the self-bleeding. The bellows separates the air from the fluid.

 

Many people have asked about their spongy brakes on this forum during the 14 years I've been on it. I always explain how to self-bleed them, then they come back and say thanks, it worked. Not one has ever come back and said it didn't.

Edited May 29, 20241 yr by saneagle

I have never needed to use a bleed kit on bicycle hydraulic brakes. There’s not much fluid in there and I’ve always pumped the air out using the lever.

 

I have done this on Tektro, Clarke, Risun and Talaria. None of them needed a bleed kit.

My brakes were completely dead, front and back. Maybe the many times I had to turn it upside down to fix something didn't help, but most likely due to 18months it spent behind boxes at the back of my shed after we moved house was the main reason.

My brakes were completely dead, front and back. Maybe the many times I had to turn it upside down to fix something didn't help, but most likely due to 18months it spent behind boxes at the back of my shed after we moved house was the main reason.

You just hold the bike in such a position that it's continuously uphill from the caliper to the brake reservoir and pump the lever a few times to restore the brake function.

I tried that several times for quite a few minutes each time, I tapped and shook the cables - nothing!

The front brake is naturally directly below the lever, no high spots to trap bubbles. The back is more awkward. Even the 'simple' bleed (just a bowl on the lever bleed point) didn't work (I had a stand by then) , I had to inject from the caliper and it was full of bubbles.

 

Maybe Wisper keep the 705 cost down by not fitting self bleeding brakes: they are unbranded (unlike the derailleur and other parts) and Wisper actually have a video tutorial showing you how to bleed them.

I tried that several times for quite a few minutes each time, I tapped and shook the cables - nothing!

The front brake is naturally directly below the lever, no high spots to trap bubbles. The back is more awkward. Even the 'simple' bleed (just a bowl on the lever bleed point) didn't work (I had a stand by then) , I had to inject from the caliper and it was full of bubbles.

 

Maybe Wisper keep the 705 cost down by not fitting self bleeding brakes: they are unbranded (unlike the derailleur and other parts) and Wisper actually have a video tutorial showing you how to bleed them.

The only way that can happen is if you had a fluid leak or your reservoir wasn't filled properly. Self bleeding doesn7work if the fluid level is below the hole where it goes through to the piston. That can happen when the reservoir isn't filled enough and you have an extreme horizontal angle of the reservoir that you can get on some handlebars.

I tried that several times for quite a few minutes each time, I tapped and shook the cables - nothing!

The front brake is naturally directly below the lever, no high spots to trap bubbles. The back is more awkward. Even the 'simple' bleed (just a bowl on the lever bleed point) didn't work (I had a stand by then) , I had to inject from the caliper and it was full of bubbles.

 

Maybe Wisper keep the 705 cost down by not fitting self bleeding brakes: they are unbranded (unlike the derailleur and other parts) and Wisper actually have a video tutorial showing you how to bleed them.

 

There is no such thing as 'self bleeding brakes' its a complete fantasy.

 

Marshy will show you how. marshy is a professional bike mechanic with a manufacturer team and the bike mechanic for Greg Minnaar

 

'Pumping' the levers does not drive the air out, nor does it bring it to the master cylinder reservoir. To get the air out you must bleed them.

 

But according to 'someone' here Jason 'Marshy' Marsh is wrong, 4 time World cup DH champion Greg Minnaar is wrong, Team Santa Cruz is wrong, every professional bike team in the world along with their professional and certified mechanics are wrong, and only that 'someone' is right.

 

They've all been "Hoodwinked" you see

 

Brakes are really important,and its the only thing keeping you out a wheelchair or worse.