Help Bleeding Brakes

[steevwatson]

After riding my bike which was upgraded to hydraulic brakes bought from Big Game Bikes my girlfriend has decided she wanted to upgrade too. She loves a bargain and picked up a used set of Shimano brakes and levers from Gumtree for £20 they look like these ones on Ali express https://m.aliexpress.com/item/4000360416411.html?spm=a2g0n.orderlist-amp.item.4000360416411&aff_trace_key=&aff_platform=msite&m_page_id=1008amp-EJ3EV4lHhp5wtK1conrHvw1603886002833&browser_id=&is_c= they have the correct connector for the rad bikes too. I've installed the front brake and it works very well motor cut off etc all working. Now here's where I'm hoping you guys can help. The rear brake came with the hose detached from the lever as the seller had tried to feed the cable through his brake frame. So I've reattached the cable using a new insert and olive. The brake is obviously full of air and very spongy to the point it doesn't fully stop the rear wheel. I've got a bleed kit and I'm trying to bleed the brakes but for some reason I can't push oil into the caliper and when I try to bleed drain oil out no oil drains from the caliper. When I squeeze the leaver oil does flow out of the bleed nipple on the caliper but when I release the lever it is sucked back up the hose. I've tried following the instructions in this YouTube video but I'm now stumped. https://youtu.be/wYH9dvmZg-Q
Any ideas before I just put the stock brakes back on?

Sent from my Pixel 5 using Tapatalk

[spyder918]

Not sure what bleeding kit you have, but I have the Shimano one and I just bled my hydraulic brakes just fine.  Did you use the syringe to push oil through the line to the cup attached to the lever? 

[Mooree]

Recommend bleeding Shimano disc brakes without a bleed kit in case of bleeding brakes with a bleed kit can't work. Just remove your calipers and work on your bike's bleed port. Let the caliper hang to remove all air bubbles.