Fjs 600 front brake issue

Need a bit of advice folks. I had a good front brake but found pads were very worn so I replaced them with (in hindsight not a good move) cheaper version pads.
Now I have a spongy soft brake that I can not cure I have bled them numerous times to no avail.
I have replaced the seals in the front leaver cylinder.
Have changed the pistons and seals in the calliper, but still soft and spongy. The rotor is in good shape and there are no fluid leaks to be found.
I know it sounds a bit daft but could it be down to using cheap pads? I would not of thought so but its the only explanation left open to me as the brake went soft as soon as I just replaced the pads.
Has anyone else experienced a similar problem.

SWAG, trapped air, have you bled the complete system in the correct order? too you might just get away with tying both brake levers back and leave it overnight to see if that helps. Who's brand pads? not likely they alone are your problem.

Thanks for the reply, yes have done all that including tying the levers back. just seems strange that I only got a soft brake after I changed the pads only and did not do anything else to the brakes.

Hmm did you clean the pistons, and a 2nd thought, a rubber brake line with a soft / bad area bulging.

The Swing uses a sliding caliper arrangement; if the caliper cannot slide freely on the pins then it will flex sideways and give a spongy feel. When you changed pads and pushed the pistons back, the caliper will also need to move on the slide pins by the same amount as the total increase in pad width. I would certainly check that the caliper is free to slide on those pins, they should be lubricated with silicone paste to keep the rubber parts healthy.

Another possibility is if you have caught the edge of the pad spring on the new pads and wedged it sideways. I did that once on my VFR back brake and it produced a really spongy brake with no power, even though it was well bled.

Thanks for the info, when I had the calliper off I had it all stripped cleaned and lubricated and the calliper does move freely. I am going to remove the calliper and check that I have not caught the pad spring and make sure the pads are seating as they should.

Terry, my first thoughts exactly! Caliper movement is crucial and it gets crudded-up more often than you might think.

Also, pad seating can be a frustrating experience, no matter how many times you do it

Thanks Loosemarbles I have had the calliper off again made sure that everything is as it should be and refitted the pads but this time I have omitted the pad shims that were originally on the previous pads but I fitted them as my new pads came without them. I must say the front brake is much better although not perfect but hope it settles down a bit when I have done some miles.

The other thought I had was around the fit between an old disc and a new pad. My old discs did not wear flat, they were dished a little. A new flat pad only makes contact on the high spots and not at the bottom of the dish, which means the friction generated is substantially less. That also means to get decent braking power you have to squeeze much harder on the new pad than you may have on the old, and that makes the brake feel more flexy. In a fairly short order, the pad will wear into the disc and conform to its shape, and you will be back to full brake power again.

Cheers for that Terry I was thinking of that possibility