hi scrod i have a brake to brake lever question:

so i have some older but aero shimano 600 brake levers. no springs however. i dont think these ones came with them...

anywho i installed one to the front brake, an ultegra.
the lever return seems...clammy. like when you actuate it, it seems to be slow on the return. no me gusta.

its a new cable, and i've used a synthetic lubricant on all joints of the lever and brake. i would figure the brake lever itself would be spring enough to return the lever to position quickly.

any ideas?
or should i just bite the bullet and buy some newer, spring return brake levers?