I've owned a zetor 6245 for 25 years and am trying to dismantle the left hand wheel portal. I'am having trouble removing the brake shoe holder from the rear axle bushing. The six M10 bolts have been removed and I've made a puller to apply pressure to the brake shoe holder. After applying wd40 and many attempts the brake shoe holder has moved only approx 5mm. Has anybody had this problem or have a solution to my difficulty?