I changed the master in my 1997 toyota 4 runner and bleed the brakes and master cyclider and the brake petal still is soft when I brake please help!

. Did you bleed brakes in this sequence: RR, LF, LR, and RF?

. Was your bleed technique good? Did you use a "one-man" bleeder? Harbor Freight has an inexpensive one-man bleeder (No. 98864) for $3.99. It has a one-way check valve. I use a similar product from Cal-Van.

Look for a load sensing valve at the rear axle and make sure it's bleed there too.
You also have 4 piston calipers and one of them may be seized causing irregular brake pad contact.

Did you bench bleed the master cylinder prior to installation?

Also, where did you purchase the master cylinder from? We had a customer get 3 different master cylinders for his Toyota truck from the same supplier and his brake pedal stayed spongy; we got him one through our supplier and the problem was fixed immediately.