I own a 1993 T100 4x4 which is experiencing a very strange problem. After the engine warms up the brakes start locking up. It appears that both the front and rear breaks are doing it since they all are hot to the touch. The brake pedal has hardly no play and is at the top. I have checked the brake fluid and it is not warm. The emergency brake is not draging. Once the engine cools down the brakes work fine.

Now to add to this, a small amount power steering fluid was also accidently added to the brake system. The brakes were bleed completely. And now have regular brake fluid in them.

This truck is rarely driven.

Any clues?