This is slightly off topic, but I figure many of you out there either have or had trucks with similar issues in the past and could potentially save me $ or time or both. I have a 98 Chevy dually and drive it pretty often ( I just bought this truck 4 months ago to keep from destroying my 04 F350). The truck drives and stops fine, but noticed this past weekend that when it had a load ( pulling about 8000 lbs) the truck didn't stop right. The brake pedal would almost touch the floor on hard stops and would only give 60-70 stopping force. After cleaning my pants (jk) I decided I need to investigate. Without a load no issues, but I pushed the pedal this morning while stopped and found I could push it almost to the floor and I hear some whining from the power steering pump. I drove it and it stops fine. So here is my question. Could it be the power brake booster? Is it the power steering pump? Could it be both, if so which one would you change first? Thanks in advance for any and all the ideas that you have. I don't really dig the idea of taking to the shop and paying double although I will instead of smashing into the back of some little old lady. I just bought a used dump trailer with a 15,000 lb capacity and while it has electric brakes, I need all the stopping power I can get.