I do not think that one could affect the other.
To check if a brake booster has failed, do the following;
Before starting the truck, pump the brake pedal till it is firm.
Next, keep your foot firmly pressed down on the brake and start your truck.
If the brake booster is OK, it will fall away under your foot and not be as firm.
Sounds wierd, but true.
The brake bosster uses vacuum to assist in decreasing the amount off pedal pressure it takes to stop the truck, thusly the drop in the pedal when starting your truck.
Some trucks do use air brakes and some off roaders even use hydrulically pressurized systems that us a pump just like a power steering pump. You can look at the bosster on your truck and see a vacuum line, about 1/2 in diameter or less, that leads to the manifold or some vacuum source.
If you are running big tires or carry heavy loads, power steering racks and pumps can wear out more quickly from the extra stress.
Check the power steering fluid.
Is it burnt or a dirty brown color?
Does it smell burnt?
Let me know how things go and I will check back to see what the fluid is looking like.
If your experiencing steering issues, it is probably the pump or rack. I will help all I can to get it figured out.
Saturday, October 9th, 2010 AT 2:10 PM