K3500 hydraulic brake booster engages brakes when

there is no connect between brakes and steering so for the present pass on the booster idea
when the wheels are no turning ( like when stationary) the steering is normally hard to turn as there needs to be movement for the rubber to move on the road ( old manual boxes were well known for this)
I suggest that the power steering is low on pressure and because you notice it more under brakes I would have the power steering pressure tested by an accredited steering specialist shop

has the front suspension been checked? binding? seized ball joint?

I think I would get the body computer scanned for trouble codes and find out why the ABS warning light is on first.
The hissing noise usually means the booster is leaking vac but if the booster was faulty the brake pedal would be hard to push.

Brake and clutch are vacumme assisted and hard to start seems like vac hose left of of has leak

Why lol? Whats the issue? Does it have a brake booster or hydraulic pump?

are you talking about brake fluid --power steering lines do not connect to the brake system --- also their is no weep hole at the bottom of the brake booster ---can you please clarify what is leaking and where --power steering lines from pump to radiator to steering rack ----brake booster mounted to fire wall with brake master cylinder bolted to front

Hi, you are right the rear is for the rear,the best thing is to pull both rear wheels off and remove drums that way you are looking at the wheel cylinder and then you will know if that is your problem,some times when they leak you cant see it with out pulling drums off. If no problem there check around master cylinder for leaks and around brake booster inside truck. Then if you still have no sign of fluid take the two nuts off master cylinder and see if leak is in side booster is wet.
If need more info please re post.
Thanks dodge tec

YOUR VECHICLE HAS THE HYDRALIC BOOSTER.WHICH YOU POWER STEERING PUMP CONTROL BRAKING SYSTEM.CHECK POWER STEERING PUMP FLIUD LEVEL.IF LOW CHECK POWER STEERING PUMP HOSES FOR LEAKS.IF YOU FIND NO LEAKS.THE HYDRALIC BOOSTER OR POWER STEERING PUMP FAULTY.

Does it have a hydroboost brake booster? Is the belt still on the p/s pump? Have you checked the power steering fluid level? If yes and good to all, replace the Power steering Pump.

Hi Salmancasmi,
On vehicles with a hydraulic booster you will find that the power steering pump supplies fluid through bot the steering gear box and the hydraulic booster.
Just a visual inspection of the system should point you to the part that failed, most likely a hose. These can be obtained through your local parts store or dealership.
Locate and replace the failed part, refill the reservoir with power steering fluid. With the front of the truck on jack stands, start the truck and turn the steering wheel from full left to full right several times while pumping the brakes. This will remove the air from the system. Recheck for leaks and fluid level and you'll be on your way.
Hope that helps, good luck.