do you think your braking feeling is maybe an engine problem? In neutral hold the gas pedal a little to hold it steady just a hair over idle and see how it holds that rpm.

 

maby the transfercase switch is stuck and alowing vacuum to the front axle actuator and engaging the front axle. find the vacuum line going in under the battery tray and plug it. cut it if you want and get an adapter from the parts store to splice it back together only a few bucks. if you dont cut it you will have to route it all the way down to the top of the transfer case or take the battery out then take the tray out to get to it. this is a weird problem id like to know what it is if you figure it out. its kinda hard to tell you over the internet rather than actually being there and driving it.

 

Adding a bit to the confusion.

I have many many miles in 4WD LO/HI and offroad in my Blazer S10 1994.

Technically:
2 HI = Rear wheel drive through 4 speed automatic transmission throught transfer case to rear differential to wheels.
4 HI = Adds front wheels through transfer case which connects short drive shaft to front wheels via chain. (Method of changing, manual/electric is pretty much irrelevant because in either case the internals on the transfer case and front wheel drive are the same.)

NOTE: The S10 features NO differential in the transfer case. This is the cause for the stalling in idle when turning on pavements which have some friction, such as paved or a solid dirt road. It cannot equalize the different speeds between front and rear wheels. Sometimes when accelerating a bit you get a jumping sensation in the car when the wheels start to slip to force an equalization.

4 LO = Adds a reduction in the transfer case which is applied to the drivetrain rear-/forward. This doubles the torque and cuts revolutions to half (approximately). This means you need double the engine rpm to reach the same speed. At the same time the torque is doubled which means that the symptoms such as acceleration or the jumping and rubbing of tires on hard surface is more pronounced as well.

NOTE: This kind of 4x4 is not meant to be used on dry or hard surfaces with good grip and full turns at tight radii. I use my steering wheel on this kind of surface only for 3/4 of a turn and eventually back up to get around tight corners in order not to stress the drivetrain. On slippery surfaces it does a hell of a job because you always get torque to front and rear end. E.g. I had a Mercedes M standing still once because one of the rear wheels lost traction and because it has a central differential all the torque could take the one way to the spinning rear wheel. Not the case in an S10.

Because of the high rpm in 4LO required to drive the same speeds and a change in behaviour of the automatic transmission when releasing the accelerator pedal you have a strong braking sensation. It should be that way because it is designed to climb steep and descend steep without the need for braking in off-road driving.
I've been up 25 to 30 degree slopes in nearly idle. I've been up 45 degree (100 %) slopes - scary and down nearly as much without braking. The only pretty useless thing in offroading in the S10 is the ABS.

Hope that helps a bit of understanding to some of the behaviour described in this thread.

Somebody able to add more?

Good rides, Marc