Chevrolet Repair: 2001 S-10 Blazer Shift solenoid, chevy blazer, vacuum leak

Question
Hi,
I have a 2001 Chevy Blazer 4WD. I've been having an intermittent problem with shifting. It seems like when the problem occurs it almost always hits at 1500 RPM, as soon as I touch the accelerator the RPMs drop like the gas is just cut off. I put it on a computer and it read as a vacuum leak and shift solenoid B is sticking. Could these issues be related? and Why does the bottom drop out when it won't shift? any ideas?  

Answer
Hi Scott Griffin,

The transmission is mostly computer controlled.  When any trans shifts, there is more than one things happening inside.  A band and a clutch will apply to achieve one gear, two bands and no clutch for another.  This type of thing.

When solenoid B doesn't work, some component is not applying when it needs to, and you achieve what feels like a wrong gear.  

Vacuum leak could be pointing toward the kickdown.  The kickdown on some Chevy is vacuum operated.  Without that, your truck won't shift correctly.  This is what tells the truck to downshift.  I believe your kickdown is not vacuum operated.  If not, then the vacuum leak may be pointing to a port vacuum leak.  At idle you have manifold vacuum.  At acceleration, man falls off and Port comes up.  Your transmission may be reading vacuum to give inputs to the computer about transmission correct gearing.  This could replace the vacuum operated kickdown.

C J S