I have a 74 4x4 k5 blazer automatic transmission has been rebuilt about 20 years ago but with minimal miles since then it shifts up fine but wont shift down unless you manually put it in first then back into drive WHAT MIGHT B THE PROBLEM??

 

Is the kick down cable (a.k.a. TV or Throttle Valve cable) connected to the carb?

Also, is the vacuum line connected to both full intake manifold vacuum source on the engine as well as the modulator on the transmission?

 

I will have to check that

 

If you need visual assistance, just let me know and I will snap some pictures of the areas of interest on my '74.

 

Please do show me some pictures I am going to try to fix it this weekend

 

I will try to remember to take some pictures when I get home from work this evening.

*EDIT* - Please find the annotated attachments below:

 

Thank you. I will try to check that out I'm not to mechanic Savvy but I will c what I can do with it

 

I looked at the vacuum module and the short piece of hose after the module looks like it has a pin size hole in it could this b the problem