My 94 GMC 6.5L TD has no vacuum pump. I know its purpose is to drive the turbo waste gate solonoid but what other functions does it operate in the truck. Is it really necessary ??

 

Your HVAC system work ok??

 

Most parts of the HVAC works. The fan only runs on high setting but the vac pump has nothing to do with the fan. I have a clacking sound in the heater area which was the subject of one of my previous threads. I suspect that a heater shutter might be driven with vacuum but I don't know for sure and haven't been able to find out for sure. Any clues there??

 

HVAC does not work off vacuum the Vacuum pump run the waste gate and EGR system whit your yr of truck

 

My truck doesn't have an egr. The port on the top of the intake manifold has a plate on it.

 

maybe some all ready did way with it and if you have home made TM then you don't need it

 

What is 'TM'

 

Turbo Master that is where you get rid of vacuum pump and add the TM

 

I never heard about Turbo Master. After I bought the truck I found parts of the vac pump laying in the radiator shroud. It had broken off. The belt system works as is but might have been replaced after the vac pump broke off. So what does the turbomaster system do??

 

Turbomaster is a mechanical waste gate/boost control, made by Heath diesel. You can make your own using a spring and rod etc. When you remove the vac pump I think you would need a shorter serpentine belt.