how to tell if vac pump is bad

[itsunday25]

i got a m1010 the trans went bad on me two times and its out again but i dont now if my vac pump is working right on my 7.3 you can hear it pumping when you take the hose when you do it on the 6.2 you cant hear it idk if eney one has info on thes or where i can get a trans that be great thanks.

 

[jdemaris]

i got a m1010 the trans went bad on me two times and its out again but i dont now if my vac pump is working right on my 7.3 you can hear it pumping when you take the hose when you do it on the 6.2 you cant hear it idk if eney one has info on thes or where i can get a trans that be great thanks.

It's a easy check. Just put a vacuum gauge on it, run the engine and see if it draws 21" of vacuum within 30 seconds. That's all there is to it. Note that is the proper reading at sea level. It will read lower, the higher your altitude. At 15,000 feet, it should read only 12" of vacuum.

CAV and Delphi used to sell replacement vacuum pod for $40. Just the pod with the diaphram - no need to change the whole pump.

You can also put a mechanical modulator on the TH400 trans and eliminate the need for the vacuum pump. That only works in trucks that do not need the vacuum pump for other accessories - e.g. cruise control, AC controls, etc.

 

[rnd-motorsports]

get a vac gauge and check if you find you need one look on maybe ebay or your local parts store a couple of part numbers for you are A-1 cardone ( rebuilt ) part # 641201 here about $70.00 + core about $5.00 or new AC Delco part# 215116 or Standard Motor Products part# vcp101 Here about $175.00 good luck!