Yet Another Vacuum System Thread

[Russell Brungard]

Hi guys, new OilBurners forum member here with my first post. Been lurking on this site for info for years but now that I am back into my IDI, I figured it was time to join for real. So anyways, I have an ‘83 F-250 regular cab, 8’ bed truck that’s been swapped from the 6.9 to the 7.3. After countless years of headaches and heartaches with a terrible vac system, and most recently my 7.3 PSD giving up the goods, a have ditched my vacuum brake booster and converted to hydroboost to get my old rig tractor towing ready. I know, old news to most right? Running a C6 transmission though, I’m still needing a control source for my trans. modulator. I have read lots about guys using the super duty style electric vacuum pumps after the HB conversion for their hvac doors etc, but info for C6’s in these trucks seems few and far between. So to get to the point, has anyone had experience with using an electric vacuum pump solely for the c6 (since I have manual hubs and cable driven hvac doors)? My VRV is currently still good and the modulator and hoses are all brand new, and I’m just not ready to shell out the money for the cable operated modulator. Any opinions, experiences, or input are greatly appreciated.

 

[Randy Bush]

Don't you still have the factory style vacuum pump, It should provide all the vacuum you need.

 

[Russell Brungard]

I do have it, however unfortunately the pump has failed for the 3rd time. I just replaced with a new unit about 3 1/2 weeks ago and it already pulls 0 vacuum at idle and only about 8inhg at full rpm. My upshifts are fine, but when you take your foot out of the accelerator, it downshifts sporadically on its own, due to the pump not producing any vacuum of course. Don’t get me wrong, I probably cheaped out a little more than I should have on the purchase, but like I said, this will be the 4th pump I’ve put on it in the last 6 years or so. I was just hoping maybe there was a better solution.


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[Scotty4]

Do you have a system leak? Any chance you've vacuum tested the system?

 

[Russell Brungard]

At this point the only thing in the system is the VRV, the modulator, and the hoses between them. Everything else has already been eliminated and I measured the vacuum my pump is pulling at the line from the pump before it hits the manifold on the firewall. So that pretty well roles out everything but the pump. Like I said, 0 inhg @ idle and about 8 inhg max at WOT.


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