Vacuum Pump delete Question...

[knkreb]

Well, the vacuum pump is no good in the burb. It has a little in and out pulsation on the vacuum line. Since it's an 'F' engine, I think we can do away with the extra stuff that is driven or fail at the worst possible moment.

In reading about the vacuum pump delete, I take it that there is no "dumby pulley" needed in it's place? A/C compressor is drivers side, vacuum pump is passenger side.

I saw the belt length differences, but nothing about if anything goes in place of it.

 

[Acesneights1]

I have heard people complain of belt chirp and premature belt failure. I left my Pump in place even though I have an F with a TM. Take a good look at the way the belt wraps around the pulleys and how it would be with no pump.
I'm sure others will chime in otherwise but that was my opinion. I would eventually like to build a delete pulley setup but to me it looks like the geometry is all off when you remove the pump.

 

[knkreb]

It looks like you need that pulley to help fold back the belt to give more crank pulley coverage....

 

[Acesneights1]

Exactly....
Some remove it but I wouldn't. JMHO.

 

[Acesneights1]

when time allows I want to look through the four season book and see if I can find an idler that would be close in size and then fab a mount for it.

 

[Green Machine]

I'm not sure on the 96+ setups, but on my 95 there isn't that much crank pulley surface area difference on the belt. Maybe 1/2" or so less? I'm doing this from memory... so I'm not 100% sure. I am also a few hundred miles from my truck so I can't go out and look either lol.

 

[ak diesel driver]

no problems with my delete

 

[matuva]

No problem either and my previous 1996. Just deleted the vac pump and replaced the stock belt with a 99.5" one.
Don't buy the squealing Dayco, take a Gates or else, but not Dayco : before I suspect a brand new Dayco belt to squeal, I replaced the tensioner and the alternator :mad2:

 

[bison]

works fine on my 98 as well,vac pump gone,just shorter belt.

 

[Paveltolz]

New alternator about a year before the vac delete and no chirping or other issues with my 96 either.

 

[iamdave0887]

No issues here on my 96 with my vac pump delete. It's been roughly 35,000 miles since i deleted it.

 

[Turbine Doc]

No vac pumps on either of my vehicles Kevin,

 

[Chief915]

No problems here either. The 99.5 inch belt was too short for my truck even with the vac pump gone, it wouldn't even come close to going on. A 100.5" belt is what I needed.

 

[GM Guy]

so the 99.5" belt is what you install for all vac pump delete situations, or is it just installed on 96+ trucks that have the pump deleted?

 

[Steve93mustanglx]

love my vac delete. 1 less thing to fail. But don't do it for MPGs... havent seen any improvement there.

 

[Turbine Doc]

so the 99.5" belt is what you install for all vac pump delete situations, or is it just installed on 96+ trucks that have the pump deleted?

Generically when you do a vac pump delete it's 1" shorter than the OEM one with vac pump in the setup, that said both my 98s called for a 101" belt, the 100" just goes short too fast, and I had to go with a 99.5" for mine, I don't know if it's a belt geometry/pulley difference year to year or the rubber used in belts now isn't what it used to be. 1st time I did mine I bought the 3 closest sizes and took back the 2 that did not work.

 

[Dan Hunter]

Surveys are worthless without science. Even TD says "generally" regarding belt sizing and variances. The only way to actually sample experiences against results is with a pound measurement at the tensioner. I believe that tight belts contribute to fatigue on shafts and would prefer to run a belt just short of chirp. If the belt dies it's cheap compared to any part it drives. I do believe losing the drive resistance of the pump improves performance and it doesn't take much to cover the cost of the belt. Carry a spare and everything else is noise. Still like seeing "knkreb". Reminds me of when I found this group of people and my truck was "stock".

 

[matuva]

so the 99.5" belt is what you install for all vac pump delete situations, or is it just installed on 96+ trucks that have the pump deleted?

I have to check, but IIRC, for 1994-1995, the belt is a bit longer, and you should need a 100" after vac pump delete.
And yes, 99.5" is what you need for 1996 and above

 

[Turbine Doc]

GENERICally is what I said Dan , I've been running a 99.5" on mine for 5 years in the truck and about 3 or so on the burb if it was gonna lose a shaft or accessory it would have failed by now, what happened to mine 100" or matching the std rule of thumb to be 1" shorter the tensioner would be at optimum running range of the marks on tensioner.

Depending on the brand of the belt within 1 revolution of the engine or a couple of days the tensioner would go to max travel in the loose direction saying the just installed belt was bad and would squeak/squeal, changing to the 99.5" it fits just barely in the max direction and over tight indication, let it run depending on the belt it goes to the middle optimum mark and after time to the max slack depending on the mfr of the belt but it never squeals/squeaks until the belt back gets glazed over.