DIY turbo master-remove the old pump or leave it on?

[milliganman]

Will be fabricating the DIY TM and wondering if one could leave the old vac. pump on thereby not having to replace the serp. belt????? Also, what amount of lbs. turbo boost would be recommended??? I do have a gauge inside cab. thanx in advance...milliganman. '94 Sierra 4x4 with 6.5, 127,000 miles...a real gem!
Also just about to install a new inj. pump.

 

[Mezmorized]

5-7 lbs. is factory setting.

 

[ak diesel driver]

problem with leaving it on is that the pumps are known to sieze

 

[Turbine Doc]

X2 on seized vac pumps, I remove mine and IIRC also what Heath (OEM for the TM) recommends on his blog.

Depending on year (different pulley size & AC compressor location) the size of the non vac pump belt may vary.

The general rule of thumb is 1" shorter belt than your original when removing the vac pump, with the crappy rubber compounds in imported belts so far it has not mattered which belt maker I use; I actually wound up with a 1.5" shorter belt for mine.

The 1.5" shorter belt goes on very tight at 1st, requires much effort to move the tensioner to full travel, but by end of the week that belt is in the "normal" range on the tensioner wear/stretch marks, if I go with a 1" only shorter belt by weeks end the tensioners marks are in the too loose direction and in some belts actually slip/squeal