Engine/Transmission (1994 - 1998) Does a 98 have a vaccuum pump?

[pwerwagn]

Do truck with hydroboost brakes still have vaccuum pumps? If so, whats the purpose?

--Jeff

 

[mschoenheider]

Mine does. Vacuum is used to actuate the cruise control servo, HVAC routing and front axle disconnect for 4x4s. Probably other uses too.

 

[pwerwagn]

I hadnt thought about the HVAC and CAD.

Does anyone know approx how much vaccuum (in Hg) the pump produces?

 

[T-Bone]

I think it is 20 to 25Hg.



T-Bone

 

[TPCDrafting]

It runs the Pacbrake too! Oo.

 

[pwerwagn]

Your right on T-bone. I put a gauge on it last night, and at idle it is consistently around 20-22 in/hg. If you rev it slightly, it climbs to about 24in/hg.

--Jeff