Vacuum pump question

[Ole BlackBetty]

What does the vacuum pump supply vacuum too, other than the brake booster ?

 

[IDIoit]

runs all of your heater/ac controls
and cruise control

 

[franklin2]

Also for shifting of the c6 automatic if you had a older truck.

 

[Ole BlackBetty]

So it has nothing to do with the injector pump or e4od trans?

 

[Ole BlackBetty]

I'm pretty sure mine went out friday, hard brake pedal and when I pull the hose from brake booster and put my thumb over it at idle, it barely has any vacuum.

 

[cpdenton]

On your truck, the only thing it controls are the brake booster and the ac vent blend doors.

You should have electronic cruise control on your year model.

Hydroboost brakes and a small electric power stroke vacuum pump can get rid of it altogether.

 

[OLDBULL8]

Twenty one year old vacuum lines can get hard and crack. Take the vacuum line off the pump and check there. Good vacuum, then lines need to be replaced. Large line going to the booster rarely cracks. Any auto parts store has replacement lines in bulk. At idle, you should have 18 to 20 (Hg) inches of vacuum.

You might have vacuum actuated front wheel locking also.

 

[IDIoit]

the IP has no vacuum to it at all...

 

[Ole BlackBetty]

Thanks you for all your answers. I'll have to check into it more before I drop 139.00 bucks for a new pump! On a side note who has a used one for sale and how much ?

 

[OLDBULL8]

Look in the Marketplace forum, then search "vacuum pump" in there.

If you buy a new pump, be sure and specify it's for a Serpentine belt engine, if that's what you have, the pulley shafts are different from a V-belt drive, they do not come with a pulley, you have to use the one on yours.

 

[icanfixall]

The V belt vacuum pump has threaded mounting holes in the pump body where the serpentine belt pump has just drilled holes with no threads. You can drill out the threads on the V belt pumps and use them on the serpentine belt applications.

 

[Ole BlackBetty]

Ok it has some vacuum, haven't checked it with a gauge yet. I have a real hard pedal on brake, put on a new booster a out 4 months ago . Complete new back brakes hubs and all. Did not change master cylinder. What else could cause a hard pedal

 

[franklin2]

Low vacuum causes a hard pedal. Try it on a gas vehicle. With the engine off you have a hard pedal.

 

[opusd2]

Seriously consider going with an electric pump off of a SD truck if you don't like messing with belts or tension. Besides they are easy to hook up and will continue to give you brakes even if the engine kills on a hill.

All I have my pump for is my AC controls and Cruise. I went Hydroboost and wouldn't have any other kind of brakes.

 

[opusd2]

As an addendum, if you are looking at $139 for a new mechanical vacuum pump, the electrical isn't that far away price wise. From what I've found, anyway...