Hey I have a stupid question for you guys but I just want to make sure I'm right before I shell out the money for a new one. When the truck is running shouldn't the vac pump pulley be spinning??? Well mines not so I guess that means its out, now the next question. Has anyone replaced one theirselves, What are the steps.

 

Reference Material: Vacuum system
Why Does the 6.5 have a Vacuum Pump?
Diesels do not create vacuum inside of the intake like gasoline engines. Gasoline engines rely on vacuum for numerous things, such as: brake boost and HVAC controls. The Diesels rely on hydroboost systems for brake boost and electrical motors for HVAC operations. GM put the vacuum pump to control a couple of devices on the truck, read on for more info.

So, where's the vacuum pump?
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Please note, you may not have the piece of tubing in the way unless you have an intercooler.

What components does the vacuum pump provide for? The list includes: EGR (if equipped) and the turbo waste gate system.

On vans the vacuum system also controls the HVAC system.
EGR's are normally found on "S" Vin engines. Another way to tell is if the truck is a 6 or 5 lug, it will have an EGR (unless its been removed).

Where are these EGR and Wastegate solenoids?

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So how do I know if my vacuum pump is working correctly?
You will need a vacuum gauge to properly test the pump itself. You will want to hook the gauge up as close to the pump as possible. You want to see at least 20”+ Hg of vacuum at Idle.

Do I have to hook directly up to the vacuum pump?
It is best if you do, however, you can test farther out on the on the vacuum system. You can check the vacuum at the soleniods, EGR, wastegate. This will help you determine if it is a bad device or a bad vacuum line if the vacuum pump tests good.
*Note: Testing after the solenoids may give a skewed reading as they regulate the amount of vacuum given to the devices.

My vacuum level is not very good?
If you are directly attached the gauge to the pump, and you have low or no vacuum, then your pump is bad. If testing further out on the system, you will need to connect directly to the pump to insure that you have no leaks in the lines between the gauge and the pump.

Are leaks common?
Very common. Leaks come from chaffing, hardened plastic lines cracking, etc... Sometimes the vacuum level may be okay, but if the engine rocks one side to another, it may open up a crack in the line and you will lose vacuum.

I don’t have a gauge, but I suspect I don’t have good vacuum. What do I do?
A real quick check of your vacuum system, which can be done at any time, is checking your waste gate actuator.

With the engine at idle, locate the turbo, and the can on the side that has the arm in it, should be drawn up inside. Pull on it, to see if you can pull it out. If you can, you don’t have sufficient vacuum. That is not to say that the pump is bad, but just an indicator that you vacuum level to the turbo portion is not enough. You will need to do further troubleshooting to determine what’s wrong. If it doesn't move then you most likely have enough vacuum at the wastegate.

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My waste gate actuator failed the test, now what?
You will need to determine if the waste gate solenoid is bad, have a leak, or bad vacuum pump.

How do I determine if my waste gate solenoid is bad?
Check to see if you have vacuum BEFORE the solenoid. These solenoids will go bad after some time. The little ball inside of them will rust that actually opens and closes the vacuum to the actuator. It will get stuck not properly regulate the vacuum. It may get stuck “off” which means no vacuum gets to the actuator, it may get stuck “on” where it has full vacuum all the time. The last condition would create a DTC (computer code for over-boost).

How do I check to see if I have computer codes?
Depends upon if you have an OBD-I or OBD-II computer. 1996 and after are OBD-II and require a code reader, pre 96 you can check with a paperclip. Check the FAQ’s.

I have a code for my turbo, and EGR.
Coupled together these two codes indicate a vacuum problem. Both systems rely upon the vacuum system to work properly.

I have a heavy duty vehicle that does not have an EGR. My vacuum system is not working, what are my options?
If you have a 2500HD or 3500 truck, not equipped with an EGR system, you may opt to abandon your vacuum system, and use strictly a spring tension waste gate operator. Instead of using a vacuum system to hold the waste gate closed, you use spring tension. Once boost is built to it’s maximum allowable level, the waste gate blows open. The spring tension provides the proper pressure to maintain a safe boost level.

Can I get more boost out of my turbo with a spring type waste gate actuator?
Yes, but remember, there is a limitation here for the engine. You don’t want to be driving more than 12 psi of boost pressure into the engine with stock tuning, or more then 15 psi with an aftermarket tune.

Where can I get one of these spring type waste gate operators?
There are over the counter ones available from vendors, or you can opt to build you own (Check the FAQ’s). Other members have done so, and you can search to see what they have built. Search the term "Turbo Master."

*NOTE: If you install a Turbo Master, your computer will no longer be able to control boost levels.
I have an EGR system, can I fully abandon my vacuum system?
No, you will still need vacuum for your EGR to work properly.

You must still leave all your solenoids hooked up to the electrical system, because the computer is looking for feedback and a circuit to them. Without them connected, the computer will generate a DTC code. You can only remove the solenoids and EGR if you have an F code computer or an aftermarket tune that has EGR Delete on it.

What would keep me from abandoning the vacuum system?
If you have an EGR or your HVAC controls are vacuum operated.

If I abandon the vacuum system, can I remove my vacuum pump?
Yes, you can, this means that you will require a shorter serpentine belt. Members have reported that it needs to be 1 inch shorter than your original, you may want to do some further investigating to make sure on your own.

Normal Vacuum Pump Delete sizes are:

* 94-95 :: 101.5"
* 96+ :: 99.5"

this may be some help

 

Couple more questions if you don't mind, what is the egr? My truck is a turbo so if i build the spring type can I get away from the vacuum pump all together?????? Also do you have the link to building one so I can see what springs are used and then I can make the rest of the parts.

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I also read on an old entry that you can turn and screw to get more or less boost, is that correct?

 

EGR is on top of your intake right in the middle of if you want to get rid of the vac pump you have to ether put on F intake or gut your S intake


yes you can turn your boost but if don't have boost and EGT gauges i wouldn't turn up boost with out them and do have them you can turn up to about 10psi before puter will set the SEL off or defuel you


Here's the adj controller i fabbed up. Hope it helps ya'll.
First pic is the original with the "lip" ground off and pop'd apart with the new 1/4" rod i bent. Second is the thing attached, third is the adj end. Total cost $5.97. I measured the length between the inside of the lever hole to the step on the original rod. Then when i installed it, made the length the same. 10 5/8" on the GM-3. After i get the truck back together, i'll use the pyro & boost gauges to set the boost and turn up the 4911 if needed.

 

egr takes spent exhaust gasses and reintroduces them into the engine. its a emissions thing really. i would suggest cleaning your intake pericodically if you do have egr. it accumlates black dirty sluge that can get into your engine. also your going to need a boost gauge if you run a turbomaster cause you need to find how much your making

 

Whats the best way to clean the intake and where would I need to hook up the boost gauge at on the engine?

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What does the egr look like so I know I'm looking at the right thing. Sorry for sounding stupid but this diesel stuff is all new to me

 

Here some info and pics set up boost gauge

autometer boost gauge install with pics
after not finding a good write up i made my own .... here you go

parts needed

---autometer boost gauge ( or other as long as it has the 1/8npt fitting)

---1/8-27 npt pipe thread tap

---5/16 drill bit

---male 1/8npt compression fitting ( i just got the nylon hose kit from sunpro, available at autozone or advance)

you could probably find the fitting without getting the kit but i just got it because it was convenient at the time

this write up may be elementary to some, but im sure some will appreciate it ...

i appologize for the low quality cellphone pics... forgive me (hehe)

First, take off your upper intake manifold, theres 6 bolts on top, 2 sensors to unplug, and the hose and brace to the turbo.

Then decide where your going to have your boost source location, i chose the back right side, put your intake in a vise so its stable to drill, (if you dont have a vise you should go buy one immediately)


be sure you have the intake in the vise so the surface your working with is flat, then drill the 5/16 hole where desired. put the tap in the hole with the tapping tool, make sure its level and with good pressure start turning the tap clockwise in the hole, this is the most crucial part to get right. the tap will begin to cut into the hole, making the threads. once you see the tap get through to the bottom a lil bit youll want to back the tap out and back in a few times to clear the new threads of metal shavings



right here is about where you want to stop so you can make good use of the threads. since pipe threads are tapered you can make the hole a lil too big and the fitting wont fit as snug as youd like.


back out the tap and make sure all metal shavings are cleaned up


now get your male 1/8npt fitting and wrap some teflon tape around it. this will give it a good seal. screw in the fitting and DONT over tighten, cast aluminum is not the strongest metal!

 

EGR is right in the middle of top upper intake on the first pic and second pic diff between F and S intake

 

Fr cleaning intake i used brake cleaning and make sure let dry good and when put it back to getter make sure seal the boot between turbo and upper intake with good rtv sealant

 

So if I put my intake on a mill and mill out the internal parts of it and make it look like the F intake then I can get rid of my egr and vacuum pump and put on a turbo master and guage. What springs where used?