[96GMC6.5L]

What kind of, and size of tees do you need to tap into the orange and black vac lines. What kind of caps go onto these tees? Any pics of this? Can you use the tee you get with your boost guage and that rubber thing I don't know what it is called? Should be getting my gauge tomorrow, so I am trying to gather some info on how to do this.

Thanks, Jacob

 

[jackb]

What do you want a vacuum gauge for? The vacuum pump puts out the same amount of vacuum regardless of boost, all it does is actuate the WG rod open or closed depending on the signal the WG solenoid puts out.

 

[Dave12]

Jacob,

I'm planning on using the "T" that came with my Auto Meter boost gauge to do an install of my old boost/vac gauge as a vac gauge.

I think all you will need is another one of the little rubber "boots" that attach the line to the solenoid. What I plan to do is remove the line from the solenoid, remove the boot and put one end of the "T" in it and then attach that back to the solenoid. Get a second boot and put it on the other side of the T, insert the line back in there. The kit came with a boot to attach to the bottom of the T for the line to the gauge.

Maybe there is another way to do it that would be better.

Dave

 

[Dave12]

What do you want a vacuum gauge for? The vacuum pump puts out the same amount of vacuum regardless of boost, all it does is actuate the WG rod open or closed depending on the signal the WG solenoid puts out.

Come on jackb....gauges are cool! I don't know if I'd go out and buy a vacuum gauge but my old boost gauge is also a vac gauge so I might as well use it. Seems to be it's just going to be a constant monitoring device for the vac system.

Dave

 

[DavidPhillips]

If your continuously monitoring it I would put it on the vacuum pump line where it goes into the solenoid.

That way your checking the line and the pump.

The PCM monitors the EGR if you have one, and you will know if you have a boost problem. Make your hoses so you could swap them over to the other side of the solenoid to troubleshoot a problem.

 

[96GMC6.5L]

I was planning on doing something similar to what Dave said too. Except I was going to put a tee in both vac lines, the one from the pump to the selonoid (I think is orange line), and one in the line from the actuator to the selenoid. That way I can see if both are holding the right amount of vaccum. Shouldn't it be like 25inches and 15 inches for each line?

Thanks, Jacob

 

[DavidPhillips]

yep, 25 to 26" from the pump at idle.

If the pumps good at the solenoid and you get an error 78 or equivalent OBD2 code you know where to start looking.

 

[96GMC6.5L]

Is it supposed to be around 15 at the wastegate arm? Is this a good way to do it, with a tee in both lines so that both can be checked when needed? Only problem is that I can't check codes, I have no reader.

Thanks, Jacob

 

[DavidPhillips]

Would work. I would just have a short hose on one end, gauge on the T and plug the vacuum line on the other end. Could be swapped easy enough.

If you ever get a SES light you'll need to get it checked before you know what to do.

 

[cool_fool]

Is it supposed to be around 15 at the wastegate arm? Is this a good way to do it, with a tee in both lines so that both can be checked when needed? Only problem is that I can't check codes, I have no reader.

Thanks, Jacob

Harborfreight has a cheepie scanner. I have seen them in the circular for $19. Might hit a few pawn shops for a cheap one as well. It's a great tool to have in your toolbox.

 

[96GMC6.5L]

Would work. I would just have a short hose on one end, gauge on the T and plug the vacuum line on the other end. Could be swapped easy enough.

If you ever get a SES light you'll need to get it checked before you know what to do.

I think I see what you are saying, you would unplug each hose directly from its source, and put the T on the end of the vac hose, and then put another hose on the other end of the T, and get a reading with the gauge. That way there involves no cutting of lines, and when your done you just take the T off and plug the vac hose back in. Am I right? Which method do you think is better?

 

[DavidPhillips]

Yep, that's what I was saying.

If I were going to monitor something like that I would monitor the vacuum at the solenoid coming from the pump.

 

[Turbine Doc]

What do you want a vacuum gauge for? The vacuum pump puts out the same amount of vacuum regardless of boost, all it does is actuate the WG rod open or closed depending on the signal the WG solenoid puts out.

My recommendation to him in PM was to get one for diagnostic purposes, not a permanent install, diagnostic vac/press gauge can be used at various places especially on a S truck with more than one solenoid that needs to be looked at for vac(even though his is a F truck), plus in pressure mode can be used for diagnosing lift pump issues. For a even a F truck it would be handy to know if you are getting vaccum loss under load from the WG solenoid, IIRC some fail after getting hot, but work fine at idle.

IMO for about $20 it is a handy piece of test equipment, every 6.5er should have one, back in the day with gassers you did not do tune up without one either, still plays a part with those as well

 

[DavidPhillips]

Yep, not much good for full time gauge but a must have for testing.

 

[96GMC6.5L]

I did get a 25 dollar test gauge. Except what I was going to do is tap into the lines somewhere in the middle with a T and cap it when not in use. The tees would become permanent unless the line was changed, and when you wanted to check it all you have to do is take the cap off and plug in the test gauge. Is this a good way or what? By looks of things you guys are against doing things this way.

Thanks, Jacob

 

[Mverick]

I have a full time gauge with a warning light. But, it's for vacume actuated trailer brakes.

 

[DavidPhillips]

Nothing against it, just it's not really a common thing to check until there is a problem.

What your saying won't hurt anything.

 

[96GMC6.5L]

O.K. Thanks, Jacob

I might be doing this tomorrow not sure, and gutting the cat monday.