Vacuum hose, oil pressure problem

[hauling4you]

I have found what I believe is the problem with having no vacuum to run the defroster & cruise control. So I repaired the line only to find another, repaired that one and decided to run a test to see if i got it right, started the truck and no oil pressure. The truck runs 15W-40 Rotella T, and it was around 40 deg. outside. O ya it was a cold start also, had no been run for about 2 days. The last trip out I when mudding and was in about 2.5' of water/mud, and light snow. Also of water did splash in the engine bay, could I have killed the stock gauge or the connectors, how reliable are the guages really? Should I just get an after market and hook it up and see then? Any answers would be helpful. I'm completely new to GMC/Chevy diesels, I've always been a ford diesel guy. The second part is sence no one out there seams to have a vacuum diagram for this truck, then how many feet of 1/4" vacuum tube should I buy to replace all the underhood conections, also what other sizes and how much of it should I get? this way I do not havt to take it all off and make my own diagram, I will if need be just wondering if anyone elce has yet.

Dave

 

[imiceman44]

I have found what I believe is the problem with having no vacuum to run the defroster & cruise control. So I repaired the line only to find another, repaired that one and decided to run a test to see if i got it right, started the truck and no oil pressure. The truck runs 15W-40 Rotella T, and it was around 40 deg. outside. O ya it was a cold start also, had no been run for about 2 days. The last trip out I when mudding and was in about 2.5' of water/mud, and light snow. Also of water did splash in the engine bay, could I have killed the stock gauge or the connectors, how reliable are the guages really? Should I just get an after market and hook it up and see then? Any answers would be helpful. I'm completely new to GMC/Chevy diesels, I've always been a ford diesel guy. The second part is sence no one out there seams to have a vacuum diagram for this truck, then how many feet of 1/4" vacuum tube should I buy to replace all the underhood conections, also what other sizes and how much of it should I get? this way I do not havt to take it all off and make my own diagram, I will if need be just wondering if anyone elce has yet.

Dave

I don't know how much hose you need but I would buy 10 feet or 15, but I have more than one truck so it wouldn't go to waste
As for the oil pressure guage, I would say no they are not reliable, either change the guages or get a temp guage.
If it shows no pressure there is definitely something wrong with the guage you will have some kind of pressure especially when it's cold it will have more pressure than when the oil thins out when hot.

 

[BKinzey]

I would recommend assuming your gauge is correct until you can confirm it isn't.

I thought what's wrong with the oil gauge? Then another mile or two down the road a thump - thump - thump told me nothing is wrong with the oil gauge

Toasted my first 6.2

 

[imiceman44]

I would recommend assuming your gauge is correct until you can confirm it isn't.

I thought what's wrong with the oil gauge? Then another mile or two down the road a thump - thump - thump told me nothing is wrong with the oil gauge

Toasted my first 6.2

I agree, but I am talking from experience too, if it doesn't move I assume it's bad and change it or check it, not drive thinking there is nothing wrong with the engine and it's a bad guage.
I have had sooo many bad guages and last time I assumed it was good and tore down and engine on the road because it acted like there was no oil pressure, turns out I flatened the cam