If you are standing in front of the truck and looking towards the drivers seat there is something to the left of the brake fluid container that has a yellow off and on lever. what the heck is this and should it be turned off?
99 2500 ctd auto.

 

I believe what you are looking at is the drain valve for the fuel filter. Is there a clear section of tubing attached to the valve?

 

Sounds like the Fuel Filter Drain valve. Drain it every so often (some guys ever fuel fill up, others every week, whatever) to let water that has settled in the bottom of the canister to flow out. Im assuming this is what you are talking about as gad241 stated

 

There is a clear hose attached to it. Obviously this is my first diesel. So on drains it? I'll give it a try tonight. so much to learn.
Thanks

 

Don't get too happy when draining it, the engine will loose its prime and not start. Also, if your lift pump is bad, and they have been known to be bad and the truck still runs, after draining it will not start. Been there, done that, fortunately I was under warranty.
Side note: If you don't have a fuel pressure gauge, get one, if you do nothing else to the truck. The 60-100 bucks for the FP gauge and mounting may save you 1000+ bucks from the injector pump going bad because it has no fuel pressure. Fuel ONLY, lubricates and cools the injector pump on your engine.

BTW- I never drained mine, as I got fuel at reputable places that move a lot of fuel. Now I have had my FASS on for 3 years and have never touched the water separator on it.

Chris

 

I want to get a FP gauge, but I have no idea what to get or how to install it. I am trying to decide between a manual or electric gauge. When i picked it up and had some work done on it the dealer said the pump was "fine" whatever that means

 

Get a manual guage right away. They are easy to install. Don't use an isolator.

Without a FP guage you have no idea what the lift pump is doing. When the LP goes bad you'll want to replace it with an aftermarket pump.

 

I tend to think a mechanical gauge, with an isolator, is best, since sometimes an electrical gauge sending unit is unreliable on these engines due to excessive vibration. I like the isolator because I don't want to run diesel fuel into the cabin. I have heard if you spring a leak inside you'll never be able to get the odor out of the cabin. I like the smell of diesel, but not ALL the time.

Once you get your FP gauge you can tap into the fuel filter housing to get the readin. Remove the inner plug on top, closest to the center, which will give you the after-filter pressure, and put your gauge line in.

Chris