I'm Installing a new overflow valve in my truck today or tommorow. Is there anything i need to be aware of while installing it? I have never done one of these but i'm pretty confident with a wrench. Any wisdom would be appreciated.

 

Hello, stuff a rag between the pump and the block to prevent any loss of a washer or shim, they are small and easily dropped into never never land. If you can, get a new set of rubber washers as well. You can usually get away with re-using the old ones a few times, but then again theres Murphy's law. Also use some oil, fuel or wd-40 on the rubber washers for reassembly. I like to spray them with the wd-40 before I try to remove the overflow valve. Keep everything clean, and thats about it. Pretty easy to do. Throw the old one in the glove box just for a spare (if truck still runs with the old one). Good luck, Kevin

 

Thanks alot. I will be attempting this in the morning. I'm hopeing to get some power and some MPG out of it.

 

Easy 5 minute job if you don't lose the washers.
On some engines there's not enough room for the valve to come out do not bend the line to get it out, it will be hard to get it lined up right again.
Instead grind or file the part of the intake manifold where it hits.

 

Well Ok, I feel stupid! It took me all of about 5 minutes to do. I worry about too much. If only the rear shocks were just as easy to replace

 

Did it help?
Scott

 

I can tell I little bit better throttle repsonse. That annoying ticking is gone!
I guess the real test will be the next tank of fuel, see if I got any more MPG.
It may Be just me but i think the injection pump is more quiet. The old valve looked good, but i have no idea what i'm looking at. I just threw it in the tool box as a back up just as kd460 suggested. Thanks for the help guys!!!

-Kyle

 

Sooo, what are the results? Any better MPG?

 

Oh yea! I put 3000 miles on my truck this week. Best MPG was 26.5 (I was going 55 MPH on the interstate unloaded) But i'm getting about 18 MPG running 75-80 MPH unloaded on the interstate, up from 13 MPG. $30 and 5 minutes, well worth it!!!

 

Where can overflow valves be purchased other than Cummins? This may be my problem as I was only getting 13 mpg on my stock truck no matter what.

 

You won't find a better price

Precision Diesel Injection and Turbo Inc.
Marty Tompkins
888-734-7349
$22 + $5 shipping and handling.

 

Is there any way to tell when the overflow valve needs to be replaced other than the fuel pressure reading? Mine is currently running fine, although winter fuel and city driving seem to be killing off the fuel mileage. Should I replace this valve at a given mileage or age of the truck? Mine's got 110k on it.

 

I tried to change my fuel filter, drive less agressive, keep my speed down but no luck. So after reading the other posts on the overflow valve I made a decision to
change it. I took infidel's advice and called Precision diesel injection and they hooked me up. I think the price went up, but it was still under $40 with shipping. That's the best price i could find also. There is a procedure on how to check the valve but I'm no good at computer stuff, so i cannot give you the link. Maybe someone will chime in with the link. My truck had 144k on it when I changed mine. It made a big difference. Good Luck

-Kyle

 

Cool. The thing that scared me off was I remember seeing prices of $200! But for 40 bucks, I'll order it tomarrow!!! Thanks for the update.

 

When you take the valve out, the spring should be 450 to 500 thou.

My spring came out in three or four pieces.