Engine/Transmission (1994 - 1998) what is a overflow valve?and

[vaicase]

what is it and what does it do?anything i can do to to it. adjust it or anything?if i need one can i just buy one from cummins napa or dodge?and is there a beter one than stock?thanks

 

[Joe G.]

Look at the side of the injection pump toward the engine and inline with the forward injection line. You will see what looks like a banjo fitting for the return steel fuel line. It's not normally adjustable. You an stretch the spring in it a little bit to give you more fuel pressure. Mine quit a few months ago. I bought a new one from TST Products. It provides more fuel pressure that the stock overflow valve, at least mine does. I now idle at about 30 PSI and my 40 PSI gauge is pegged a lot on the road.

 

[Bart]

I just ordered a new one from Piers diesel. In the mean time, I removed the oem one and cleaned it out. As was already said, on the front of the injection pump, close to the engine is the fuel return line. That line is held to the pump by a banjo bolt with a smaller bolt on top of it. Remove the larger bolt, and go to the vise on your work bench. Without too much pressure clamp the larger bolt in the wise and unscrew the smaller one. There is a spring several small shims and a check ball. Mine had some junk in it so I cleaned it with carb/brake spray. Before putting it back together I used some extremely fine wet/dry sand paper to smooth out the cooper sealing washer on top of the large bolt. Be careful to get those small washers (shims) all back in. I put the shims on the small bolt, followed by the spring and then set the check ball on top. The I lowered the larger bolt down on to the smaller bolt. Basicly upside down so that nothing got lost. Put it back on the pump. I don't know if it helped, but it didn't hurt and I'll always have a spare.

 

[vaicase]

wait just a second. there is something i dont understand. i took off the valve well i could not get it off without taking the thing apart. not room. well there were no shims. i stretched the spring put it back together. now it will rev in any gear way past 3500 no cutting in and out just go. now i need to do the valve springs. thanks

 

[Bart]

wait just a second. there is something i dont understand. i took off the valve well i could not get it off without taking the thing apart. not room. well there were no shims. i stretched the spring put it back together. now it will rev in any gear way past 3500 no cutting in and out just go. now i need to do the valve springs. thanks

Good Luck!!

There is a knock machined into the head/block or whatever just above the o. f. valve. I unscrewed mine and tipped it at an angle and it came right out. Then I could take it to the work bench and control the disassembly. If you took the top screw off while the banjo bolt was still bolted to the pump chances are good that you never saw those tiny little shims as the fell down into the engine under the pump. I dropped one of the rubber/steel sealing washers and it took me several minutes to find it and it was 10 times the size of those tiny 1/4" diameter shims. I have a shop manual and it states right in it "Not to remove the top bolt"

If you're now reving over 3500 rpms I do hope that you have already installed the 4K gsk. Otherwise, that 1/4" between the pistons and the valves might go to 0"

As I was not there to see what happened, I can only go by what I did just this last weekend. I much prefer working on that valve on the work bench as apposed to over the fender. Again Good Luck.

add on I just thought of something. Sometime back the metal tube for the overflow back to the tank cracked. Instead of replacing the steel line, I replaced it with fuel line hose. When I took off the o. f. v. the rubber line would let me move it around a lot more. Maybe this is the difference in our two rigs.

 

[hsmith]

Just a little work with a die grinder to the head above the overflow valve will give you enough room to remove it as an assembly.