Archived 94 2500

[DU516]

I recently took my truck to the dealer to have them check out some of the problems I've been having with my truck. After being their for 2 weeks they are telling me that my overflow valve is bad

from what they have told me I have 20 psi of fuel and should have 25 and by replacing the overflow valve it should solve my problem ? My only problem with the whole thing is I've already replaced the lift pump and still nothing has changed the truck stalls out and is hard to restart. From recent posts I order a PTO cable to replace the fuel solenoid but haven't got around to it yet.

What I'm try to get to is what is the overflow valve what does it do and how hard is it to replace. Any help would and will be greatly appreciated. Thanks.

 

[Joe G.]

It may be the overflow valve, but 20PSI should be ok. It's on the low side of normal, but should not cause your problem. It's easy to change. Look on the engine side of your injection pump even with the first delivery valve. The overflow valve is down on the side of the injection pump. It looks like a banjo fitting. Before removing it cram some rags in the space below it to catch the washer gaskets. There are two screw heads. Don't remove the small one until you have the valve out. Piers has the best price for a new valve. You might try stretching the spring in it a bit to see if that affects the problem. If that fixes it you might be ok to run it that way for a while. Mine has gone about 120K miles since I stretched it.



After saying all that, I think your problem is caused by leaking fuel hoses. There are two of them, supply and return. The leak might not be observable since the hoses get old and suck air. If they suck air it will be hard to start for sure. IF the hoses have not been replaced try that first.



I doubt that it's the solenoid valve. When that fails it usually won't start unless it's pushed up by hand.

 

[DU516]

Thanks

Joe, thanks for the advice I got a new overflow valve yesterday and put it in I drove the truck about 30 miles and it did it again but then after I restared it ran fine I drove it at least another 50 miles or so and no problems. I'm going to replace the fuel lines the next day I get off work witch will be Thursday. Thanks again you saved me about $330. 00 the dealer said it was a 3 hour job to replace the overflow valve took me about 10 minutes.

 

[Joe G.]

The hoses are two sizes. I think 3/8" and 5/16" but not sure. Maybe someone will chime in here who knows.



Changing the hoses can be a royal pain in the hieny. No room to work. If you need a fuel filter change, now is the time to do it. The fuel filter is in the way so if it's off you have more room. Remove the two nuts that fasten the master cylinder to the booster and lean it toward the fender. That helps a lot. If the hoses have never been changed then you will need new clamps. The original ones are the crimp on kind that you have to cut off. If you still need room, take the starter off. Don't cuss too much!

 

[DU516]

Ever since i took the truck to the dealer. The truck shifts into over drive at 45 it used to shift at about 50 or so any Ideas . When it shifts now it seems like it's in to high of a gear. Once I speed up it's fine but I cruiseing at 45 I have turn the overdive off.

 

[Joe G.]

I dunno. You have a 47RH so there is not much electronic stuff to do with shifting. Two things you might try. Adjust the kick down cable. With the throttle pedal on the floor there should be just a little movement left in the kick down lever on the transmission. Takes two guys or a stick against the power seat to hold the pedal down. IF the kick down cable needs adjustment there is an easy way to do it. Get a 2" C-clamp. Use it to press and hold the cable adjustment button. There are three cables in the linkage mess on the side of the injection pump. One is the throttle cable, another is the cruise control cable, and the other is the kick down cable. The kick down cable is the one on the bottom. It has a pointed end. The adjustment button is in the black looking cube that the cable housing comes out of. The adjustment is a little confusing. What is really adjusted is the length of the cable housing, not the cable. So to make the cable "longer" you make the housing shorter. The cube has a bump on one side. This is NOT the button. It is a spring housing for the button spring. The button is the flat place on the other side of the cube. Use the C-clamp on the flat place and the bump to press and hold the button. I hope that makes sense.



The other thing is to adjust the TPS. Your manual will describe how to do that adjustment. My manual is not handy to quote from. You have to be careful with that adjustment so that you still have full throttle and the idle stop will still stop the throttle lever. Sometimes it's impossible to get the voltage right and still have the linkage work right. Don't cuss too much.