Overflow Valve

[Archive]

My truck idles rough and I have had the injectors checked and valves have been adjusted... I have heard alot about the overflow valve being a problem with rough idle and general missing... Can anyone explain in detail how to fix the overflow valve problem, how to take it apart and what I am looking for, and how to fix it. . ???

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Jeff Pilnicki, '94 Dodge Ram 2500, Auto transmission, Mostly stock, Chrome Brush guard, modifying exhaust to straight 4" pipe w/5" tip

 

[Archive]

Jeff,

Any fix to the overflow valve is temporary. You can stretch the spring a little and help the situation but that weakens the string. It's not long before the problem returns. I made a little shim about 1/16" thick for mine to increase the sping pressure. That's still working after 10K miles or so, but I don't expect it to last. As far as I know there are no repair parts for this valve. The valve is easy to take off the pump. It's on the side of the pump toward the engine and in line with the forward delivery valve. It looks something like a banjo fitting. Before you take it out cram some rags between the pump and the engine to catch any dropped flat washers. It's easy to take apart.

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Joe George
Eureka, CA

'95 2500 CC auto 4X4,3. 54,Combo EGT/boost guage,custom switch panel,PacBrake,TST #5,BD valve body,Automatic motorhome steps on both sides,Foldacover hard bed cover,Cummins chrome kit,Black steel grill guard,Front hitch receiver

 

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Jeff
Try this before you spend a lot of money.
While your truck is at an idle, take a wrench and loosen the injector line to the injectors one at a time, when you open the line the injector will star missing, do this to all of the injectors one at a time.
If this makes a differnce in the idle rpm it is not a problem with your injectors.
Most truck with bad overflow valve are hard to start.
John

 

[Archive]

My overflow valve was bad but no misses or hard starting only power loss above 60mph with RV in tow and not as responsive to throttle at higher speeds when empty. Remove the valve and stretch the spring to. 550 and reinstall. A new one is supposed to be . 500. I did mine 8 months ago and it still is working fine. My local injection shop wants about $60. 00 for a new Bosch valve assembly and Cummins and Dodge are more.
Good Luck

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96 SLT Laramie CC 5spd, 3. 54, no muff, no cat, 5"turn down tip
. Member NRA/USPSA

 

[Archive]

Jeff,

Does your truck tend to miss & idle rough when its HOT? This is when the overflow valve usally acts up.

You may be confused if you look at your overflow valve. The OE one on my '94 was a sealed unit. It had a steel ball pressed into the top of it. No way was it coming out without destroying the valve. The newer ones the guys area taking about have a hex nut on the top of the valve. This can be unscrewed and the spring removed and streched.

If yours has a 'ball' like a ball bearing pressed into the top of the oveflow valve, get a new one. #ad


I wish I had a scanner to show you guys, I have the old OE valve in my hand.

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Bill R
94 2500 SLT 4x4 5 Speed, 3. 54 LS, JRE 4" exhaust, Autometer Pyro, Boost & Water temp gauges, Bosch 215 HP injectors, Timing @ 14. 7º, JRE Stage III #4 plate 270/675, AFC spring kit, Scotty Air, Bully Dog Propane Injection, Roadmaster Active Suspension, Optima Red Tops, Geno's Exhaust Blanket, Espar Heater (won it!), Synthetic lubes throughout.



[This message has been edited by HEMI®Dart (edited 01-15-2001). ]