Hello folks. I posted this message in the Tech Help section earlier this week but did not get a response. Therefore, I am reposting it in the Diesel section in a final attempt to avoid having to buy a new pump:

Is the bi-pump located in the trunk of an '82 300SD re-buildable? I know that the pump is receiving voltage from the switch in the driver's door. Also, when the connector to the pump is removed and reinstalled (with driver's door locked), the pump will lock any doors that are open and run on for about 12-15 seconds. If I pinch the tubing at the outlet of the pump while the pump is running (with drivers door unlocked), I hear an audible popping sound and the pump will unlock the doors and stop within 3-5 seconds. Afterwards, I can lock the doors using the key but not unlock. I know that none of the elements are leaking, so I think the fault is with the pump. Any other suggestions, tips, tricks, or things to check before I buy a new pump?

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2001 Dodge Ram 2500 Cummins Turbo Diesel - 4x4, auto, 3.54 gears, long bed
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'92 300D 2.5 Turbodiesel - sold
'83 300D Turbodiesel - 4 speed manual/2.88 diff - sold
'87 300D Turbodiesel - sold
'82 300D Turbodiesel - sold

If the vacuum/pressure elements are in good condition then the pump should only run for 1-3 seconds, if it runs longer & you pinch off the line & it quits you HAVE a leak in the system!!

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Have you disconected the pump from the rest of the system and measured vacuum and running time directly at the pump?

Bob D.

M.B. Doc and Bob,

I thank you both for your responses. I did check the pump with the rest of the system isolated and the gauge on my hand pump showed that it pulled vacuum while it was running. I was testing the elements by getting the pump to run and manually tried to lock/unlock each door to see it the elements were leaking. All of them were difficult to lock/unlock while the pump was on, so I ASSumed that they were all OK. However, after reading Doc's post last night, I checked the system with the mighty vac and found that the passenger front element had a slow leak. I disconnected that particular line from the system and now the pump, trunk, fuel flap, and the remaining doors are working properly. Afterwards, I checked the system at the pump and noticed was still leaking but at an even slower rate than before. The system pump takes about 3-5 seconds to lock but less than 2 seconds to unlock. I'll be checking the other elements individually with the mighty vac tonight. Thanks again for your help.

__________________
2001 Dodge Ram 2500 Cummins Turbo Diesel - 4x4, auto, 3.54 gears, long bed
-------------------------------------
'92 300D 2.5 Turbodiesel - sold
'83 300D Turbodiesel - 4 speed manual/2.88 diff - sold
'87 300D Turbodiesel - sold
'82 300D Turbodiesel - sold