Engine/Transmission (1994 - 1998) Fuel Leak after Timing Adjust

[mikel]

Hey gang,



A couple of weeks ago I got the timing on my truck adjusted up to ~15. 5. The truck has been running fine since then, but this weekend I noticed that the #1 delivery valve "holder" was all wet with fuel. This is the one that was removed to set the timing. It looks to be wet at the bottom so I suspect the leak is at the bottom, not the top because right at the top where the metal line screws on it is still dry.



So here's the question; I know there is an o-ring in there and I suspect that is what is leaking. How hard is this o-ring going to be to locate, and is there anything else in this area that might have been disturbed when the timing was set to cause a fuel leak?



Last question, is there any chance of hurting something to drive it with a leak until I can get the o-ring and goofy socket that I need to take it back apart again?



Thanks,

Mike

 

[illflem]

On your '95 pump it is recommended that the sealing washer inside the delivery valve be replaced after setting the timing, my bet it probably wasn't. The o-ring is designed to keep dirt out, not fuel in, don't think it could take the high fuel pressure.

 

[Howard Durand]

I have had mine out a couple of times. The "O" ring is there to prevent dirt and water from getting down along side the delivery valve holder and into the pump. I doubt if it is the problem.

The seal is at the bottom of the delivery valve where it mates up with the pump. On most pumps, there is a copper washer that can be replaced. That is probably where the leak is.



Once you get the socket, make sure the valve holder was tightened properly. It should have been torqued to 85 ft. pounds.

If it is tight, and still leaks, then you will have to replace the washer.



If the delivery valve holder is just "wet" with fuel after driving, I doubt if the leak will cause any problem until you can get one of the sockets.

If fuel is running down the side of the pump, I would wait.



TSB 18-10-94 Rev. A gives a good description on how to set the timing along with removal and replacement of the delivery valve.

 

[mikel]

Thanks for the reply. I know for a fact that all the pieces were re-used, I watched the procedure.



If I wanted to get a new sealing washer and o-ring, is this something I can get from cummins? Can they just look it up based on engine serial number or am I going to have a bunch of trouble finding these parts?



Thanks,

Mike

 

[Howard Durand]

I didn't replace either the "O" ring or washer when I changed my timing so don't know about getting parts.

Check with Cummins first but you may have to go to Bosch.

According to the TSB, the part number for the washer is 4778483.

Unless the "O" ring is damaged, I would re-use it.

 

[mikel]

Thanks again. I'll get the stuff to take care of this and get it knocked out.



The DV holder is just wet, it isn't dripping so I hope it's not a big deal to run it this way.



Mike