Fuel leak under injection pump

[KrisML]

Ok so I'm slowly rebuilding the 6.5 that died in my stepside plus I'm doing a whole bunch of other work while the engine is out and money allows me too. I have the engine built to a complete short block with the injection pump installed. It's a DB2 pump with only 4000 miles on it. The engine has been apart for about 18 months, so obviously no fuel has been put through the pump for that whole time. Just whatever little was left form when it last ran. Pump sat covered in the corner of my garage and never leaked a drop. I install in on the engine about a week ago and today I notice a little puddle of fuel under the pump about the size of a silver dollar. Nobody has touched anything on the engine for it to be there and I can't tell where from the pump it would have come from. So I'm guessing maybe a seal is drying out from just sitting which I can see happening. My question is should I chance running and hope I get lucky or are there some easy seals to replace on the DB2. Also I never unbolted it from the timing cover so I wouldn't have to retime it. I have need to get a timing tool one day. I could send it out but I'd rather not as its a .033 plunger pump with a 4200 rpm governor( least that's what I was told it was) and I haven't had any other issues with it.

I'm sure I can fix whatever is wrong with it myself, just not fully sure where to look just yet.

Thanks in advance.

 

[Will L.]

Cap return port, use a bicycle pump hooked up to fuel supply and bring it up to 15psi. Dish soap & water in a spay bottle and spray the outside of the pump looking for bubbles.

 

[KrisML]

Hmm, didn't even think of that. I'll have to try that when I get home from work tomorrow. Thanks.

 

[KrisML]

Ok, I think I found where its coming from. According to the manual its the piston hole plug (trimmer side). Looks likes its coming right out from the center portion of it. Is there a seal behide that, that can be changed? Or is it more involved to fix?

 

[3500GMC]

Timing retard plunger. Under a lever deal?.. There is a small lip seal in the center of that 'plug'..

 

[WarWagon]

I would send the pump out to be resealed. Any air leaks that don't leak fuel with give you hours of hard starting. Timing is simply line to line or done by ear. Really, nothing hard about timing the DB2 by ear or smoke output.

 

[KrisML]

Yep it's the plug that's under the lever on the passenger side of the pump. It's actually a very faint drip. when I had it pressurized it didn't increase the rate of leakage any. Actually when I would release the air most would come back out through the fuel inlet that I was feeding it in to.

Sending it out to be resealed is certainly an option, I just have to find some where near me that will do that and not want to just exchange it for another one. Are parts like the seals easy to get? If I can do it myself I'd rather. I even have an old DB2 pump that's missing the top solenoid section that I can practice on first. Anything super special needed to take one apart? The service manual gives fairly good details of how too.

True, no reason I can't get it back to where it is timing wise. I should get the special wrenches to make it easier to adjust once it's back in the truck.

 

[KrisML]

So found an injection shop in the area. Guy said that those seals are only changable by pulling the whole pump apart. Which while you're in there you might as well do a full rebuild which cost between $500 and $600 depending on parts needed. So looks like I'm getting the pump rebuilt once I have the money to do so.

 

[3500GMC]

Don't think so. To do all seals yeah, but your offending seal, no.

 

[KrisML]

I don't think it all needs to come apart either, but having never taken one apart its hard to tell from pictures in the manual. I do have an extra DB2 for the 6.2 that I bought but its not a complete pump to try a "test" teardown on.

Seal kits that are on ebay are cheap enough, guess I can pick one up and try it. Worse thing that happens I take it to be rebuilt.

 

[Will L.]

Always worth a try to learn. Set up a video camera while you do tear down to help you with any confusion for when you go back together.

 

[merlinhenry]

Go to local diesel shop & get a rebuilt throttle lever cover & seals & gasket & remove 2 nuts that hold cover to pump & the shut off mechanism will fall out of place & then the spring from the throttle linkage to the pump will have to be taken off remembering the hole the spring goes on. This can be done on the engine as long as you are clean & careful not to drop things & remembering where things go. The throttle linkage wears into the aluminum housing over time & needs replaced.

 

[WarWagon]

It has a fuel leak from a bad timing retard lever. Do you plug the leak and hope other gaskets are still holding? What about the advance piston that is known to wear? Other than rebuilding the advance piston a rebuild is more or less a reseal job anyway. Maybe a new metering valve. These can stick and stall the engine.

 

[KrisML]

OK, been having computer issues so couldn't response till now. I found a place on ebay that sold a seal kit, but to make sure I got the correct one I called them. When talking with the guy, Larry I think, he recommended also changing the advance piston that's in the plug. Cost all of $45.00. I figure it worth a shot to try just this and he said it's doable without pulling the whole pump apart. If it still leaks or starts leaking somewhere else I'll pull it and send it out. This is the only spot I've seen it leaking from, so hoping I get lucky.

The place I got the parts from is Mylex International. They where nice to deal with and got it to me pretty fast, ordered Tuesday got it today Thursday. Probably wont get to fixing it till this weekend but I'll report with how I make out. I'll try to take some pictures too.