Injector Pump - DB2 Rebuild

[broknindarkagain]

For those of you who read my other thread, you know that my injector pump is leaking. Sometimes it doesn't leak at all, and other times it looks like the truck is peeing lol. Either way, it has to be fixed. I've been digging all over the internet for the past day or so trying to find information about these pumps. The pump in my M1009 is a Stanadyne DB2-4126. I was able to source a seal kit for it locally in stock for $35 (factory Stanadyne parts) that I will be picking up in the morning. Through the magic of Google I was able to track down a factory service manual for the DB2 pump.

Stanadyne Kit Number 24370
I found it in stock at two local places
Perkins Diesel Service - Mesa, AZ - http://www.perkinsdieselservice.com/
SWDiesel - Phoenix, AZ - http://www.swdiesel.com/

You can also find it on eBay for $26 and up link

Factory Service Manual : click on thumbnail below
View attachment IP Shop Manual.pdf

I know most of you frown upon someone doing any IP work at home....but I'm stubborn and have to try it myself before I can justify farming out the work or buying a rebuilt unit. I'm sure I'm not the only stubborn one around and someone else might be able to find this information useful.

I'll update this thread tomorrow with how things are going with pictures and everything. I'll provide tips and tricks that I find make things a little easier along the way for me too.

NOTE - maybe a mod can add this to the helpful thread index?

 

[TGP (IL)]

Rebuilding the pump is not a problem, calibrating it is.
Tom

 

[gringeltaube]

... And all the info for repairing and calibrating that IP can be found in our own library: TM 9-2815-237-34, Section 2-32.



G.

 

[Warthog]

Or in the TM 9-2320-289-34 tech manual. As it was said rebuilding is the easy part. Calibration requires the proper equipment.

 

[acesneights1]

If it's just the throttle shaft seals, you can change those on the truck. Just make sure you put it back together right or it will runaway.

 

[Beyond Biodiesel]

I downloaded this manual elsewhere. I found it is an incomplete manual that describes an old version of the DB2 IP, and is not complete enough to dismantle a more recent model of the DB2.

 

[Abbylind]

If fuel is running out the back of the center gallery then its probably the throttle shaft seals (O rings) They run through the sides of the pump. Its a fairly easy fix. You'll need to take off the intake manifold to pull the shaft completely out, remove the o rings install new ones. reinstall the shaft, new gasket for the top piece and close up the pump. Reinstall the intake manifold. Lather rinse repeat....

 

[Beyond Biodiesel]

After making more progress with rebuilding 4 dead DB2 IPs using the TM 9-2815-237-34, Section 2-32, I will have up update my comment here, because I found the Factory Service Manual, posted above, was a useful addition to the TM. I still have not gotten the hydraulic head or drive shafts out, but that is all that is left.

 

[Beyond Biodiesel]

At the end of yesterday I succeeded in removing the hydraulic heads and drive shafts off of 4 of my dead DB2 IPs. They were glued on with high melting point esters (fat), so it required heat+diesel fuel+ultrasonic cleaner+pulling hard+wiggling+twisting to get them off. There were 2 broken drive shafts, so I hope to reassemble and reseal 2 of them today.

 

[Beyond Biodiesel]

An update here. The rebuilding of the DB2 injector pumps turned out to be a massive amount of work, for no useable results. I suspect that by the time one of these IPs fail, its hydraulic head is worn out, and will not make pop pressure, so I will not be doing it again.

 

[rsh4364]

So we are back to paying for a professional rebuild service,thanks for the effort and info.

 

[Keith_J]

Well, there goes my plan. The IP on my 1986 M1031 has the low speed governor retainer issue. It dies when the accelerator is blipped.

 

[rsh4364]

Yep its time. Per cucvrus advice I recently had my ip rebuilt by DCP out of Memphis with great results.

 

[cucvrus]

I know I sold my Mule M1009 to a Gentleman and it has a DCP Memphis pump on it. All my plow trucks have the same DCP Memphis pumps and the Easter Find M1008 has one also. I have nothing bad to say. I ran contaminated fuel thru a few and had less then favorable results but in the end they corrected themselves with good fuel. 500 gallons of free fuel a few years back. If I do it again it will be used only during warm weather. I drove places I never would have went that year. Free Fuel. Why NOT. Then winter came.

 

[Beyond Biodiesel]

I have been burning waste oils on a Chevy van with a 6.2L in it. I found the biggest problem was the Stanadyne DB-2 IP. It was designed with several silicon seals. Silicon seals tend to swell if alcohol is in the blend over 3%, and the even swell badly with xylene above 5%. Note: Xylene is added at 10% in stock diesel fuels.

The real problem becomes apparent after running gasoline-based waste oil blends, then followed by straight diesel fuel with xylene in it. However, if the straight diesel fuel with xylene in it is never more than 50% of the fuel blend, then I had no problems with the DB-2 IP. So, tell the rebuilders to stop using silicon seals when they rebuild the Stanadyne DB-2 IP.

 

[Keith_J]

No leaks from the IP. Only has the throttle blip dying problem from the idle speed governor. I bumped the idle set speed and can live with it but this isn't right.

From what I have seen, the only calibrations are with spring tensions. It really is a simple pump, using charge pressure to vary injected quantity.

 

[rsh4364]

I had mine rebuilt because I had loud injector knock,lot's of black smoke and engine dieing after revving.No leaks.

 

[Keith_J]

Aside from a few simple tools, this seems possible as long as spring tensions are not upset. This means leaving the leaf spring in place.

 

[rcamacho]

Old post acknowledged but good source of information on the DB2 pump. The pump is leaking from the throttle shaft on my 998 but is otherwise working to expectations. I'm debating replacing the shaft seals while on the vehicle since I have to R&R the intake manifold anyway (valve cover seal service).

Looks fairly easy to service after removing the top cover and shut off cam.

 

[rcamacho]

Started disassemby today

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