Fuel leak at Hyd .head

[WVFDTX]

Hello everyone. Im with a rural V.F.D. in Texas & we have a small (I hope) problem with our 2.5 Ton Duce. There is a fuel leak at the Hyd. head assy. & the Injection pump housing. It started as a few drips and escalated into a spray. I have downloaded the TM for the pump & still have a few questions. As far as I can tell, the pump assy. is an early code G. The manual states instructions with the pump removed from the truck. Can this leak be repaired on the truck? What do I need to expect when the head is removed from the pump? Is it a gasket or O-ring? Where to buy the part? This is one of our most used trucks, & removing it from service for a long period (more than a day or 2) is something I really need to avoid. It is a 1969 2.5 ton 6x6, M35A2C with a CMC LDT-465 Multifuel engine (we only rune diesel). I have included a pic of where the leak is. Any help on this would be awesome.

 

[dutchguy]

I will offer my $.02. I apologize if this sounds condescending, don't mean it that way. The round piece with the fuel lines coming out the top is the Hydraulic Head. It is held onto the Fuel Injection pump with four nuts, one of which is right next to your red arrow. The joint between the Hydraulic Head and the IP is sealed with two O-rings. Top one is a -230, lower one is a -227. If the fuel is spraying out at the joint between the hydraulic head and the IP the top one could be bad. Or, there may be a crack in the head. I just finished with a Hydraulic Head replacement. If you only have two days, you might have to get some parts around. Here's what could complicate things:
- Fuel lines rusted into nuts, or head (I had to cut two of mine). If you only had two days, I'd order a full new set.
- Hydraulic Head cracked (expensive, will take a few days to get).
- Lots of threads in the forum about HH removal, and lining the red/notched tooth on the HH drive gear with a pointer, perfect alignment is the key here. Do not pay attention to the engine timing marks, or turn the engine while the HH is off the pump.
- You will also want a -013 O-ring for the fuel control shaft, and pay particular attention to the small pin in the end of this shaft. Presence and alignment when reassembling are key.
Hope it is only the O-ring! Good luck.

 

[Floridianson]

If it is leaking from between the HH and the base if the IP then I would guess one or both O rings on the head have let go. Give me your address to ship and I will overnight the three O rings that need to be replaced no charge. I also sent you a PM with my number and can explan faster how easey they are to replace. Also start today putting some PB blaster on the threads of the injector lines at the head.

 

[WVFDTX]

Thank you very much for the replies & a huge thanks to Floridianson, for the donation of the O-rings and help for the department. Already have PB blaster working. While I await the parts i'll be reading threads on the R&R of the head.

 

[RAYZER]

Also, check to make sure that this didn't leak fuel into your crankcase and contaminate your engine oil.

 

[Floridianson]

Good thought Ray.

 

[WVFDTX]

Got some weather yesterday so i took the plunge & pulled the truck from service for the repair. Went w/out a hitch, new o-rings did the trick. No leaks & I just thought the truck ran great before, starts w/out using ether & runs great. Found a lot of trash in the HH ports, but cleaned out easy enough. No fuel in the oil, but she got a change any way (thx Ray). Thanks for the help guys!

 

[dutchguy]

Nice work, that's great. Glad to hear that you didn't need a hydraulic head.