Mack eup leaking

[Chris_poyner]

Hey guys, been reading on the forums for a few days and just joined. We just bought a 1999 mack dump truck with a 350 e7. We're having a fuel leak on the number 6 eup which looks like the funnest one to work on due to the downpipe. Im very mechanically inclined but have never messed with macks. Is there anything i need to look out for when pulling out an eup? Can you get the gaskets from mack or do they try to sell you a whole new eup? Ive already heard about the problems with the eup snapping bolts. Is there a remedy for that or just replace with new bolts everytime?

[Challenger]

You can buy EUP oring kits. Replace EUP mounting bolts everytime. Always leave one eup bolt loose while removing the spring tension of the eup. When the eup "pops" loose the bolt will keep it in the hole and not flying through your shop.

[turckster]

Remove the fuel return fitting in the block to drain the fuel galley. As stated by Challenger, leave one bolt in screwed out half way or so. When installing the EUP w/new o-rings (o-rings in top and bottom grooves-don't use the middle any more), slide in the EUP, rotate the engine using a turning tool until you notice the EUP is at the bottom of its travel(bottom of the lobe). Slowly and evenly tighten mount bolts to draw the EUP down evenly. Torque the bolts to 60-65 ft/lbs. Lube the o-rings and bolt threads w/fresh engine oil.

Bleeding air out of the fuel galley can be a pain in the tush. What has worked for me is to loosen all the inj. lines at the EUP's, pump up the fuel primer, when fuel flows out of each EUP that looks clear-not airy, tighten inj. lines(torque to 25 ft/lbs). Hope that helps, good luck.