Sounds like the "O" ring seals under each pump are either missing or dried up & hard like a rock & won,t seal the fuel anymore. The part number is 2A3307 from Cat.Each pump will have to be removed & change that seal & don,t mix up the plungers & barrels of the pump but keep them matched up with each other as they were hand fit at the factory. When going back each pump gear has a notch mark on it so line that up with the mark on the rack bar as they go back down in.You can line the gear & plunger up to the rack & hold it in place through the side plate opening & then slide the barrel or main part of the pump down over it while holding the gear & plunger firm in place & they should be in time now ok.Work the rack after you get the pumps bolted back down to make sure it,s free & no binding. Turn the fuel off at the main tank before removing the pumps so fuel won,t run out of the hollow tubes on top the injection housing. Forgot to say these "O" ring seals set down over these hollow tubes sticking up out of the inj. housing so just slip them down over before you install the pump assemblies. Make sure the old seals are removed from the under side of each pump & the pump will have a half moon indented cup that sets down over the seals.