2006 VNL630 D12D problems

If you have the Davco primary fuel filter with the see-thru canister, it comes two ways. With a fuel heater and without. If you have two fuel lines and two coolant hoses going to the filter, you have the fuel heater option. Hot coolant circulates through a coil inside the filter base and heats the fuel. When the gaskets on that coil go bad, coolant will leak into the fuel and pool at the bottom of the filter housing. If you open the drain valve on the bottom of the filter assy. and coolant comes out, the whole filter assy. should be changed. You can probably rebuild it, but you won't find anyone that stocks the parts. It's easier to just replace the whole thing. If you open the drain valve and clear water comes out, then you have water in your fuel tanks and it got into the secondary filter, that's why it cleared up when you replaced the filters, but came back the next day. Drain your air tanks. If coolant comes out, then your coolant leak is from a bad air compressor head gasket. If you see it wet around any of the EGR or exhaust clamps after sitting overnight, then your coolant leak is a bad EGR cooler.

 

Coolant circulates around the outside of injector cup to help keep things cool. Coolant cavitates (eats) through copper cups eventually. Coolant then gets into fuel stream circulating throughout head (feed and return) Fuel is diluted with coolant, along with small amounts of air, to cause hard starts and rough running. Fuel return to tanks is how coolant gets in there. Others may explain more clearly.

 

It does take special tools. If you search the forum there was a good post about 6-8 months old that someone posted the tool kit part #. Not the easiest job to do, even for the pro's. Might be money well spent having it done professionally.

 

Silver Dollar if you would like the part numbers for the tools as well as a rundown on how to do the job, let me know.

 

it's a whole procedure on how to do this i would really suggest doing yourself either better take to a volvo shop to do it being that it requires special tools and someone with knowledge of the procedure as far as money goes you are not looking at anything really crazy cup kits are about 35 each so thats around 400 for parts with a new gasket and maybe around 1200 for labor so it's not anything really horrible, the good thing with d12 is that you do not need to change injectors and this is the big plus.

 

@nasriza delivers another nugget, yet again...thx