DT 466/530 oil supply manifold gasket

Clark · April 8, 2009

Anyone whos worked on these knows that the oil supply manifold, has a habit of leaking, usually when not properly torqued. Up until today, the worst Id ever seen was just a little sludge.

Background- The truck is a 7400 garbage truck with a DT530 that came in for a hard start/no start and low power. I found that all 6 injectors buzzed quietly or not at all, and recommended 6 injectors. Put the 6 in, and the truck starts fine, runs better, and has better power. Fixed... no. Let it sit for about 45 minutes to work on ABS, and it wont start. I find its intermittently sucking air, alot of air. The inlet quick connect on the fuel filter module had worn out its female connector side. After I replaced both the male and female ends, everything was great. Thoroughly test drove it, and had no problems.

That was a couple weeks ago, and it came back today for a hard start/no start, again. The first thing I noticed was that the supply manifold was soaked with wet oil, and I couldnt remember it leaking the last time it was in. I found that It was leaking bad enough to actually be dripping oil (leaking down over night = hard start). Pulled everything apart, found no apparent damage to the gasket, and both of the surfaces were flat. Put it all back together and everything works great.

So basically, has anyone ever seen one of these gaskets fail that badly, enough to actually cause a hard start? It was definitely a first for me, and for everyone in my shop.

International Tech · April 8, 2009

yes Its actually quite common. The oring on the elbow for the oil supply line leaks quite a bit too. Ive seen the ICP sensor cracked and leaking a couple times too.