Common Issues for a DD15

If you own or drive a Detroit DD15 Diesel Semi Truck, let’s talk about some common issues they have. We all know that if it’s a diesel, then it’s going to leak oil. And leaking oil can lead to low oil pressure and a dirty engine compartment. I want to go over some quick tips to help you troubleshoot your 18 wheeler so you can do the repairs yourself, or get it in for a service.

Low Oil Pressure

After reaching 500,000 miles, a common issue with a DD15 is low oil pressure. Repair shops will often recommend replacing your oil pump and mains. While it is a good idea to have the oil pump and mains checked out, replacing them is often not required. The true issue is most often caused by faulty O-rings in the suction tube that brings the oil up from the bottom of the oil pan. The O-rings dry out from excess heat and get brittle and lose their seal. It’s an easy fix to drop the oil pan and replace all the O-rings in the oil slump. Put everything back together and your oil pressure will be back up.

Oil Leaks

Here are a few common sources for oil leaks at around 500,000 miles:

  1. The gasket between the Fuel Pump & Air Compressor
  2. Reseal Water Pump & Oil Cooler Housing
  3. Lower Rocker Box Seal on the Head

Oil Weight

Always use the correct oil weight as recommended by Detroit (15w 40). Using heavier weights during the wintertime makes the oil pressure higher and can cause more oil leaks in your engine.

Crank Case Filter

The crank case filter is located in the engine compartment on the passenger side of the vehicle. It is an assembly item and is not serviceable. It is recommended to have the crank case filter replaced at 500,000 miles or if it becomes clogged or starts to leak oil.

Fuel System Tips for Your DD15

Make sure that every time you get your oil changed and open up your fuel system, use only Detroit approved priming tools. Also note that Detroit does not recommend using any kind of starting fluid on these newer DD15 engines.

Schedule Service for Your DD15

If you are looking for honest and reliable Diesel Repair, our team of mechanics is here to help! We routinely handle: Factory Scheduled Maintenance, Heavy Duty Truck Tires, and Heavy Duty Truck Repair. We know time is money, so our certified technicians focus on getting you back on the road in a timely and affordable manner. Give us a call at (972) 225-3017 or visit us online today.

Your One Stop Shop

TAT Express Inc.
4140 Langdon Rd.
Dallas, TX 75241