See how easy a injector cup job can be on a Diesel engine when you have the right tools. Watch from the best start to finish a C7 CAT injector cup job. This video was on a rebuilt cylinder head going on one of our Long Block assembly for stock. Normally you’ll find yourself doin this job with the engine in a truck application. Typically the customer complaint will be either fuel mixing in the coolant or coolant mixing in the fuel. The best way to verify which cup is leaking is too pressurize the cooling system with the injectors out. Definitely wanna go ahead and do all six. With the injectors out, you can also fill the cooling system back up and pressurize system to double check your work. I recommend replacing all injectors if coolant mixed with fuel and drain tanks. Definitely want to flush cooling system as well. Please like and subscribe. Thanks.