How to Replace the Oil Supply Tube on a Cummins QSX15 Engine

The Cummins QSX15 engine is a powerful and reliable engine commonly used in heavy-duty applications such as construction equipment, mining trucks, and marine vessels. One crucial component of the QSX15 engine is the oil supply tube, which delivers oil to various parts of the engine to ensure proper lubrication and cooling. Over time, the oil supply tube may become worn or damaged, leading to oil leaks or engine performance issues. In this article, we will discuss how to replace the oil supply tube on a Cummins QSX15 engine.

Before beginning the replacement process, it is important to gather all the necessary tools and materials. You will need a socket set, torque wrench, new oil supply tube, gaskets, and any other replacement parts specific to your engine model. It is also recommended to have a service manual or technical guide for reference during the replacement process.

API 5ct L80 Casing tubingDimensions and Masses for standard Casing and for Casing threaded with
API Round Thread and Buttress Thread
Labels a							Calculated Mass c
			Nominal linear Mass T& C b,c	Wall thick– ness				em, Mass Gain or Loss Due to End Finishing d
		Outside diameter			Inside Diameter	Drift Diameter	Plain- end	kg
								Round Thread		Buttress Thread
							wpe
		D	kg/m	t	D	mm	kg/m	Short	Long	RC	SCC
		mm		mm	mm
1	2	3	4	5	6	7	8	9	10	11	12
4 1/2	9.5	114.3	14.38	5.21	103.88	100.7	14.02	3.64	—	— 4.53	— 1.12
4 1/2	10.5	114.3	15.73	5.69	102.92	99.74	15.24	3.33	— 3.61	4.32	0.91
4 1/2	11.6	114.3	17.38	6.35	101.6	98.42	16.91	3.18	3.35	4.07	0.6
4 1/2	13.5	114.3	19.87	7.37	99.56	96.38	19.44	—	3.53	3.64	0.24
4 1/2	15.1	114.3	22.69	8.56	97.18	94	22.32	—
5	11.5	127	17.19	5.59	115.82	112.64	16.74	4.32	— 4.85	— 5.38	— 1.24
5	13	127	19.69	6.43	114.14	110.96	19.12	4	4.51	4.99	0.61
5	15	127	22.69	7.52	111.96	108.78	22.16	3.71	4.52	4.4	0.22
5	18	127	27.19	9.19	108.62	105.44	26.7	—	3.45	3.76	–0.62
5	21.4	127	32.13	11.1	104.8	101.62	31.73	—	3.15	3.42	–0.96
5	23.2	127	34.76	12.14	102.72	99.54	34.39	—	2.99	3.23	–1.14
5	24.1	127	36.15	12.7	101.6	98.42	35.8	—
5 1/2	14	139.7	20.91	6.2	127.3	124.12	20.41	4.6	— 5.26	— 5.71	— 0.87
5 1/2	15.5	139.7	23.48	6.98	125.74	122.56	22.85	4.36	5.31	5.41	0.58
5 1/2	17	139.7	25.72	7.72	124.26	121.08	25.13	4.14	4.5	4.84	0.45
5 1/2	20	139.7	30.05	9.17	121.36	118.18	29.52	—	4.37	4.31	-0.52
5 1/2	23	139.7	34.05	10.54	118.62	115.44	33.57	—	—	—	—
5 1/2	26.8	139.7	40.15	12.7	114.3	111.12	39.78	—	—	—	—
5 1/2	29.7	139.7	44.47	14.27	111.16	107.98	44.14	—	—	—	—
5 1/2	32.6	139.7	48.74	15.88	107.94	104.76	48.49	—	—	—	—
5 1/2	35.3	139.7	52.8	17.45	104.8	101.62	52.61	—	—	—	—
5 1/2	38	139.7	56.82	19.05	101.6	98.42	56.68	—	—	—	—
5 1/2	40.5	139.7	60.64	20.62	98.46	95.28	60.55	—	—	—	—
5 1/2	43.1	139.7	64.41	22.22	95.26	92.08	64.38	—
6 5/8	20	168.28	29.76	7.32	153.64	150.46	29.06	5.58	6.23	6.35	0.89
6 5/8	24	168.28	35.72	8.94	150.4	147.22	35.13	4.42	5.48	5.52	0.68
6 5/8	28	168.28	41.67	10.59	147.1	143.92	41.18	—	4.73	4.71	–0.75
6 5/8	32	168.28	47.62	12.06	144.16	140.98	46.46	—	4.73	4	–1.46

To start, ensure that the engine is cool and disconnected from any power source. Drain the engine oil and remove the oil filter to access the oil supply tube. Next, locate the oil supply tube on the engine block and carefully remove any mounting bolts or brackets securing the tube in place. Take note of the orientation of the tube and any attached components for reassembly. Once the oil supply tube is free from its mounting points, gently pull it out of the engine block. Inspect the old tube for any signs of damage or wear, such as cracks, corrosion, or leaks. If the tube is damaged, discard it properly and clean any residual oil or debris from the mounting area. Oil field with 2 7/8″ -13 3/8″ pH6 Vm Thread CasingBefore installing the new oil supply tube, apply a thin layer of engine oil to the o-rings or gaskets to ensure a proper Seal. Carefully insert the new tube into the engine block, aligning it with the mounting points and attached components. Secure the tube in place with the mounting bolts or brackets, ensuring that they are tightened to the manufacturer‘s specifications. After the new oil supply tube is installed, replace the oil filter and refill the engine with fresh oil. Start the engine and check for any leaks or abnormal noises. monitor the engine for a few minutes to ensure that the oil supply tube is functioning properly and delivering oil to the necessary components. In conclusion, replacing the oil supply tube on a Cummins QSX15 engine is a straightforward process that can be completed with basic tools and mechanical knowledge. By following these steps and taking proper precautions, you can ensure that your engine continues to operate at peak performance and efficiency. Remember to consult a professional technician or service manual if you encounter any difficulties during the replacement process.