How do I know if my PT pump needs to be run on a test bench? If your Cummins engine shows symptoms like hard starting, black smoke, poor fuel economy, or unstable idle, but all basic checks (filters, lines, throttle linkage) come back clean, the PT pump itself may be out of calibration. A test bench can measure flow rate across different throttle and speed settings. If pump output doesn't match Cummins specifications, it needs bench recalibration or internal repairs. https://www.cq-longshine.com/cummins-pt-test-bench

What is a Cummins PT test bench used for? A Cummins PT test bench is a specialized diagnostic stand designed to test, calibrate, and troubleshoot PT (Pressure-Time) fuel systems. Unlike common rail or unit injector systems, PT fuel systems rely on fuel pressure and injector open time to meter fuel. The test bench simulates engine operating conditions—such as fuel temperature, pressure, and flow—to verify components like the PT pump, injectors, and AFC (Air-Fuel Control) devices before they go back on an engine. https://www.cq-longshine.com/cummins-pt-test-bench

What parts are included in a Cummins injector cup replacement kit? A proper injector cup kit contains more than just the metal sleeve. A complete kit typically includes: The injector cup (sleeve) – Usually made of hardened steel or stainless steel. Upper and lower O-rings (or copper seals) – These seal the cup to the cylinder head coolant passages. Never reuse old seals. Installation lubricant – Required to prevent O-ring cutting during insertion. Retaining compound (sometimes) – Used on threaded cup designs to prevent loosening. Some engines (like older N14 models) use a threaded cup with a copper sealing washer instead of O-rings. Always verify your engine serial number (ESN) before ordering because cup designs changed multiple times over production years. https://www.cq-longshine.com/cummins-injector-cup

Can I replace a Cummins injector cup without removing the cylinder head? Yes, in most cases you can. Many Cummins engines (including the ISX, ISM, and N14) allow injector cup replacement with the cylinder head still on the engine. Specialized tooling is required: Cup puller / installer kit – A threaded puller extracts the old cup without damaging the head bore. Cup driver / seating tool – Ensures the new cup is seated to the correct depth. Seal installation tools – Protects new O-rings or copper seals during installation. However, there are exceptions. If the cup has spun in the head, cracked the head casting, or if the bore is severely corroded, the head must come off for machining or replacement. Always inspect the cup bore for pitting before installing a new cup. https://www.cq-longshine.com/cummins-injector-cup

How do you perform a basic PT injector flow test on a bench? A typical injector test procedure: Mount the injector in the bench's firing fixture Connect the bench to a calibrated PT pump (or use the bench's internal pump) Set test fluid temperature to 100–110°F (38–43°C) Run the pump at a specified speed (e.g., 500–600 RPM for injector testing) Fire the injector for a set number of strokes (often 500 or 1000) Measure the fuel collected in a graduated cylinder Compare to factory specs – for example, a Big Cam IV injector might require 28–32 mL per 1000 strokes Adjust metering orifice or plunger travel as needed, then retest https://www.cq-longshine.com/cummins-pt-test-bench

Can you calibrate a PT pump or injectors without a test bench? No – not properly. While you can mechanically adjust injector plunger travel on the engine (using a dial indicator for overhead adjustments), true calibration requires a test bench because: Fuel flow must be measured at multiple RPM points Injector-to-injector variation must be balanced within tight tolerances (often ±2–3 mL per 1000 strokes) Governor breakpoints and droop require dynamic testing AFC response needs controlled pressure ramping Field adjustments can get an engine running, but only a test bench ensures performance, fuel economy, and emissions compliance. https://www.cq-longshine.com/cummins-pt-test-bench

What Are the Signs of a Failing or Leaking Injector Cup? An injector cup failure is a serious event that can lead to catastrophic engine damage if not caught early. Because the cup separates the fuel system from the cooling system, leaks can go in two directions. Here are the tell-tale signs: Sign #1: Coolant in the Oil (The Milky Oil) This is the most common and devastating sign. If the O-rings or the cup itself fail, coolant can seep past the injector and drain down into the crankcase. Visual: The oil on the dipstick will appear milky, foamy, or chocolate-milk colored. Result: Coolant destroys the lubricating properties of oil, leading to rapid bearing failure. Stop the engine immediately. https://www.cq-longshine.com/cummins-injector-cup

What is a Cummins Injector Cup and What Is Its Purpose? The Cummins Injector Cup (often referred to as the injector sleeve or injector tube) is a precision-machined cylindrical component that is pressed into the cylinder head. It serves as the socket that houses the fuel injector and creates a critical barrier between the fuel system and the cooling system. What does it look like? It is a brass or steel tube with a precision-machined bore that matches the outside diameter of the injector. It has a flanged top that seats against the cylinder head and a tapered or radiused bottom that extends into the combustion chamber area. https://www.cq-longshine.com/cummins-injector-cup

Which model-year transmissions will bolt into a 2017 Cummins? Answer: For direct interchangeability: 68RFE: Typically compatible from 2007.5 to 2018 Ram 6.7 Cummins trucks Aisin AS69RC: Generally compatible from 2013 to 2018 Ram 3500 Cummins trucks However, even if the transmission physically bolts in, electronics, TCM programming, and wiring connectors must match for proper operation. https://www.cq-longshine.com/blogs/what-year-model-transmissions-are-interchangeable-with-a-2017-6-7-cummins

What transmission came in a 2017 6.7 Cummins Ram? Answer: A 2017 Ram 2500/3500 with the 6.7L Cummins came with either the 68RFE 6-speed automatic (most 2500s and some 3500s) or the Aisin AS69RC 6-speed automatic (commonly in higher-trim 3500 trucks). The transmission choice depends on the truck’s GVWR and trim level. https://www.cq-longshine.com/blogs/what-year-model-transmissions-are-interchangeable-with-a-2017-6-7-cummins