Instructions for Cummins Banjo Snubber CBS010

Installation for the new style electronic gauges is very different than the mechanical fuel pressure gauges. We designed and tested the orifice in the snubber using an ISSPRO standard mechanical pressure gauge. The needle bounce was less than 1 PSI at idle. With the electronic gauges, the installation is much different.

First off, the pressure sender (or a pressure gauge) cannot be installed directly on the P pump. We tested orifices down to .003 and could not make the electronic sender function correctly. The sending unit is a very fussy electronic device. According to the ISSPRO engineers, the pulsations from the lift pump have to be dampened in a different way.

This procedure only applies to 94 to 98 Cummins with the stock lift pump. From the snubber, run a 24" to 30" length of fuel rated hose to the sender. Do not use a grease gun whip hose as the hose is very stiff and will not dampen the pulsations effectively. Do not bleed the air out of the hose. Install dry. The dead air space helps to dampen the pulsations.

It is necessary to install an orifice in the sender to eliminate the gauge needle bounce. We made up several hundred stainless steel 8/32 set screws with the proper orifice in the center. Simply tap the sender for 8/32. Hold the sender vertically so chips will not fall into the sender. Do not blow compressed air in the sender, to clear the chips, as this will destroy the unit. Very gently, tap the sender onto a block of wood and the chips will fall out. Be very cautious how deep you tap the sender.

If you have purchased an EV2 electronic gauge from us and you have needle bounce with your sender, send it to us and we will install the SS orifice free of charge. If you prefer to do the job yourself, contact us and we will send an orifice to you. Also, if you purchase a new ISSPRO electronic gauge from us, we will make the mod for you. Just mention it at the time of order.

  Standard Installation of the CBS010 Snubber

Run the engine to full operating temperature. You may also plug in your block heater during the Tork Tek snubber and gauge installation. This will make it easier to start the engine later, after priming the fuel system.

The fuel inlet banjo bolt is located on the P7100 injection pump. The injection pump is on the top- forward area of the drivers side of engine. Look for the six injection lines on the top of the pump. The banjo bolt is located directly under the number six injection line.

Clean around the banjo fitting with a clean shop towel and carefully blow of any loose particles with compressed air. Wear safety glasses.

MSDS reports state that diesel fuel and biodiesel are skin irritants. Fuel will leak from the injection pump when the banjo bolt is removed. Wear rubber gloves to protect your hands.

Place a drip pan under the banjo bolt, as a cup or two of fuel will leak out of the pump. Loosen and remove the banjo bolt with a 3/4” or 19MM wrench. Make sure to remove the old seal on the back side of banjo fitting. Most times it will fall to the ground when the banjo bolt is removed. Discard old seals. Save the banjo bolt in the event you want to sell your truck at a later date.

Cardinal rule of hydraulics. Never install a seal dry. Coat the new seals with hydraulic or engine oil. The oil will make a better seal and help protect the rubber coated seals from tearing. Install one seal on the snubber and hold the other seal on the back side of banjo fitting as you screw the snubber into the injection pump.

Torque the Tork Tek snubber to 24 Ft. lbs. Too much torque can strip the threads in the injection pump. Do not over tighten.

For testing, run a 24” to 30” length of ¼” fuel rated hose from the snubber to a gauge. If you choose to supply your own testing gauge, make sure the gauge has an orifice in the base of the NPT threads. This step is for testing purposes ONLY. It is not a permanent installation. When testing or adjusting fuel pressure is done, remove hose and gauge. Plug snubber with 1/8” pipe plug.(provided) Use teflon tape on threads to prevent leaks.

Permanent installations to an in-cab gauge require a different approach. Do not run a hose from the Tork Tek snubber to the gauge. It is a fire hazard and is illegal with racing organizations. Run a #4 SS braided hose from the snubber to a Tork Tek® fuel isolator PN R7797, and one hose to the gauge. Follow the instructions carefully, otherwise you will get inaccurate pressure readings.

The fuel system must be primed before starting the engine. The lift pump is located in the lower-rear area of the engine.(drivers side) Look for black rubber bellows. Pump the priming plunger with a wood rod (36” of a broom handle works great) until you see 20 PSI on the gauge and you will hear a faint squeak from the overflow valve.

Start engine and check for fuel leaks. Engine may stumble or run rough for several seconds. This is normal. Note step number one.

Installation is complete. Save instructions for future reference.