Cummins 450C 6CTA – Changing Racors and Secondaries

[Alex F]

I’ve done some research and compiled the list of steps required for servicing Racors and Secondaries. Can some experienced diesel guys do a quick visual and point out if I missed anything important? I would really appreciate it.How To Change Racors and Secondary Fuel Filters

Parts and Tools
Bucket to catch fuel spillage
Rags
Oil absorbing pads
Garbage bags
New Racors for mains and genny
About 1gal of clean diesel to top off the Racors after new ones are in place
Piece of wire or rope to tie the old Racors so the fuel is drained back in the baul
Fuel filter wrench

Taking OFF Old Racors
1. Shut Off fuel valves (Not sure how much good it did as the fuel ran for a long time).
2. Put 2 gallons bucket and fuel pads under the Racors to collect spillage. Get the garbage bag ready as well.
3. One trick I have learned (other than 2 gallon zip lock bags) is to tie a rag around the Racors housing prior to opening the "T" handle. The rag will catch the fuel and help to keep things clean. On my boat turning the valve handle to off and using the rag, no fuel is spilled.
4. Pop the top off with the T-handle and then pull the filters out and rest them on the top of the housing such that the filters drain their excess fuel back into the housing. After about 5 minutes I wrap the old filters in some oil absorbing pad and stick them in the trash.

Installing New Racors
5. Put new filter cartridges back in and drain a little fuel (1/4 cup?) out the bottom. To drain water and sediment, I had to loosen the brass bolt at the base of the heat shield enough to drain off the impurities at the bottom of the clear Racors bowl. If this is your application (no petcocks) be very careful that you do not over tighten the brass bolt that holds the heat shield in place. I over tightened the bolt during annual services last fall and cracked the clear plastic Racors bowl. This then caused a slow fuel drip into the engine room.
6. Top off the Racors with fresh diesel
7. Put a new o-ring on the lid and on the t-bolt, oil the o-rings with motor oil.
8. Put the lid on hand tight...no wrenches are needed.

Taking OFF Old Secondary Fuel Filters
9. Shut Off fuel valves (if there're any by the secondary filter).
10. Put a small bucket and fuel pads under the filter to collect spillage. Get the garbage bag ready as well.
11. Make sure that old o-ring is OFF the mount base.

Installing Secondary Fuel Filters
12. Put some oil on the new filter o-ring, place the new filter back on and tighten it by hand. (no need to add fuel as it's bypassing the filtration process and adds risk of getting very small particles of debris in the fuel and causing problems).
13. When you are done, check to be sure all fuel valves are open on both the fuel manifold and Racors if you have one there.
14. Final check:
A) New Racors is in place and the lid is tightened.
B) New secondary filter is installed.
C) All fuel valves are opened.
15. Now it's time to pump the fuel back in the system and chase all the air out. Start pumping for at least 30sec, you'll feel some resistance, but need to continue to pump until hear the consistent squeaking noise. This may take about 1+ min of constant pumping.

Starting The Engine(s)
16. Start up the engines by advancing the throttles slightly...when the engines start, set the rpm's at about 1000 rpm and let them idle there until they smooth out. This will also purge any air in the system without killing an engine. Incidentally, use this same starting procedure when you change the secondaries as well (if done at different time).
17. Before shutting the engine, rev it once or twice to make sure it spills all the air out of the system.

 

[fwebster]

Alex......you might be over thinking this.

I am jammed up this weekend and will be traveling next week, so I can't re-write the procedure, but here are some points you need to think thru:

1. Use the yellow handle valve between the Racors to shut off the fuel flow.
2. The fuel should be a little below the top of the Racor body so it isn't going to make a big mess, as long as you sut off the fuel at the Racor instead of the fuel manifold.
3. Leave the T-handle on the lid in place and remove the drain plug in the bottom of the filter first, not last as you have it in your procedure. The T-handle creates an air lock and the fuel escaping thru the sump drain is controllable. If you remove the T-handle first, you will be like the little boy trying to stick his finger in the dike. Doing it my way and draining the bowl thru the sump drain washes a lot of the caught debris out of the filter body.
4. When the bowl is empty, put the new element in the filter body, then reinsert the drain plug but do not over tighten and be sure you hold the fitting that the plug screws into to prevent it from turning.
5. When you are done and ready to crank the engines, keep one hand on the throttle and work it to keep the engine running at 1000-1200 rpm. When the air is purged, the engine will smooth out and idle normally.......there is no need to rev a diesel to purge the air......when the air is gone, the idle smooths out, or, if you induced a lot of air or failed to purge it with the pump, the engine will die and you have to start the purging process over from the Racor forward.
6.And reving a cold diesel is never a good practice.

Good luck with it.............

 

[Alex F]

Frank,

Thanks for your tips. I worked on this today and whooooooo very "interesting" task for the first timer. It looked like the bauls were never cleaned as the bottom bolts were very tight. My boat has single racors on the mains, so I had to find the hidden valves. Strbd side went fine, but on the port side I turned the wrong valve. That was fun......the fuel keeps coming and coming....LOL. I've waited until I drained about 1.5gal and then I said to myself, that can't be right, I must have turned the wrong valve. This is when I descovered that my genny feeds from both tanks. So, the port valve for the engine was well hidden and hard to get to.

The biggest part of the fun was to clean the bauls. When I took the racor out I saw that there's no way to get to the baul without taking it apart due to the middle part blocking the access. To my luck Robert was around to give me a cleaning tip, which is fill and flash the baul several times until it's clean. The trick worked fine to get the baul about 90% clean (even thought the baul looked clean there was still good number of stuff that came out). The process worked well, but it's very time consuming.

I did the secondaries at the same time and used manual priming pumps, it worked well.

Do you have a tip on a different way to clean the bauls?

Thanks,
Alex.