HEUI Pump Post-Filter

[Gadget Man]

George,


What does the difference in pulsation psi mean to a layman like me? Thanks!

[discovery39s]

Gadget,
Great question. When the pistons in an axial pump, HEUI, phase between drawing oil in and then displacing it the pressure builds, due to resistance in flow, then drops on that piston until the next piston discharges more oil. Pulsation occurs in between discharge of each piston.
A steel line has near zero expansion and contraction so the pressure spikes, or phasing, is more pronounced and is witnessed on a gauge. (if you have seen one video from Adapt Ape, the intro shows a hydraulic gauge bouncing all around, that's phasing)
A hose on the other hand expands and contracts, thus "smoothing" the pulsation and would be witnessed on a gauge. Adversely, you would hear or feel the pulsation in a hose verses a tubing. You may "hear" a buzz in a hose or harmonics.

My theory is that smoothing phasing/pulsation provides more consistent oil pressure in the injectors rather firing an injector on the low side of a phase verses the high side. This is only my theory however it does reduce low/high spikes on the oil side and is proportional to the fuel pressure on the injectors. So, lets say it increases pressure consistency by 8%. Then so is the fuel pressure coming out of the injector orifice into the combustion cylinder.

Hope that provides some clarity.
George

[Gadget Man]

Thanks for explaining that to dumb people like me George. Makes perfect sense now.

[discovery39s]

Originally Posted by Gadget Man

Thanks for explaining that to dumb people like me George. Makes perfect sense now.

Gadget,
I'm sure I would be brain shy of whatever your profession may be. Not a matter of "dumb", only the fact we have a great group of members that share some great knowledge we have accumulated over our years.

Have a great day,
George

[shajoe44]

Has anyone installed the IFS Filter system on a 2006 Cat C9 400HP. I was wondering install time and ease of installation on this particular engine. Thanks

[DIronworks]

Hi all, diesel newbie here. Wife and I acquired a 2006 Freightliner FS65 school bus with a C-7 that we plan on turning into an RV. I have looked at both the pre and post filter systems for the HEUI pump. I am wondering if it is overly redundant to do both. I read George's earlier post comparing to the whole house filter system and that makes sense, but contemplating what two ounces of prevention are worth. Any thoughts?

[Journey cat]

Your only thought should be . That if your Heui goes south . And you have a tode . You can drive down the road . Purchase a new pump and be on your way . Rather than be spending weeks waiting to get your rig fixed . At a much greater price

[Cat]

Originally Posted by DIronworks

Hi all, diesel newbie here. Wife and I acquired a 2006 Freightliner FS65 school bus with a C-7 that we plan on turning into an RV. I have looked at both the pre and post filter systems for the HEUI pump. I am wondering if it is overly redundant to do both. I read George's earlier post comparing to the whole house filter system and that makes sense, but contemplating what two ounces of prevention are worth. Any thoughts?

Good question. One filter the prefilter is suppose to help prevent a heui pump failure. The post filter is to prevent damage to the injectors and the contamination of the oil rail if you fail a heui pump. My personal and personal work experience. Is the prefilter will not prevent most heui pump failures.

I would highly recommend the post filter. Especially since you have a engine/heui pump with a lot miles? already on it. But there is no reason not to install the prefilter if you wanted the extra protection. Adding the prefilter is not overly expensive. So its really up to you. Safe Travels

[discovery39s]

Originally Posted by Cat

Good question. One filter the prefilter is suppose to help prevent a heui pump failure. The post filter is to prevent damage to the injectors and the contamination of the oil rail if you fail a heui pump. My personal and personal work experience. Is the prefilter will not prevent most heui pump failures.

I would highly recommend the post filter. Especially since you have a engine/heui pump with a lot miles? already on it. But there is no reason not to install the prefilter if you wanted the extra protection. Adding the prefilter is not overly expensive. So its really up to you. Safe Travels

Not to discount Cat's statement at all. However, its not a matter of the component cost for the pre-filter, it's the cost to install if you do not do it yourself. IF the compressor didn't need to be removed then the cost would be minimal. If you do it yourself, bring a lunch (dinner too). I've completed this install, NO FUN.

Just the facts!

[rbh44]

Not sure where to post but here goes.We have a 2004 Newmar DP KS Freightliner 300 hp Cat c7.started losing power so thinking need to replace fuel filter.We did this 3 times on an 1,100 mi.trip.Still haven't the power on acceleration we should.I've read about the Heui pump & secondary fuel filter so where is the secondary fuel filter located on this engine? This isn't a man asking but his wife,just trying to help before going to the Cat repair on Wednesday. Should add that the top speed we could get was not over 50 mph.Thanks in advance.

[Cat]

Originally Posted by rbh44

Not sure where to post but here goes.We have a 2004 Newmar DP KS Freightliner 300 hp Cat c7.started losing power so thinking need to replace fuel filter.We did this 3 times on an 1,100 mi.trip.Still haven't the power on acceleration we should.I've read about the Heui pump & secondary fuel filter so where is the secondary fuel filter located on this engine? This isn't a man asking but his wife,just trying to help before going to the Cat repair on Wednesday. Should add that the top speed we could get was not over 50 mph.Thanks in advance.

In most cases it is mounted on the engine up toward the top of the engine in the intake manifold area. If you supply a engine serial number will try to look up how the engine was equipped when it left the factory.

[rbh44]

Originally Posted by Cat

In most cases it is mounted on the engine up toward the top of the engine in the intake manifold area. If you supply a engine serial number will try to look up how the engine was equipped when it left the factory.

Thanks,I'll have to get under MH & find serial #.I do have the Freightliner sr# on inside kitchen cabinet.Hubby not able to get under there today.I'll try & find it .Thanks

[rbh44]

Originally Posted by Cat

In most cases it is mounted on the engine up toward the top of the engine in the intake manifold area. If you supply a engine serial number will try to look up how the engine was equipped when it left the factory.

Wasn't able to get under MH but did find additional info.by accident while cleaning kitchen cabinet.Here's what I found maybe you'll know what to do with it.
Mfg.Oct.2003,Vin#4uzzaahdc64cm91906-Chassis md.XC-Cat C7 330HP-RPM 2400
Engine#-KAL12197-Trans#-6510459136 Allison 3000MH-
There are more #'s for Axles
We have an appt.for this Wed.at the Cat repair shop here in south Texas where we usually spend time in winter months.These Golden Years aren't always easy but we'll survive.Thanks to all for the help.I'll surely post what we find out.Fingers crossed my SS check will cover the repair.

[Cat]

Originally Posted by rbh44

Wasn't able to get under MH but did find additional info.by accident while cleaning kitchen cabinet.Here's what I found maybe you'll know what to do with it.
Mfg.Oct.2003,Vin#4uzzaahdc64cm91906-Chassis md.XC-Cat C7 330HP-RPM 2400
Engine#-KAL12197-Trans#-6510459136 Allison 3000MH-
There are more #'s for Axles
We have an appt.for this Wed.at the Cat repair shop here in south Texas where we usually spend time in winter months.These Golden Years aren't always easy but we'll survive.Thanks to all for the help.I'll surely post what we find out.Fingers crossed my SS check will cover the repair.

KAL12197 did not appear to have left the Caterpillar factory with a fuel filter mountings on it. What that means is the chassis builder would have put their fuel filter mountings and filters on. That also means you could have one filter on your coach or two filters. If you have two filters one would be one that filtered out large contaminations 20micron and larger and may also be a water separator. The secondary filter would be one that filters out 2-4micron and larger. If you only have one filter it needs to be able to filter out the 2-4 micron material. This is where you can in to trouble "will fit" filters won't necessarily be the filter that filters out the 2-4 micron and larger contamination. If you only have the wrong filter on that filters 20micron and larger it will do serious damage to the fuel injector system.
I would take to a CAT house and have them check the engine for codes etc. Good luck. Let us know what you find out whats wrong. Safe Travels