Author Topic: RACOR Filtration Systems  (Read 8304 times)

Dave Atherton

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RACOR Filtration Systems
« on: July 27, 2015, 06:45:50 PM »
RACOR Integrated Diesel Fuel Filtration Systems.  By Dave Atherton Retired Cat Mechanic.
Gentleman I have ran into several low power problems that troubleshooting has taken
me to root of problem at Racor fuel filter setup. This filter setup is before the cat transfer
pump found on many earlier Cat 3126 A, B, E, engines mounted direct from maker of Motorhome.
Where problem is located and you will know by looking at plastic tube on right side of fuel
Filter that runs vertical up and down. This plastic tube has to be full at all times running or not.
Going  back on problem, low power this tube above is 1/2 or 1/4 full of fuel, when increasing
engine rpm's. Fuel will drop very low to bottom of site glass which engine transfer pump.cannot deliver enough fuel to engine and Engine ECM will pick up on fuel and will reduce power as per
amount going to injectors. Found out talking with maker Parker Hannifin this filtration fuel
system is no longer made. But talking about operation Parker Hannifin could not be any more
clear the plastic tube on side of filter has to be full of fuel at all times. In addition to the problem
having fuel tank in front of motorhome and engine in the back leaves no room for any error
for getting fuel to the cat transfer pump To maintain fuel flow on the suction side of pump.
Going into the bigger engines C-10 and up have corrected that problem, because of more fuel
flow cat installed a electric fuel pump before the transfer pump. I have recommend to owners
with the engines below C-10 look at there fuel system very close. Most all Diesel Related Problems
From low power start at the fuel tank in front of and work back to the cat fuel transfer pump.
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Edward Buker

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Re: RACOR Filtration Systems
« Reply #1 on: July 27, 2015, 08:10:25 PM »
Dave,

While I know in the world of diesel fuel filter bowls and filtration that they are normally full with no air passing through them and that air is the devil. If you are talking about the 12963 unit with the clear plastic filter and vertical metal screen I can assure you that unit will not be full by design. I had the same questions about that unit and called Racor Tech support, they actually got hold of the Wynn designer and we had a 3 way discussion regarding this unit, how it was designed, and how it functions. If it was a closed plastic housing on the bottom of a filter then it would separate water (water settling at the bottom) and any air would flow out the top fuel exit and the housing would stay full of fuel by design with no air leaks.
 
The vertical tube with the screen is a large debris filter that was built in in the inlet stream just to supply minimal filtering so the electric purge pump did not get damaged. The fluid by flow characteristics is actually pulled apart creating a void and this is not caused by air coming in. I changed the Orings and plastic housing in mine thinking I had a leak that allowed air in and the results were the same. A new filter with less restriction actually changes the level of fuel in this housing. I think the suction pulling the fuel up out of the housing exceeds the ability of the flow coming in. If you watch closely you will see that there is actually no air within the incoming fuel stream. This is a strange design that goes against all diesel fuel supply logic and I have a hard time visualizing how this works also, but it does...strange but true.

Later Ed
 
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Dave Atherton

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Re: RACOR Filtration Systems
« Reply #2 on: July 28, 2015, 05:43:06 AM »
Ed, going into a filter setup that one would think fluid matters not at location level and kinda
buying into that idea. here is where the problem starting, low power. In most cases what causes
low power is low fuel pressure. How do we determine low fuel pressure is start at fuel tank in
front of motorhome and work back to engine fuel transfer pump. This operation is using a clear
line tied in after the racor filter start engine to see if clear line will fill with diesel fuel ( any thing
Located on suction side of cat fuel transfer cannot have any air ) starting engine let run for 10
minutes at low idle, medium idle and high idle. Again cannot have any air present in suction side
of transfer pump. Note:pulling fuel through Racor filter and seeing foam and bubbles in clear
line just before cat transfer pump one would think there is a air leak. Connect direct fuel line
from fuel tank leaving out Racor filter,same test this time no air or bubbles. Going to next level
clear line the return line on engine to fuel tank. With Racor filter connected and clear line connect
at cat transfer pump doing same test ( note cannot have any air present on return line back to tank.)
what were the results with test number one, clear line looked like foam inside and little fuel at
meduim idle and at high idle. Removed Racor filter and preformed test without filter, return clear
line full of fuel no bubbles or foam. What does this tell us with air in the return line to fuel tank.
It tell us we have very low fuel ,pressure going through the head and injectors which is causing
Low power. So nobody misunderstood about filter setup which happened to be Racor filter setup.
There is a problem that happened at present 6 times since the first of the year. Problem compounded
when party's involved had motorhome at repair shops and lots of money spent replacing parts.
After high priced repairs,  low power still present because the root of the problem was before the engine. Sorry cannot sugar coat the problem because the problem is the filter setup ( racor ). With
this said and talking with Parker Hannifin earlier, the answer to problem with any Diesel engines
There cannot be any air present on a suction side of a cat fuel transfer pump. The same thing with a fuel return line back to tank ( no air can be present ) again one filter setup maybe yes but five
more of the same the answer is no. Dave Atherton Retired Cat Mechanic


Edward Buker

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Re: RACOR Filtration Systems
« Reply #3 on: July 28, 2015, 06:28:11 PM »
David,

On my last motorhome I went through the sight glass being plumbed into the fuel lines in various places and did have an air leak at the cat filter Oring, so I am familiar with this procedure. I am positive that you have seen and been through this procedure many times and a variety of air leak sources have been repaired...nothing like hands on experience. My leak was due to a filter redesign to reduce Filter PNs, Cat made a compromise that did not work well. What used to be a dual Oring design that fit well to the housing face had become a single Oring that sat at the outer edge. That change put me down on an entrance ramp in Denver. Like you say air leaks are the devil in diesel fuel systems...

The reason for my post was to let folks on the forum know that for the Parker 12963, having the vertical plastic housing with the metal screen inside not be full while running the engine, is unique as far as visible diesel sediment bowls (which this is not) is concerned and that they should not to be alarmed by this, it is due to the design. The only time it is full is when you shut down. Unit in this link.

https://www.parker.com/portal/site/PARKER/menuitem.bb22d5a82bbb5b147cf26710237ad1ca/?vgnextoid=a2d9b5bbec622110VgnVCM10000032a71dacRCRD&vgnextfmt=default&vgnextcatid=2913342&vgnextcat=RK12963%20INTEGRATED%20RETROFIT%20KIT&vgnextdiv=687630&vgnextpartno=RK%2012963&Wtky=

These units are not without their flaws. The electric pumps are prone to fail in time, so if you cannot purge this unit it needs to be replaced. The plastic housing for the screen tends to crack with age so that should be changed at some interval, and the Orings on the plastic housing can fail. Any seepage of fuel on these units should get sourced and corrected. My diesel mechanic showed me the fuel void in the plastic housing and told me I needed a new filter unit, he said he had changed out several already for this same problem. I would guess that many of these units have been mistakenly changed over the years thinking they are an air leak source. He was not alone in assuming these units are bad.

If anyone has a 12963 unit that has a full screen housing that remains full while idling let us know. I believe the fuel pull is out the bottom and there is a column of air free fuel leaving the plastic housing as long as there are no cracks or leaking Orings.  It is just the nature of the beast by design...

Later Ed

Dave Atherton

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Re: RACOR Filtration Systems
« Reply #4 on: July 28, 2015, 07:33:59 PM »
Thanks Ed, Not trying to shoot down Racor I'm responding to low power problems after
owners have been to Cat or other repair shops and has spent lots of money and problem is
still present. Troubleshooting problem to find out what is going on there is a process us
old Mechanic's start at the beginning ( fuel tank ) and work back to engine. Cannot help
what is located in between fuel tank and motor. Having the Racor filter on 6 different
motorhomes with same problem sets off a red flag. Reason I posted message to make people
aware a problem with low power and the reason. Repair shops apparent just work on engines
and take people's money and really do not care if something works or not. This seems to
be the case in low power that have been corrected with FMCA membership via: our people
responding to the forum and again this is a team effort and I'm just one part of this team.
Dave Atherton Retired Cat Mechanic

Larry Haynes

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Re: RACOR Filtration Systems
« Reply #5 on: July 30, 2015, 03:36:12 PM »
Dave, your comments about having a lift pump:
 "In addition to the problem having fuel tank in front of motorhome and engine in the back leaves no room for any error
for getting fuel to the cat transfer pump To maintain fuel flow on the suction side of pump.
Going into the bigger engines C-10 and up have corrected that problem, because of more fuel
flow cat installed a electric fuel pump before the transfer pump."

We have an 06 Beaver with the C13 which has always seemed weaker (less performance) than our 88 Newell with a 8V92 500hp.  I replaced the Raycor primary fuel filter with a new 7125R30]Parker Racor INTEGRATED ASSEMBLY - 125 GPH. This gave me more gph from the 75 gph unit originally and it has a electric prime pump for filter changes. 

I made the change as there doesn't appear to be a lift pump prior to the engine driven Cat pump and when changing filters very hard to reprime using the hand pump on the engine.  I had thought it was weird that the fuel tank didn't have a pump to push the fuel all the way to the engine bay. 

Would adding such a pump prior to the primary fuel filter help power?

Larry Haynes
2006 Beaver Patriot C13 + 24' race trailer

Dave Atherton

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Re: RACOR Filtration Systems
« Reply #6 on: July 30, 2015, 09:02:03 PM »
Larry ,yes putting a pump before cat transfer pump would be a very good idea. Cat has a lift
Pump for a C-15 off road that would work very good and maintain a constant fuel flow. I have
Beaver member Jim Nichols that had problems with low fuel pressure. Installed a Cat pump
with filter setup and engine now responds and maintains 60 psi before cat transfer pump. Jim
had to do a little changing because off road pump was 24 volt. Cat did not plan for a fuel tank
To be located 40 feet from engine to relay on suction off cat fuel transfer pump. With a C-13
Electronic injection system constant fuel supply and pressure a must. I would suggest in giving
Jim Nichols a call or maybe on forum ( Jim is on a tour in Canada and do not know if he is on
forum or in range Internet ) Jim can tell you first hand how pump is working. Last thing install
Pressure gauge at fuel filter, 60 psi off electric cat pump leaves very little work for the Cat transfer
pump to increase correct fuel pressure in engine.
Dave Atherton Retired Cat Mechanic