Tools/spares to carry?

[john brunson]

Dave,

I have gotten away with ATF on two huge Cummins engines and one large Mitsubishi engine both with electronic engine controls... My plan is to follow the BCS guys' instruction using diesel.... It just leaves me kinda insecure... The last Cat I primed was on a large older dozier and there was no prime pump... Operator ran the thing bone dry ....After a day of cussing that beast, I installed a small electric pump and loosened the banjo fittings on fuel rail.... After a few minutes, she quit slobbering bubbles and we managed to get going.... Call it fractured trust I guess...  There is no prime pump manual or electric on this beaver... Has two remote mounted filters...Gonna have to bite the bullet and develop a recipe for priming this one...that way I will have a better chance if I need to do it on the roadside...

[Dave Atherton]

John, the Cummins electronic engine and fuel system is different than the Cat electronic
engine in many ways. Getting air from fuel system on the Electronic Cat engine with/out
primer pump has a bleed plug on secondary fuel filter base ( top corner ) all that is needed is loosen
Bleed plug one turn and turn over engine about 15 seconds and tighten bleed screw. This is
correct way to bleed a Cat electronic engine. Point to pass along Cummins engine primary
and secondary fuel filters are ( 10 to 15 micron primary fuel and 10 micron on the secondary
fuel ). Cat fuel system primary fuel 10 micron and the secondary filter is 2 micron which is
a must on a cat engine.  Dave Atherton Retired Cat Mechanic

[Dick Simonis]

John, would it be practical to replace the primary filter housing with one that has the built in prime pump??  Racor 700 or the FR series like our newer models??

[Gerald Farris]

John,
Personally, I would not have a coach without a priming pump in the fuel system. A priming pump makes changing the fuel filters so much easier, and it eliminates the problems that can be created by pouring unfiltered fuel into the fuel system. The unfiltered fuel issue is not a problem with the primary filter because any fuel that is poured into it is filtered by the 2 micron secondary filter, but any fuel that you pour into the center hole on the secondary filter will travel into the injection system unfiltered. The fuel that you use to prime the filter may look clean, but it may have enough 10, 15, or20 micron particles in it that you can not see to cause a real problem.

If you are going to keep this coach, I would spend a few dollars and at least install a manual priming pump if there is not one in the system.

Gerald

[Dave Atherton]

Gerald, thank you. Reading in between the lines with John set up,it sounds like
His motorhome is setup with the Racor FR -60 filter system ( he mentioned last on
his post hearing a electric motor noise ) an that could be the motor in housing.
Depending on condition of the Racor setup he may have additional problems, if this is
correct the secondary fuel filter is in the open and has the plate to remove for the hand pump.
The bleed plug is also right in the open on filter base. Dave

[john brunson]

Pictures when I get back to the barn!

[john brunson]

Could it be that this is the original Catipillar filter head without the primer pump?? If so, where is the bleeder screw that allows air to escape?

[Dave Atherton]

John, looking at picture on left that is your secondary fuel filter and by removing plate on fuel filter
base you can install a hand primer pump like Gerald suggested. One thing I do see that you have a 10 micron fuel filter for your secondary fuel filter but would recommend using the Cat 1R- 0751
2 micron fuel filter. ( will prevent lot so cost ahead with your engine. ) Note: the Cat 3126 A, of
which you have has a very tight filter system that calls for the 2 micron filter with your engine
and all Cat Electronic engines made. Dave Atherton Retired Cat Mechanic

[john brunson]

Dave,

OEM Cat 1R- 0751 filters are on order.... can you provide part number for prime pump and gasket?? Also, how much clearance will be needed to extend the plunger??  Last question sir~ If i install this prime pump, where within the fuel system will the air exit as I pump?  I have observed a small knob/ valve on others that open to facilitate exhaust of air from the fuel system.  Is the primer pump only half of what is needed?

[Dave Atherton]

John, information on Cat 3126 A  engine S/N 1WN Remote fuel filter fuel Priming pump.
Fuel priming pump ( hand ) Part number 105-2508, Gasket for fuel priming pump part
number 1P -0436. There should be room but being this is a remote location can be moved
with no problem. Note: with the Hand fuel priming pump the way it works, top Knob has a
lock for pump plunger in the down position turn C.W. untill tight. To prime fuel filter turn top
Knob of plunger C.C.W and pull outward and pump slow in & out ( has two poppet check valves
size of a dime in base of hand prime pump, that works same as a bilge pump on a boat. )
Leave fuel filter a little loose on filter base to let air escape, when fuel comes out tighten fuel filter.
Than push plunger down to bottom ant turn C.W. untill tight. This will prevent any air entering the
fuel system or fuel out plunger. Last thing age of your engine there is no vent plug on fuel
fuel filter base that is why leaving fuel filter a little loose to let air out untill diesel fuel is
present than again tighten. Dave Atherton Retired Cat Mechanic

[Grant Ralston]

Dave, I have never changed my fuel filter myself.  I have attached a photo of my setup.  I assume I will spin on the new 0751 dry & fresh out of the plastic wrap, leave the filter a little loose, than pump the bulb pump on the primary filter until I have diesel leaking from the secondary fuel filter.  There is a small vent screw next to the bulb pump on the primary filter that has always confused me, but based on your above response I will ignore this vent screw and just bleed the air from the loose secondary filter.  Am I correct?

Thanks!

[Dave Atherton]

Grant, thanks for pictures, makes things easy to understand. Let get started the filter
to your left is your primary fuel filter with hand push primer pump on top of fuel filter.
The Cat fuel filter on the right is your secondary fuel filter ( this is very important that
you buy a Cat 1R-0751 2 micron fuel filter and replace with the same Cat fuel filter ).
remove your secondary fuel filter wipe filter base off dirt on sealing surface, install new
secondary fuel filter and leave a little loose before filter base. ( leaving little loose will
let air escape when pumping fuel to fill filter. ) Go back to the left primary fuel filter,
this is your call on replacement or drain water from bottom of primary filter. Looking
at install date I would suggest replacing both primary and secondary fuel filters. After
pumping primary fuel filter with fill with hand pump on top of left filter than keep pumping
and the secondary fuel filter will fill and let air out being filter is loose. When fuel is present
tighten up secondary fuel filter, wipe off fuel on filter you are ready to go. The reason for
leaving secondary fuel loose and letting air escape, if not you are pushing fuel through the
fuel rail on head than the fuel regulator on rear of head before return excess fuel to fuel
tank in front.    Dave Atherton Retired Cat Mechanic

[Dave Atherton]

Gentleman, I have mentioned this before about aftermarket install of parts. Taking a close look at Grants pictures of fuel system, primary fuel on left and secondary filter on the right. Looking
close at fuel lines and fittings connecting fuel lines. What we have is use of hydraulic hose with
crimp JIC hydraulic fittings. Where the problem is located, the rubber center of the hydraulic is
starting to break down with age and the diesel fuels being used today. I have several pieces of hydraulic hose from motorhomes that have failed that I will pass around at my Diesel Seminars.
I do have a answer to the above problem that MH owners can repair and correct at home with
little outlay of money. The problem mainly located in the Cat 3126 A, B , E engines and units
With the Racor filter system with electric motor in housing. I would suggest looking real close
at this problem ( break down of inside of rubber center of fuel hose ) If in question I would change your fuel filters, and carry spare filters on board. We need to understand some of our motorhomes
have never changed a fuel line and some 20 years + old and life end has been reached in some
non-cat standards. Dave Atherton Retired Cat Mechanic

[john brunson]

primer pump on order....  so what about the hydraulic hose that is "Downstream" of the primary filter?? replace?

[Dave Atherton]

John we have a fuel supply line from fuel tank to primary fuel filter, than supply
line from primary fuel filter to fuel transfer pump. Where problem has surfaced
fuel supply line has a rubber center that is starting to separate and sending rubber
debris into fuel system ( in its day the use of hydraulic hose and fittings was the norm
for builder of motorhomes ). Now after 15 to 20 plus years have passed use of hydraulic
hose for fuel system, has out lived its life. MFG. have replaced hydraulic hose with
plastic hose for non pressure fuel lines ( suction fuel line from fuel tank to transfer pump )
Dave Atherton Retired Cat Mechanic