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D5C fuel filter in fuel tank question

R

rockbottom

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Jun 8, 2015
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Location
mississippi
I have a D5C and it is starving for fuel. I changed the filter, same probem.
I took the line loose from the petcock to the tank and very little fuel leaks out. I took a hose, put it over the fitting and blew through it, I can hear the fuel buble and now the line is passing a good volume of fuel.
Question, is there a filter inside the fuel tank? It appears there is debris in the tank. what is the best way to pull the tank and clean it or is there a better way to deal with this problem.
 
kshansen

kshansen

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nowing75 said:
What's your s/n. Can send you some info
Click to expand...

S/N is always one of the most important things to include as seems to like to build many different versions of what on the face of it from just the model number looks like the same thing. Also what some don't know is the hydraulic system on dozer will not be shown in the parts book for the tractor section and the same for the dozer, dozer is the blade and arms, tractor is the tractor. It can get confusing if like myself you only occasionally work on what most will call a Bulldozer!

Of all the Cats I have worked on in the last 45 years do not recall any with filters in the tank. Most of the older machine have a screen type strainer somewhere in the system before the fuel lift pump.
 
R

rockbottom

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Location
mississippi
SN 6ZL00Z59. mine has a sediment filter out of the tank then a cartridge typr fuel filter in the engine compartmemt before the injector pump. I had a similar problem on a ford 3000 tractor and found it had a small filter inside the tank.I am wondering how to fix the fuel delivery problem. thanks for the reply
 
Nige

Nige

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There is no filter or screen in the tank. It's most likely full of sediment and/or water that will have accumulated over time. According to the Service Manual the tank should be drained of water every week. Yours might now be so contaminated that it will require removal and a thorough internal cleaning with a hot water pressure cleaner.
 
C

caterpillarmech

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Nov 7, 2011
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533
Location
Florence Texas
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Field Service Supervisor
The C has an ecology drain under the bottom of the tank. It is located directly over your final drive. Nige is correct, no filter. It is just an open tube. I have had to pull several tanks to clean them and it is no fun. Drain the tank and filter the fuel if you can. Then look at the bottom of your tank. Likely you have a layer of water and sludge on the bottom. This is what needs to be drained off weekly. The ecology drain has a 1/2" square drive plug in it. You remove the plug first and then have to open the spring valve. You can hold it open with a fitting 16 o ring boss/16 jic should be the size. Be careful as some of the valves liked to stick open.
 
R

rockbottom

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Messages
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Location
mississippi
not sure what a16jic is? sounds like if I can get the D5 on a slope with the drain down I can try to flush the tank from the filler opening and hope for the best. I agree pulling the tank does not look like fun. thanks for the feedback
 
Nige

Nige

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You'll probably expend a large amount of effort trying to clean it and still not be satisfied with the results. Bite the bullet and pull the tank off would be my call, unless there is a manhole in it somewhere that you can remove.
 
K

Kemo

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Nashville, TN
I am a newbe and realize this is an old post. So Caterpillar makes a pipe nipple , a 7b 7908 pipe nipple to be exact. I have never seen one on the internet and the maintenance manual recommends using this device after taking the ecology drain cap off. How does this work for draining the tank? I have about an inch of sludge/rust in the bottom of this tank.
 
Nige

Nige

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There is a spring-loaded check valve inside the ecology drain assembly. Screwing the pipe nipple into the ecology drain from the bottom pushes the check valve upwards and opens it to drain. 7B-7908 is actually a 4"-long piece of 1" pipe with NPT threads on both ends.
 
K

Kemo

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Nige, thanks for the insight. So I could probably pick one of those up at a hardware store instead of paying $20 for a designated pipe nipple ?
 
D

Delmer

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Not knowing anything about the "ecology drain", I would guess a pipe nipple would work fine. If it's 1" npt, the hole will be 1 5/16" or so. I'd guess that was the design in order to hook up a hose to reduce spillage in tight locations.

If you have an inch of sediment, I'd want as large, short and straight a hose as possible, and set up a pump to flush the rust out. Or, use buckets and a siphon, set one bucket of diesel on top of the ROPS, siphon it into the tank moving the hose to rinse sediment to the open drain going to another bucket. Let that bucket settle, then siphon the fuel off and rinse again until you don't get anymore sediment. Or, pressure wash with water. Or take the tank off and clean it by rotating with gravel.
 
Nige

Nige

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Kemo said:
So I could probably pick one of those up at a hardware store instead of paying $20 for a designated pipe nipple ?
Click to expand...
Correct.

As mentioned above, I fail to understand why the designers put an ecology drain on a fuel tank when you want to drain water and sediment from it on a regular basis.

Also based on what you indicated the tank really needs to come off to get cleaned, not just the water drained.
 
K

Kemo

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Thanks Nige, I am pressure cleaning the tank, not just draining the water. It took about 55 gallons of water to purge the junk out. Replacing the fuel sender only after tank is completely dry by using forced air. The new sender is about 1/4 mark off from the fuel gauge. Is that gauge calibratable ? Thanks for your valuable insight!​
 
K

Kemo

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I did order the sender from CAT. I will check out the gauge and post results later. The 7b 7908 nipple pipe was ordered from CAT also. The difference I found between the CAT nipple and a store bought pipe nipple is that the CAT is beveled slightly on the inside in order to seat correctly to the drain cock plunger that the pipe pushes up when screwed in. A store pipe nipple may work but I didn't want to chance damaging the drain cock. Once the tank was cleaned, I removed the ecology drain assembly. It was deteriorated and the spring had to be replaced but now it works as designed. If maintenance is done on this equipment as described in the manual, these problems would not exist. Drain the trash weekly, keep the tank full. How hard is that? Thanks for your insight!!
 
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