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D6 8U Injector Pump leaking

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3 years 5 months ago #227435 by LBrothers
Hi All,

The injector pump on the D6 8U is leaking a lot of fuel from somewhere on the engine block side... pretty hard to get anything in the back there to see what's going on.  
Looking for some advice before i try and remove the whole pump and also some advice on how to go about removing it.

Thanks
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3 years 5 months ago #227436 by trainzkid88
if you have the servicemans reference for the engine it should have all the relevant info.

is it a leak or a spray if its a spray then it could be from the pressure side of the pump. if its just a flow of fuel it may be from the low pressure side.
what is possible is the seals and gaskets have failed especially on a machine that was sitting for long periods.
have you got a inspection mirror or a borescope camera that you can feed down there to get a look.
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3 years 5 months ago #227441 by LBrothers
I don’t have a serviceman’s reference or borescope.

It’s just a steady flow.
It’s been about 5 years since it last ran.  
I cleaned it down and there doesn't appear to be anything coming from the high pressure lines going to the injectors.
if it's seals / gaskets I'm going to have to pull it out ?

Thanks

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3 years 5 months ago #227445 by neil
Replied by neil on topic D6 8U Injector Pump leaking
Check your bleeders are closed. They're on the backside of each of the injection pumps, six total. If all closed and not leaking, take front cover off the pump body and check for leakage into the interior. You can run the engine with that cover off to observe.

Cheers,
Neil

Pittsford, NY
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3 years 5 months ago #227461 by LBrothers
Thanks Neil,

I’ll try that out on Thursday next week when I’m back at the farm..

Can anyone tell me the easiest way to share videos on this forum?

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3 years 5 months ago #227462 by edb
Replied by edb on topic D6 8U Injector Pump leaking
Hi LB,
the scan below may assist you of where to look for the Bleeder Screws (if fitted) Neil mentions above.
Some later replacement pumps do not have these as Cat changed the fuel flow thru the main body to the pump unit by changing the ferrule from the fuel gallery to be of a self bleeding design.
Cheers,
Eddie B.
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3 years 5 months ago - 3 years 5 months ago #227463 by trainzkid88
check the the simple things first. usually they are the cheapest fixes. even a small piece of mirror would work just so you can get look at the area.
if it isn't the bleeders leaking or its leaking inside like neil suggests then yes its seals which is only due to age and the fuel of today being ultra low sulphur (the old seals dont like it) and yes to my knowledge it would have to be removed to be taken to an injection service unless of course you have the knowledge and equipment to rekit it yourself. get it wrong bad things can happen so i recommend getting it done professionally. not their should be engine oil in the bottom of pump case upto the level mark to lube the pump so undo that bung if it overflows then the pump may be leaking internally

the kits should be available from cat dealers or from mobs like florin tractor get a kit and take it with the pump. good idea to change the fuel filters too and there is 2 different types depending on serial number. we found that out with our 6u one type is spun wound cord looks like a reel of cotton and i cant remember the other type.
Last edit: 3 years 5 months ago by trainzkid88. Reason: clarity
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3 years 5 months ago #227674 by LBrothers
Hi All,

On closer inspection the fuel seems to be coming from between the body of the pump and the block that the bleeder screws are set in.
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3 years 5 months ago #227676 by Fat Dan
Replied by Fat Dan on topic D6 8U Injector Pump leaking

Thanks Neil,

I’ll try that out on Thursday next week when I’m back at the farm..

Can anyone tell me the easiest way to share videos on this forum?
 

The best way I found to shair videos is to use YuoTube and link to it.... There is most likily a better way ..... but I no know it?

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3 years 5 months ago #227682 by neil
Replied by neil on topic D6 8U Injector Pump leaking
There are o-rings underneath the pump body. Check if the retaining bolts are torqued properly. If not, torque them up and see if the leak stops. If not, you center the rack so the dots on the rack and the pump segments line up, then remove the retaining bolts on top of the pump body and lift and tilt to remove the plunger with the body. You then have easy access to replace the o-rings. You might as well do all six pumps - put them back in their original locations. Try not to remove the plungers from the bodies, but if you do, it's not a total disaster; just make sure that you flush the plunger and body well to remove even the smallest impurity, then put the plunger back in the same body it came from. They are matched. Cat has the new o-rings

Cheers,
Neil

Pittsford, NY

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