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If all the O Rings were missing as in put in without them, how much do you think the oil will rise on the dipstick in say 1000 miles.  I overhauled the engine and was not there the day my helper put the pumps in. They were all there in a box cleaned up minus O Rings. He said he installed them. After 1000 miles I picked up 1/16" of oil on the dipstick. I figure with the square inches of the oil pan a 1/16  has to be at least a quart. OPINIONS PLEASE

Thanks Oh E7 460 2000 yr.

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If he installed all EUP's without o-rings the engine would not start and would be full of fuel in no time. Plus, fuel would be running all over the right side of the block. I don't think I would be worrying about a 1/16" of an inch since so many things could affect oil level. Now 1/4" + in 1,000 miles--- maybe then I'd worry. 

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Do an oil sample and test fuel content. If you have fuel, viscosity drop,  pull EUPs and install the special application triangle cut ring. Mack had some seepage issues so they made a seal kit to help remedy light leaks at EUP bores. 

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If it was me I would start with asking your helper if he install the o/rings.

  • Thanks 1

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I don’t think he can have no rings installed.

My wild guess is 4-5 minutes, full RPM, without any o-rings, would fill the crankcase to fill tube inlet, if engine would even run with that amount of pressure drop. 

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34 minutes ago, Mack Technician said:

I don’t think he can have no rings installed.

My wild guess is 4-5 minutes, full RPM, without any o-rings, would fill the crankcase to fill tube inlet, if engine would even run with that amount of pressure drop. 

Mack Tech is correct in my opinion ! how ever  It is possible he could have nicked an oring but with even one missing I believe the engine would be fuel of fuel in short order if it would run at all .

This also may be unrelated to the oring job ,the fuel transfer pump seals can leak past the shaft ( its not uncommon !)

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Thanks Guys Im due for an oil change soon. I will check more after that. Thanks again im relieved.

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i agree that i don't think it would even run with the o rings missing. 

 

i would mark a place on the ground to check the oil. drive it a while and park it in the EXACT spot. wait the same amount of time after shutting off the engine to check as well. but very slight grade differences can move the level on the dipstick 1/16th of a inch very easily. i used to drive myself nuts with that kind of stuff when i first bought my first truck. 

 

pull a oil sample and send it in for analysis. that will tell you conclusively if there is any fuel contamination. cat sos or Blackstone labs. 

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Sent one out on Mon.  Thanks  Maybe on a fresh rebuild some fuel is getting past the rings.?

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I got analysis back it was less than 0.50 % on fuel. So i guess i was worried about nothing.

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I changed the oil and ran it. Checked the next day, it was right at mark on dipstick.  6 weeks later its 5/16" above mark. Seems to be gaining 1/16 a week, which is about 1200 miles.   Any  ideas.?  Maybe getting past the rings.? Has about 10,000 on overhaul.

Thanks for any help.

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Thanks.  I replaced the the transfer pump yesterday and checked it with air pressure and seal wasnt leaking. I guess the eup seals is all thats left.  Thanks

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Three spots...

1. EUP rings

2.fuel pump

3.fuel gallery plug

Your block is drilled end-to-end to create the two fuel galleries for you EUPs. If you look at the front of the block you will see one drilling plug, the other lower plug is under the timing cover. If it leaked you would take on fuel internally. Not a popular leak though. 

Always a little fascinated the stems on an EUP hold fuel back. If you ever dump an EUP pull the spring off and pump stem out of your core. No seals. The fuel plunger has thousands of psi of fuel on one side and crankcas on the other side. Metal sealing through fuel film only. I don’t view them as able to stop 100% fuel x-over, but generally they do. 

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Just happened to lose an EUP in one of the 934D engines yesterday...…..

EUP.thumb.JPG.f6f1c4f9069911a6436076967394a5ec.JPGEUP1.thumb.JPG.491fe2f2a7a70ae055cc5018782df0c1.JPG

 

The Gold surface is your seal between the fuel column being injected and your crankcase. I don't see it as a 100% efficient seal and would allow a minimal acceptable fuel x-over with age and wear.

Edited by Mack Technician

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Is there a fix for this, other than replacing the eup.?

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Did you go through the service bulletin I made reference to? Mack doesn’t suggest changing EUPs for the issue. 

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no i didnt. could you post it again.?  Thanks

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you mean SB-221-038.?  I thought that was about the Delta seal kit.?

I read it again and it said nothing about not changing EUPS. It was just about the DELTA seals and installation

I was referring to your post about the shaft being worn on the  EUP.?  Is there a fix for that.?

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No fix, I've never seen an EUP changed for contaminating the volume of oil via plunger leakage as illustrated. It's not a perfect seal, but sufficient. I think a trace amount could potentially come from a steel-steel seal like the injection plunger uses. 0.05% as you listed...…?……...maybe, but that does not qualify a contaminated engine? 

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OK Thanks. I just sent a sample to Blackstone yesterday. Hopefully it will be ok.  Dont know why its gaining oil.? A fresh rebuild should be using some.

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