Readying for the KW

[bccat]

Quality control on that pimp for sure.

Jpaydirt on YouTube had problems with his n14 oil pressure, his reman oil pump was one of his problems

 

[Truck Shop]

Jpaydirt on YouTube had problems with his n14 oil pressure, his reman oil pump was one of his problems

We lost a 525 N14 in 2006 due to oil pump failure, original pump had 250K on it. It's gotten to the point of
a person could have more trust in one from a junkyard.

 

[Mobiltech]

It is normal for them to spin fairly easy unlike a hydraulic gear pump that would need a wrench on to turn but that seems way too easy!
Pull the back cover off and look inside.
I always try and keep my core returns until the engine is up and running good .

 

[56wrench]

Also, i always like to check the oil pump relief valve on any pumps that have them, even on new/reman pumps even if its only to make sure there is no crap in the seat/spool. I would hate to be the one in a thousand guy who gets stuck with one that doesn't operate correctly. I know you shouldn't have to but s!!t happens

 

[DMiller]

Spoke to Cat shop and parts
Shop said should rotate by hand but have enough resistance to not continue to roll

Parts said warranty is a year so not a problem to swap.
Will have pump tomorrow afternoon, i am off .

 

[kshansen]

Spoke to Cat shop and parts
Shop said should rotate by hand but have enough resistance to not continue to roll

Parts said warranty is a year so not a problem to swap.
Will have pump tomorrow afternoon, i am off .

I think I would open the box the "new" one is in right at the parts counter and see how it turns compared to the one you have now. Call me a worry wart but I would be afraid that the same guy who assembled the last one did the next one you get.

And if you are on good terms with the dealer I would ask if there was a chance they could open up the one you are having the low pressure problem with while you watch. Sure would be nice to know there is a problem in it!

 

[JPV]

We had a 465 horse N-14 that would lose oil pressure after it warmed up. I cleaned and shimmed the relief valve with no results. The gear inside the pump was pressed on the shaft with no key. When it warmed up it apparently expanded a bit and would slip on the shaft. I pulled the pickup tube off the pump and stuck a big screwdriver in there to pry on the gear to see if it would turn to figure that one out. Fortunately there was no damage to the engine.

 

[Truck Shop]

was pressed on the shaft with no key

Those are actually heated and shrunk/cooled to shaft.

 

[DMiller]

Sweat fit usually locks tight
Must have been off sized just enough on the N14

 

[DMiller]

Old HS friend of mine I did not realize is the CAT Svc MGR at CoMO, he email sent me the diagnostics procedure pages for Low Oil pressure against engine codes which I have not checked, after looking at the notes from Mac I have been speaking to his first thought was worn pump suction throat and the ability of the O-ring to lose seal, a Chance in a Lifetime event HE encountered in 2010. Made me go Hmmm!!! His suggestion and I explained I already had it ordered was to replace suction tube AND Pump as housing is likely worn JUST ENOUGH to allow that event to occur, is not a check by Reman Techs as to that throat dimension just a visual for O-ring/tube head erosion, a MAYBE?????

 

[Nige]

His suggestion and I explained I already had it ordered was to replace suction tube AND Pump as housing is likely worn JUST ENOUGH to allow that event to occur, is not a check by Reman Techs as to that throat dimension just a visual for O-ring/tube head erosion, a MAYBE?????

Right now anything is a possibility IMHO. You're way outside the "normal" stuff now.

 

[DMiller]

Have essentially checked or replaced all the ‘normal’ stuff, are well out of ‘the box’!!

edit
Am so far out of the box to be in the warehouse next door!

 

[Truck Shop]

This issue right here is where a shop would lose there ass on a job like this. Theses issues are easy to miss because who in the hell
would look for it on something as simple as a oil pump. Way out of norm.

 

[Willie B]

Have essentially checked or replaced all the ‘normal’ stuff, are well out of ‘the box’!!

edit
Am so far out of the box to be in the warehouse next door!

Is there a way to narrow it down? Close the outlet on the pump, & see if it makes pressure?
4 reasons an oil pump won't build pressure:
It isn't rotating.
It isn't priming. Air doesn't pump really well.
Pump doesn't pump.
Not enough restriction in all the combined passages to build pressure.

I'm not there, I'm only half a mechanic, but I think it'd be helpful to narrow it down to what is causing the failure.
It occurs to me that engine design wants oil to flow, passages are sized to provide flow everywhere. Open one path too big, (as in a bad bearing) you lose pressure everywhere. While volume of an oil pump is reduced if pumping only air, the ability to build pressure is also reduced. Air flows easier than oil.

Is there a way to tap the system on the pressure side of the pump & send oil in by other pressure source.
Again, outside the box here, I might try a retired propane cylinder, a nipple & T. Through the T, install a dip tube plumbed to the oil pressure sensor tapping, or what have you on your engine. Tap in the T gets a Schrader valve to pressurize the propane tank. Funnel the tank full of oil. Feed it through the engine.
It'll give you some information whether your engine is wasting flow, or if pump isn't providing flow. It'll also flood every bearing surface with oil it likely wants about now.

By the way, I have a few of these rigs to put gear oil into transmissions, differentials, etc. They work for oil undercoating (rustproofing), solvent washing, etc.

 

[DMiller]

Pretty simple pumps, USUALLY either pump or do not, in the case with this type they use O-rings to seal the joining surfaces of Suction and Discharge pipes to the pump housing not Bolted Flange or permanent Gallery interfaced direct to pump housing. Does eliminate the chance of a blown gasket or loosening bolts somewhat but allows other points of fault. In this case a 1 1/2" Tube drawing thru a pinholed tin sheet screen not mesh so ANY inleakage point becomes a Monstrous air entrainment issue. The lack of a Tight Solid Seal allows that hard suction pump to draw more air than viscous oil. Will definitely know when these parts are back on.

 

[DMiller]

Pump warranted, they opened and checked
Had .025 drive impeller end clearance to housing driven had .040.
Had .035+ clearance impellers to housing. Questions ticket going with pump to Peoria.

next up noted orange orings on tubes
CAT parts man supplied at Other shop of theirs incorrect for app correct are black and harder,
larger circumference
Techs in shop made notes!!!

I was set up for success

 

[kshansen]

My question now would be: "Did they make the same measurements on the pump thy gave you to replace this one?" Hate to be negative about things, but if someone sold me a quart can of oil and I found it only had 28 oz in it I sure would not assume the next one out of the same carton was going to have 32 oz with out measuring it!

 

[kshansen]

Just for fun tried finding spec's on oil pump on SIS. could not find anything on the gear clearances right off, see below:

But going by the width of gears and the depth of bore in housing and using the max for depth of bore and minimum for width or the gears my math says the max end clearance for the gears should be 0.0068! So if I'm reading your post right one gear had 0.025 and 0.040! So my math puts the "good" gear at 0.018 over spec. and the "bad" gear at 0.0332 over spec.!

Not an expert on gear pumps but seem to recall that gear pumps are pretty fussy about end clearances at least the hydraulic pump I had to deal with were!

 

[Truck Shop]

Those pumps can take a beating, I had one years ago on a b that had run something through
it. gears and bores were real sad-and it still pumped in spec before rebuild.

 

[DMiller]

This one was beaten, and yet still making some oil pressure. Should have it back together this Saturday & have an idea if managed to cure this. IF Good Oil pressure then allow to warm, re-run overhead, then set covers and eventually perhaps Sunday re-set the Hood. Then on to the remaining work, bags and lines shocks brakes electrical and lighting, look all over repair anything that needs to be covered. Start aligning parts list to order exhaust for after paint.

Then the search for Rubber sometime around Xmas or towards my Birthday in Feb, may even get it inspected and licensed come spring.