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General Boards => Technical Support => Topic started by: john brunson on November 16, 2015, 08:59:58 PM

Title: Cat 3126 short list of inspection items.
Post by: john brunson on November 16, 2015, 08:59:58 PM
OK so I have logged about 300 miles on this new to me engine...

Does someone have a "Short List" of stuff that I should be looking for?  Stupid stuff that may rise up to bite me on the behind if left unattended? It seems to run really well with temps and oil pressure exactly where the operators manual indicate.

I have greased the chassis, adjusted the parking brake, serviced the jacks, cleaned the refrigerator burner, serviced the furnace, aired the tires, checked fluids, serviced batteries, fixed my baggage door fiasco, and replaced all the halogen puck lights with LED.  The oil was changed obviously just before purchase and I am about to try to inspect the engine galley contents for impending problems...

What about it guys??? what should I be looking for??  I am planning a trip to the coast on Friday.

//John
Title: Re: Cat 3126 short list of inspection items.
Post by: Marty and Suzie Schenck on November 16, 2015, 10:29:43 PM
When we purchased our 1998 Monterey it came with a bulletin from Cat. The bulletin explained that the Cat computer and the Allison computer do not communicate with each other, they work independently. Meaning that when you are climbing a grade or hill, the Allison does not know if the engine temp is rising (if it is) so to downshift to keep engine RPM's up. The bulletin stated: if engine temps start to rise on a grade, the driver needs to manually downshift the Allison to keep RPM's at or around 2300rpm to move more air through the radiator. Also, keep that radiator clean. Hope that helps. Marty
Title: Re: Cat 3126 short list of inspection items.
Post by: Steve Huber on November 16, 2015, 10:33:51 PM
John,
2 items related to cooling;
-Be sure to lube the fan shaft when changing the oil. There is a lube port on the fan shaft. Access is from the passenger compartment.
-Wash out radiator at least annually or after each long trip. use a garden hoe; not a pressure washer. Wet it  down and spray it with a mixture of water and Dawn dish soap. Let set a few minutes and rinse. I did mine from both sides.
Happy travels,
Steve
Title: Re: Cat 3126 short list of inspection items.
Post by: Edward Buker on November 16, 2015, 10:37:07 PM
John,

Transmission oil.... Transynd or not and when changed, transmission filters...when changed, front wheel hubs...oil level and when changed last, if greased bearings in front end .....when last repacked, antifreeze.. what type and if it has a conditioner cartridge, what is PH, how old is it? Belts....adjusted properly and how old? Differential....what is the level and how old is the oil. Air cleaner...how old and is it a high quality filter? Fuel Filters...should use Cat advanced for final filter, how old are they, consider replacing?

Inspect hoses for chafing and tie wrap away from hazard or clad with larger hose slit and used as covering for any hazards. Examine any leaks to see if they are of concern. Lube and clean latches, gas shocks on doors may need replacing...just a starting point. Sealing for leaks on the roof, cracking lap sealant inspection.

Later Ed
Title: Re: Cat 3126 short list of inspection items.
Post by: john brunson on November 17, 2015, 01:35:22 AM
Wow... Raising the bed really gains you very little... Exposes a rat's nest of wiring, a few more relays, solenoids, the transmission, and about 60% of the rocker arm and injector cover.

Transmission fluid level is good - no clue whether it is synthetic or dextrin III.

I appear to have two belts a large serpentine and a smaller one.... Serpentine has no cracking or evidence of wear.... If this were my truck, I would say the tension was good.  Smaller belt looks good but no clue what it drives.

I am slowly beginning to identify systems, I get a much better view of the accessory chain from the underside- lots of hoses look to be the silicone variant (blue) and supposedly last longer... No clue if the cooling system has a conditioner/ filter.  Obviously, there is an integrated intercooler within the radiator.

I ran the engine pretty hard coming home from Florida and temps stayed reasonable.. Radiator looks clean but will definitely flush it with a solvent that will dissolve grease but not aluminum.

I have an oil leak on the side opposite the exhaust manifold and turbo... Not valve cover but possibly one of the access covers there.... Need to try to snug the covers a bit.

Question, is the fan shaft serviced with a grease zerk?i saw no way to lubricate at all.... 

Question, is there any documentation on the hydraulic system? It appears to boost brakes and steering.



Looks like it has been three years and 8 thousand miles since major service- except oil...it  Looks new

Wish me luck....and chime in with answers if you have any.
This thing has me a little intimidated right now.

Title: Re: Cat 3126 short list of inspection items.
Post by: Dave Atherton on November 17, 2015, 03:03:51 AM
John, little insite on your Cat 3126, oil pressure at rated speed with SAE 10W30 or with
SAE 15W40 is  (35 to 70 psi). low oil pressure is normal at idle and gauge read changes.
The diagnostic lamp will come on if oil pressure drops below 5 psi. Engine Oil Temperature
that is higher than normal indicates a heat problem in the lubrication system and or cooling
system. Water Jacket Temperature range ( 190 to 215 F ), the maximum allowable temperature
with the pressurized cooling system ( 220 F ). Water temperature readings will vary with
applied load. Fuel pressure ( system pressure 61 to 65 psi ), gauge indicates fuel pressure
to electronic unit injectors from fuel filter. Indicator should read normal range on gauge, decrease
in fuel pressure will indicate a plugged fuel filter in most cases. Use only Cat 1R-0751 fuel
filter and your secondary ( fuel filter mounted on the engine.)

Emergency Engine Features:  Engine Oil Temperature Sensor ( operating temperature range
-40 to 258 F ).  Inlet Air Temperature Sensor ( operating range -40 to 258 F ),
Diagnostic Flash Codes: Coolant level Sensor Circuit Fault  (12), Oil Pressure Sensor  Fault (24),
Inlet Air Pressure Sensor Circuit Fault ( 25), Coolant Temperature Sensor Fault (27) Inlet Air
Temperature Sensor Fault (38), High Coolant Temperature Warning (61), LOw Coolant Level
Warning (62 ), Very High Intake Manifold Air Temperature Warning (64), Ignition Key Switch
Circuit Fault (71).  There are more Diagnostic Codes but these are the most important ones.
these codes can be bought about via your key switch turning on and off. Word of caution with
a Cat HEUI injection system would suggest changing oil at correct service or before. this Heui
system does not like entended service overdue. Dave Atherton Retired Cat Mechanic
Title: Re: Cat 3126 short list of inspection items.
Post by: Steve Huber on November 17, 2015, 05:38:47 AM
John,
Small belt runs the water pump. Think the fan shaft lube point is an oil "cup", not a grease zerk.
Steve
Title: Re: Cat 3126 short list of inspection items.
Post by: Jerry Emert on November 17, 2015, 08:01:09 PM
John,
Small belt runs the water pump. Think the fan shaft lube point is an oil "cup", not a grease zerk.
Steve
Steve, non mechanic here as you know.  I know what a zirk fitting is, what is an oil cup?  I'm in the middle of trying to figure out how to make a schedule for my yearly maint. coming up in Feb/March.  Thanks
Jerry
Title: Re: Cat 3126 short list of inspection items.
Post by: David T. Richelderfer on November 17, 2015, 08:48:36 PM
https://www.google.com/search?q=oil+cup+lubricators&biw=1920&bih=878&site=webhp&tbm=isch&tbo=u&source=univ&sa=X&ved=0CFMQsARqFQoTCNTT5o-qmMkCFYHnJgod-qIKlw

An oil cup usually sits over a bearing.  There will be a small or large oil storage "cup," depending upon the size of the bearing and the bearing's lubrication requirements, with a straw-like stem going from the bottom of the cup's oil supply down into the bearing housing.  Many oil cups are glass so that a quick visual inspection tells the maintenance technician if the cup is low on oil.
Title: Re: Cat 3126 short list of inspection items.
Post by: john brunson on November 17, 2015, 09:14:18 PM
No zerk or oil cup that i can see on the Fan shaft.... Dave Althern can you suggest a device to interrogate the Powertrain control module for codes and operating parameters?  I own OBDII equipment but nothing for a diesel.

gonna peek agin this afternoon before the rain begins to fall.... mabye take pictures

oh yea... is there a special 90 weight called for in this moose of a differential? or will any 90 weight gear oil with an EP agent work?
Title: Re: Cat 3126 short list of inspection items.
Post by: Steve Huber on November 17, 2015, 09:19:57 PM
John,
I was mistaken. Called my maint guy to double check. It is a grease zerk. To access on Contessa, you had to put slide out and crawl to front of engine to access fan shaft. had to use hand grease gun to apply grease. This was on a 3126B but would think 3126 had same fitting.
Steve
Title: Re: Cat 3126 short list of inspection items.
Post by: Dave Atherton on November 17, 2015, 09:42:53 PM
John, the small pulley had been updated and has a sealed bearings  in hub (2.) You were asking
about OB2 connect to allison ( problem the connector looks like a OB2 connector but will not
work because it has a Packard Diagnostic Connector. We are steping back in time as far as
connection to allison I do have a packard diagnostic connector along with allison solfware but
I'm located in Quartzsite ,Az . OB2 in most cases will not work on engine or transmission. Question
about Lube oil in rear axle third member that is 90 weight. You want to add or drain and change
oil. One thing to remember the third member is not a problem area ( just make sure the vent
on the axle is allways open and not plugged and not over filled Recomment one inch below fill
plug. Back to vent on axle housing is plugged and air cannot vent to outside, axle housing will
pressure in housing and depends will push out Pinion seal that driveline connects or wheel seal
which will need to replace seals. Again make sure axle housing vent is not plugged.
Dave Atherton Retired Cat Mechanic
Title: Re: Cat 3126 short list of inspection items.
Post by: john brunson on November 17, 2015, 10:39:47 PM
Just crawled out... No sign of a grease zerk on the fan shaft.... Will look for another way to get to accessory chain... Got to be a better way...

Front wheels are oil bath.... Rear axle bearings appear to get lube from differential?

OBDII is strictly automotive and light truck as far as I know... This is different see picture

Title: Re: Cat 3126 short list of inspection items.
Post by: john brunson on November 17, 2015, 11:17:26 PM
Ok remember Dave this is a 1995 model engine... I found a picture of the zerk online (I think) looks like 12 o'clock right behind the pulley... Safe to assume I have a sealed bearing if no zerk is there?

http://www.irv2.com/forums/misc.php?postid=1108515&threadid=113411&external_page=http%3A%2F%2Ffarm7.staticflickr.com%2F6201%2F6141290921_4fccaa9a4d_z.jpg

Thinking of sawing me another hole in the closet floor... Anyone done that before?


Title: Re: Cat 3126 short list of inspection items.
Post by: Dave Atherton on November 18, 2015, 12:33:31 AM
John, more than likely pulley has been changed out with sealed bearings but there has been grease zerk on pulley when sold. Looking at picture of Data connector it is J-1708 6 pin connector that
is used for 3126 electronic engine diagnostic and on earlier units like you have same J-1708 is
also used for allison transmission diagnostic. Back in that time frame some MFG. used a connection
for diagnostic for allison called a packard connector that some what looks like a OB2 connector.
Picture is worth thousand words on 6 pin connector. Dave Atherton Retired Cat Mechanic
Title: Re: Cat 3126 short list of inspection items.
Post by: john brunson on November 18, 2015, 12:43:14 AM
So if they installed a sealed bearing, the zerk won't take grease right?
Title: Re: Cat 3126 short list of inspection items.
Post by: Dave Atherton on November 18, 2015, 01:36:27 AM
John, if you did find a grease zerk than fan hub will take grease. If you look fan hub
over real good and cannot fine where a grease zerk has ever been than the fan hub
has sealed bearings. Reason Cat updated fan hub because of over greasing and pushing
out grease seals. Dave Atherton Retired Cat Mechanic