Community Forums

Cat · 04-03-2020, 11:55 AM

Quote:

Originally Posted by wclogger1

Rather than removing the hose is it possible to just put a test fitting in to the same gallery?
I have a C7 and according to our Cat dealer there is a spare gallery plug in the same area as the hose,tube with 7/16 - 20 ORB threads plug.

Any of the plugs along the side of the head along the same level as plug 7 should get you actuation pressure. Be aware this pressure can be 3900 psi or higher if the pump is malfunctioning. Normal pressures will be 0-3400psi depending on engine operating conditions. Be Safe, Safe Travels

discovery39s · 04-04-2020, 07:31 AM

Quote:

Originally Posted by Cat

Any of the plugs along the side of the head along the same level as plug 7 should get you actuation pressure. Be aware this pressure can be 3900 psi or higher if the pump is malfunctioning. Normal pressures will be 0-3400psi depending on engine operating conditions. Be Safe, Safe Travels

Hence the term: "Common oil Rail". all the ports are common as Cat indicated.
The highest I have ever seen is 4,600. That was due to a defective control valve in the HEUI. Removed, cleaned, reinstalled and all was good.

Use a 5,000 psi rated gauge and you should be safe. I highly recommend installing a snubber before the gauge or the axial pistons/pulsation will beat the gauge to death. They offer snubbers designed for oil, be sure it is or you may get erroneous readings. Any good hydraulic supply shop would have them.

Stay safe

rabdnomaidx · 08-14-2020, 08:34 AM

It has been repaired after nearly a year!I had to haul it to a different repair shop and when the HEUI pump was changed, the rod on the lift pump was snapped off and it would run only when the primer was being pushed. He also found out that the head had a hairline crack in it and replaced the inner cooler and turbo. Thanks for all who helped out here. The APR valve was changed before we changed the HEUI pump, so we are hoping that all is well now for awhile! Thanks Again!

Quote:

Originally Posted by discovery39s

Agreed Cat. Also, If the drive nut is loose on the HEUI it can also cause loss of both oil and fuel pressure. I had this one challenge my brain until I checked the nut, it was loose.

I

Cat · 08-14-2020, 11:17 PM

Thats Great news!!!! Sorry to hear it took so much time and Money. There were a few incidents where the cyl head cracked. It wasn't a very common problem. But thank very much for reporting what the "Fix" was. Enjoy Safe Travels

charldk · 08-23-2020, 04:28 PM

Quote:

Originally Posted by rabdnomaidx

I have a 1999 Newmar Dutchstar with a 3126 that fires right up, but dies again right away.
The codes told me to change the pressure sensor at the pump, so I did and changed the ignition switch. Nothing changed. before this issue began, it started and ran kinda rough for up to 15 minutes and died. Oil pressure is good and registers while cranking. I had the starter checked and re-installed it as it tested good. The engine protect light is on also when it fires up, but it wasn't on when it was running rough earlier? It has a new fuel filter and primer. I am stumped and am about ready to have it towed to the shop. Tow bill is $1500.00 and labor is $170.00 per hour, so I am wondering if I missed something simple.
Any other ideas I could try first?

Desperate
TIA

Check the check valve coming out of the back of the cylinder head. Is it plugged?

rabdnomaidx · 12-02-2020, 07:24 PM

It looks like I am going to have to replace the short block and I have found one and the seller says it should work. I am double checking to see if what I know so far is accurate.
I have a 1999 Newmar Dutch Star with a 3126 7.2L cat in it the serial number is #7AS61902. the re-man block is a Reman C7 3126 -- OR-8943.
The seller says that they THINK it will work.
I just want to be sure that this block will work before I order it!
The OR-8943 number that is on the re-man block, I do not understand if it it is revelant to this situation or not! If so where do I look on my old block to find this number?
I have replaced all the sensors - the turbo - inner cooler - the HUEI pump - the ECM was checked and found to be good - replaced the head and when the head was removed they found one cylinder is bad! At this point, I would rather go with a re-man short block, rather than spend more on this old block. But I certainly do not want to purchase the wrong block.
HELP!

Cat · 12-02-2020, 10:06 PM

Quote:

Originally Posted by rabdnomaidx

It looks like I am going to have to replace the short block and I have found one and the seller says it should work. I am double checking to see if what I know so far is accurate.
I have a 1999 Newmar Dutch Star with a 3126 7.2L cat in it the serial number is #7AS61902. the re-man block is a Reman C7 3126 -- OR-8943.
The seller says that they THINK it will work.
I just want to be sure that this block will work before I order it!
The OR-8943 number that is on the re-man block, I do not understand if it it is revelant to this situation or not! If so where do I look on my old block to find this number?
I have replaced all the sensors - the turbo - inner cooler - the HUEI pump - the ECM was checked and found to be good - replaced the head and when the head was removed they found one cylinder is bad! At this point, I would rather go with a re-man short block, rather than spend more on this old block. But I certainly do not want to purchase the wrong block.
HELP!

You need to call Caterpillar give them your serial number and arrangement number if can find it. But they will have to have the serial number. They will tell you what the correct short block or long block number is correct. Call Caterpillar too much money not to call them. Keep us updated. Good Luck

rabdnomaidx · 12-03-2020, 01:00 PM

Can anyone tell me if there is a number on my 3126 Cat short block? I am trying to purchase a re-man short block and gave them my Engine Serial Number and they THINK it will work! Just want to be sure before I purchase a re-man short block.
TIA

Cat · 12-03-2020, 05:00 PM

Quote:

Originally Posted by rabdnomaidx

Can anyone tell me if there is a number on my 3126 Cat short block? I am trying to purchase a re-man short block and gave them my Engine Serial Number and they THINK it will work! Just want to be sure before I purchase a re-man short block.
TIA

Who are you talking to? If it is a Cat dealer they can get with Cat to confirm what OR is correct. If you're not talking to a Cat dealer Call Caterpillar. There is no number on your short block that will tell them which OR to use. Caterpillar parts exchange can tell you if you give them the serial number.