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Topic: 2002 U320 ISM Oil leak repair (Read 841 times) previous topic - next topic

2002 U320 ISM Oil leak repair

Please double check your part numbers before you begin

I had an oil leak at the rear of the motor and thought it was the valve cover gasket but after removal of the cover I found the orings on the injector harness was bad so I replaced both (2) of them
Cummins ISM For Sale | VanderHaags.com

Next was the front of the engine which I thought was the crank seal leaking. I decided that while I was their I would go ahead and replace all the seals on the front shafts Crank/Accessory/Alternator.

I removed the balancer by using a pry bar on the rear of it and using the lower motor mount and the bolts on the back of the face plate.. Tried the 3 prong remover but it failed.

Replaced the crankshaft seal with
Front Crank Seal Kit for Cummins L10 M11 ISM. PAI # 136117 Ref.# 4955665 4962745
Alternator Drive Seal Kit for Cummins L10 M11 & ISM. PAI # 136056 Ref. #...

Accessory seal with
Accessory Drive Seal Kit for a Cummins M11. PAI # 136081 Ref. # 3804304, 3803728
Accessory Drive Seal Kit for a Cummins M11. PAI # 136081 Ref. # 3804304,...
this one is best removed before you remove the belts to keep the engine from turning with the ratchet. I had already removed everything so I had to make a tool to keep everything from moving.

Next up is the Alternator seal
Alternator Drive Seal Kit for Cummins L10 M11 & ISM. PAI # 136056 Ref. # 3803894
Alternator Drive Seal Kit for Cummins L10 M11 & ISM. PAI # 136056 Ref. #...
Used a regular pulley puller on this one.. easy

Found that the alternator seal was the really bad one and the crank seal was behind that. I bought the crankshaft wear ring just inc case I needed it but I did not use it.. was really a tight fit on the crank seal..
Front Crankshaft Wear Ring for Cummins L10. PAI# 136043 Ref# 3820918 84854 99333
Front Crankshaft Wear Ring for Cummins L10. PAI# 136043 Ref# 3820918 84854...

Re: 2002 U320 ISM Oil leak repair

Reply #1 –
After cleaning everything and getting dirt off I replaced the new seals and reinstalled the pulleys and the balancer. Replaced the belts with new ones

Started it up and ran for a moment and I will take it for a spin this weekend to see how I did.. not to much work... took a few to figure out how to remove the stuff that was stuck but in the end it moved with either some wd40 or a breaker bar.

Re: 2002 U320 ISM Oil leak repair

Reply #2 –
I personally think your engine is way too clean and you should be asked to leave the forum.  🙂
Rick & Rhonda
2003 U320 4220  Build #6199
Was
91 36' GV 300 Caterpillar, 92 40' U280 300 Cummins, 97 36' U295 300 Cummins, 2002
U320 450 Cummins
(Guess we're hooked)

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Re: 2002 U320 ISM Oil leak repair

Reply #3 –
Nice write up David!
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: 2002 U320 ISM Oil leak repair

Reply #4 –
Nice job with photos!  Awesome!
Joe & Dottie Allen
Sold!  December 2023.      2000 U320; build # 5645
Our coach " Maxine"
Motorcade #  15922;  Escapee 150950; FMCA F330833; Boondockers Welcome;  Harvest Hosts;  Thousand Trails
'98 U320 from 2000-'06
USAF '62-'66

"Do not spoil what you have by desiring what you have not; remember that what you now have was once among the things you only hoped for." ―Epicurus

Re: 2002 U320 ISM Oil leak repair

Reply #6 –
That's a lot deeper than most of us will go into our engines, but nice to know that it can be done!  Excellent photo report!
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"It goes without saying..."

Re: 2002 U320 ISM Oil leak repair

Reply #7 –
Just for reference..

Cummins wanted over $3k to do this.. I bought the parts from ebay from 1 vendor, I could have saved over $100 if I would have shopped around but being all from 1 company made it easier for me if I have any issues..

Total time of actual work (not including wrestling tools and thinking ) say 8hrs and I am slow with a terrible back.... can be done with the right tools and with know how in about 3-4hrs max..

Edit to say i spent about $250 on this project and my time. So I equate it to about a $10k fix lol  with my time haa but I was a little nervous but it was really simple for the most part..

Re: 2002 U320 ISM Oil leak repair

Reply #8 –
Excellant article, i very much appreciate the part numbers and most importantly the photos !
You Deserve a Ten plus on this article !

Safe Travels

Dave ,
2001 U320 40ft
Build #5867
2003 Tracker
VE7DOD

Re: 2002 U320 ISM Oil leak repair

Reply #9 –
This is the harness picture .. the blue Oring's go around the base of the plug and have a tendency to leak.

Had to find these pictures.. but here they are.. this is at the rear of the ingine that would be right when you lift the bed. easy access..

You will need to remove the motor bracket (looks like the brackets they used to lower the engine) the harness enters the head right behind it..

Re: 2002 U320 ISM Oil leak repair

Reply #10 –
Those are some great shots of the valve lifting system.  I guess I've never seen a photo of the Cummins rocker arms...very interesting the way they sit at different angles.  All that mechanical stuff is packed in there pretty tight!
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"It goes without saying..."

Re: 2002 U320 ISM Oil leak repair

Reply #11 –
Quote from: Chuck & Jeannie –
Those are some great shots of the valve lifting system.  I guess I've never seen a photo of the Cummins rocker arms...very interesting the way they sit at different angles.  All that mechanical stuff is packed in there pretty tight!
I was amazed by the head and looking at the valves..