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Topic: Oil Drain Plug Leak (Read 907 times) previous topic - next topic

Oil Drain Plug Leak

Just noticed a slow oil drip from the drain plug.  Haven't lost much oil since the last change and hope the plug was not cross threaded.  Now time to change oil once more and would look forward to recommendations on an effective solution. 
Fiddler
1959 Parris Island grad
40' 2001 U320 Build 5875
1999 Suburban K1500 toad
1986 Corvette Pacecar
ssoftail@comcast.net

Re: Oil Drain Plug Leak

Reply #1 –
Get a new gasket.  And, when the plug is out, check the threads of plug and pan.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Oil Drain Plug Leak

Reply #2 –
Fiddler,
My guess is when the oil was last changed, the gasket washer was not put back on the plug, this is a common happening when one is not paying attention to the job. 
Take the engine s/n to Cummins, they can get a new one quickly.
Better yet, have MOT send one to you.

Dave M

Re: Oil Drain Plug Leak

Reply #3 –
Also get the plug kit from cummins.  I had my threads just fall out when the plug was removed.  It is alum pan and threads and a steel plug.  Cost me a days wait to get the kit in.
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: Oil Drain Plug Leak

Reply #4 –
That just happened to us as well.  Drain plug was only hanging on by a thread.  Was told that the plug was tightened with too much torque damaging the threads. ( Previous change done at FOT).  I was told that the plug should be tightened only to 65 on a torque wrench.  We waited four days for the kit, but we are in Canada, so what can I say.
Rick & Colleen
2003 U320 38'

Re: Oil Drain Plug Leak

Reply #5 –
It must take extra skill to screw up a oil drain plug, seems more time in a trade school is needed ?
Dave M

Re: Oil Drain Plug Leak

Reply #6 –
On two coaches, I have had drain plugs so tight it took a pipe wrench and a piece of pipe to loosen them.  I guess shops are more worried about a lawsuit from a lost plug than they are losing a customer.

What is the ft/lbs of dragging 208 pounds through grass at 36 inches?

The drain plug always seemed to me to be a pretty primitive arrangement for something that might be removed and replaced 600 times during a diesel's life.

Matt B
Matt B
1998 u-320

Re: Oil Drain Plug Leak

Reply #7 –
Guess I need to laugh, I thought the oil drain plug was "Idiot Proof", See I am wrong again.  In the factory shops, Cat, Detroit Diesel, Cummins etc,  things like this would get you fired, today they seem to be happy they can sell him as a tech.
Why, I trust very few to touch my equipment today.
Dave M

Re: Oil Drain Plug Leak

Reply #8 –
The drain plug on the M11 is steel and it mates to threads in the aluminum block.
Aluminum threads are very easy to strip if the rather large plug is not tightened with a torque wrench.

The drain plug threads in the block of my M11 were so badly stripped that on the first oil change I managed to keep the plug in by adding teflon thread tape to the teflon thread tape already there. I was not comfortable with wondering if plug would fall out, and it did drip some, so I decided to tap the hole larger and install a Fumoto drain valve.

I taped the drain hole to 26mm by 1.5 which is 1.0236 inch by 17 tpi. This had little more threads than the original 1 inch by 18 tpi hole. I then ordered a 1 1/8 inch tap and Fumoto valve. I tapped the drain hole to 1 1/8 by 12tpi and obtained perfect threads, so installed the 1 1/8 Fumoto valve. Now the aluminum threads are good for life because there is no need to ever remove the Fumoto valve.

The one concern I had about the drastic tpi change (from 18 to 12) was the strength of the threads. I researched engineering papers on thread strength and found that in aluminum, 12 tpi is stronger than 18 tpi. So why would Cummins use the non-standard 18 tpi rather than the much more common 12 tpi. It is much easier to obtain good threads at 18 tpi than at 12 tpi, particularly when using high speed equipment.

I have available for sale: M26 x 1.5 tap and M26 x 1.5 Fumoto drain valve.
I also have for sale taps for M27 x 2 and 1 1/8 x 12.

Note that at some point in time the oil filter for the M11 changed from ANC threads to metric (my 1996 is ANC) and I suspect that the drain plug was converted to metric at the same time.
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Oil Drain Plug Leak

Reply #9 –
My last oil changes were done at Cummins so you would think they could do it right too.  But it was not the case.
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: Oil Drain Plug Leak

Reply #10 –
Quote from: P. Wyatt Sabourin –
The drain plug on the M11 is steel and it mates to threads in the aluminum block.
Aluminum threads are very easy to strip if the rather large plug is not tightened with a torque wrench.

The drain plug threads in the block of my M11 were so badly stripped that on the first oil change I managed to keep the plug in by adding teflon thread tape to the teflon thread tape already there. I was not comfortable with wondering if plug would fall out, and it did drip some, so I decided to tap the hole larger and install a Fumoto drain valve.

I have no plans to do this, but I am really curious.  Do you remove the pan?  If not, how do you remove chips in the pan?  My thoughts were either vacuum and a flexible tube, or dump oil in and flush the pan out.  A magnet would be pretty useless, I guess...

Matt B
Matt B
1998 u-320

Re: Oil Drain Plug Leak

Reply #11 –
I was concerned about chips in the pan.
I did not remove the pan.
Oil continues to drip for quite a while after removing the plug and tends to wash out chips.
Gravity tends to bring chips out also.
Hole is large enough to reach a finger through to feel for chips and to fish with bent wire.
There were surprisingly few chips in the pan.

The more difficult part was stabilizing the tap so that it did not just bore a hole like a drill bit would.
I used a nail through an 8 foot 2x4 braced against tranny with a floor jack on one end and held by a person on the other. The nail fit into the dipple on the shaft end of the tap - worked very well to get threading started.

Question: What comes in a Cummins Oil drain plug kit?
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Oil Drain Plug Leak

Reply #12 –
Wyatt,
Sure understand and like the idea of stabilizing the tap with the 2X4 w/nail, makes sense to me and love it.

Just to add some confusion, the oil filter for the ISM has been the LF9000, it now is the LF9070 Filter.  No idea about the older M11 series filter. 
Nothing stays the same anymore.
Dave M

Re: Oil Drain Plug Leak

Reply #13 –
The threads for the ISM filter are different than the threads for the M11.
ISM Oil Filter is LF9070, which replaced LF9001 and it has metric threads.
M11 Oil Filter is LF9009, which replaced LF3000 and it has ANC threads.
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Oil Drain Plug Leak

Reply #14 –
Yes, the LF 9070 is the longer filter like the LF9000, while the LF9001 is a compact or reduced clearance model (shorter) and for sure on the LF9009 / LF3000, Seems they keep changing specs and prices, the LF9000 cost me $25.50, now the LF9070 is $30.50
Heck a few years ago, the LF3000 cost in the $25.00 area, and after market (Wix, NAPA) sold for $70.00 area.  Why I stay with Fleetguard.
We buy by the case, so price does count.
Seems profit is the major issue here.

Dave M

Re: Oil Drain Plug Leak

Reply #15 –
Quote from: oldmattb –
I have no plans to do this, but I am really curious.  Do you remove the pan?  If not, how do you remove chips in the pan?  My thoughts were either vacuum and a flexible tube, or dump oil in and flush the pan out.  A magnet would be pretty useless, I guess...

Matt B


Matt,

Your Caterpillar engine has a steel oil pan, not aluminum, so striping the soft aluminum with a hard steel drain plug is not an issue.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020
 

Re: Oil Drain Plug Leak

Reply #16 –
An established way to collect tap shavings is to put grease on the tap for the chips to stick to.