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"Leaky oil filter" update

August 05, 2018, 03:20:40 pm

I had early complained about a persistent problem I was having with oil filters that leaked.  This morning I degreased the mess caused by the oil and replaced the filter and added new oil.  I then started the engine to circulate the oil through the filter and checked to see if it was still leaking.  It turns out that the bolt (see photo) above and to the right of the filter is the apparent cause..
Does anyone know what the function of that bolt is?  I will need to get a gasket (or O ring if that is the case) and correct torque.
I could give it a good "wrench" to tighten it, but don't want it to come loose again.
The bolt in question is the larger of the two with "LE" marked on it.

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Re: "Leaky oil filter" update

Reply #1 – August 05, 2018, 03:33:34 pm

Sven,

I am not for sure (due to not being where I can see the pic. on a big screen) but I think that is the drain for the engine oil cooler. It should have a copper gasket under the bolt head not an "O" ring.  The "O" rings for the cooler are in the piping joints. That plug comes out to drain the last little bit of oil out before you remove the cooler, so you won't make as big of mess. 

Pamela & Mike

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Re: "Leaky oil filter" update

Reply #2 – August 05, 2018, 05:37:32 pm

Can't imagine a grade 8 bolt being used for a drain. Maybe it has been replaced by this bolt. A wider shot would be helpful.

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Reply #3 – August 05, 2018, 06:00:40 pm

Get on that Cummins site and look up the part on the parts breakdown.

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Reply #4 – August 05, 2018, 06:01:50 pm

Remove any washer if there is one. Replace with copper ring ideally , or nothing .

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Reply #5 – August 05, 2018, 07:29:14 pm

After having a while to think about this, that should be the plug for the before oil filter pressure tap/port.  On your year coach that may have an "O" ring seal rather than the old style copper gasket. (the old style was like a banjo bolt gasket)

Mike

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Re: "Leaky oil filter" update

Reply #6 – August 05, 2018, 07:53:04 pm

I gave the bolt a twist clockwise and found that it turned at an estimated 30-40 psi, indicating that it was loose and normal oil pressure of 40-60# would have leaked.  I pulled it out and found the remnants of a non metal washer.  I replaced it with a nylon washer and it seems to be doing the job.  I have copper washers on hand if they are needed.

This  does appear to be the oil cooler drain plug.  Learned something new today.  Thanks for the responses.

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Re: "Leaky oil filter" update

Reply #7 – August 05, 2018, 10:09:47 pm

Sven,

Follow up with Cummins (on line or at any dealership).  I would not take a chance with a nylon washer standing between you and your engine loosing all its oil!

Here is a good place to look: Cummins QuickServe Online

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Reply #8 – August 05, 2018, 10:51:08 pm

Yes, please use the copper washer.

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Reply #9 – August 06, 2018, 10:04:05 am

  My understanding is that the nylon drain washers allow for a good seal on a less than perfect surface and that they are designed to handle the heat.  The problem with non metal washers, from what I've read, is re-using them.  Before replacing my new nylon washer, has anyone had a problem with one in this type of application.

I will probably drain the oil cooler every time I change the oil to ensure that I've removed more of the old oil.

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Re: "Leaky oil filter" update

Reply #10 – August 06, 2018, 10:08:58 am

Sven,

Big difference in pressure between oil drain plug (zero PSI) and (at least what is likely) an oil passage where PSI with a cold engine can exceed 70 PSI.

Again, a little research on that Cummins site will give you the proper answer. 

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Re: "Leaky oil filter" update

Reply #11 – August 06, 2018, 12:14:15 pm

I registered with Cummins Quick Serve Online and am waiting for a response via email.  In the meantime, I called Cummins Care and was told that the nylon washer "should be fine".  To clarify, I asked if it was acceptable and was told yes.  I will wait for the email response to see if they corroborate.

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Reply #12 – August 06, 2018, 12:46:15 pm

Ya, I would feel much better using that website to look up the correct PN for your engine serial number.  That is the beauty of that Cummins application.

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Reply #13 – August 06, 2018, 01:03:30 pm

A part number would point to a specific washer, but not acceptable alternatives.  I am really curious about what the OEM material was; the washer I pulled off was not metal of any type.  Since it would not pull apart, I'm assuming that it was plastic.

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Re: "Leaky oil filter" update

Reply #14 – August 07, 2018, 06:46:24 pm

How long does it normally take to get a response from Cummins QuickServe Online?  I registered yesterday and asked about the oil drain gasket and have not received a response.  I'm glad for Cummins Care which has been pretty responsive to a phone call.

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