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Cummins oil leak - dip stick calibration

Yahoo Message Number: 21519
A common cause of excess oil blowing out of the breather is an improperly calibrated dip stick resulting in an overfill situation.
Since there is no such thing as a "standard dipstick" in a custom built motorhome, a critical step in the oil changing process is to calibrate the dip stick. It is an easy process and one that is almost always forgotten by the average grease jockey.
The process to calibrate the dip stick is easy. First, drain the oil while it is warm or hot and remove the oil filter. Be sure to let every droplet drain completely.

The next step is the most important... read your Cummins owners manual to see the manufacturers specification for the correct number of quarts to be used for an oil change for your engine. Let's say for example it is 26 quarts. Install a new filter prefilled with oil -- and let's say that it takes 2 quarts to pre-fill the filter. Open the engine oil fill cap and pour in the remaining 24 quarts. Now you know for a FACT that you put exactly 26 quarts in the engine and filter.

Next, start the engine and let it run to circulate the oil completely and eliminate any air pockets. Stop the engine and check the oil level. Take a file and place a scratch on the dip stick at the top of the oil -- THIS is your custom FULL LINE for your coach and your custom made dip stick. IGNORE the standard markings on the stick. Use only your mark as your indicator of "full".

Now, if you have excess blow-by from the crankcase breather, you'll know that it is NOT caused by an overfill situation, but from some other cause.

Hope this tip helps. It is the process that Cummins taught me when my first oil change was done on my coach.

Regards,
Bob

2003 Intrigue

Re: Cummins oil leak - dip stick calibration

Reply #1 –
Yahoo Message Number: 21522
Yep ... what he said ...

I had this post all prepared ... glad I checked before posting, he said it better than I was going to.
I went thru this with our Dutch Star ISC350. A thread on the Newmar site covered this long time back, and its critical.
Also, we learned that it is very common for a leak to develope where the hydro pump bolts to the front engine flange (lower right when looking from the rear). A neighbor had this happen to his ISC350.

Our leak turned out to be a leaking pan gasket at back of the engine, right by the hydro pump of all places.
We put a bottle with vents on the blow by tube and it did catch some oil, but this was before the discovered the leaking pan gasket.

John and Terry
2005 Affinity

Quote from: rvrobert2003
>

A common cause of excess oil blowing out of the breather is an > improperly calibrated dip stick resulting in an overfill

situation.

Quote
Since there is no such thing as a "standard dipstick" in a custom > built motorhome, a critical step in the oil changing process is to > calibrate the dip stick. It is an easy process and one that is > almost always forgotten by the average grease jockey.

The process to calibrate the dip stick is easy. First, drain the

oil

Quote
while it is warm or hot and remove the oil filter. Be sure to let > every droplet drain completely.

The next step is the most important... read your Cummins owners > manual to see the manufacturers specification for the correct

number

Quote
of quarts to be used for an oil change for your engine. Let's say > for example it is 26 quarts. Install a new filter prefilled with > oil -- and let's say that it takes 2 quarts to pre-fill the > filter. Open the engine oil fill cap and pour in the remaining

24

Quote
quarts. Now you know for a FACT that you put exactly 26 quarts in > the engine and filter.

Next, start the engine and let it run to circulate the oil > completely and eliminate any air pockets. Stop the engine and

check

Quote
the oil level. Take a file and place a scratch on the dip stick

at

Quote
the top of the oil -- THIS is your custom FULL LINE for your coach > and your custom made dip stick. IGNORE the standard markings on

the

Quote
stick. Use only your mark as your indicator of "full".

Now, if you have excess blow-by from the crankcase breather,

you'll

Quote
know that it is NOT caused by an overfill situation, but from some > other cause.

Hope this tip helps. It is the process that Cummins taught me

when

Re: Cummins oil leak - dip stick calibration

Reply #2 –
Yahoo Message Number: 21523
Sorry ... I meant the air compressor, not the hydraulic pump ...

Lower right side when looking from the rear ...

John and Terry
2005 Affinity