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Topic: Crank Case Vent Tube - Modification to Catch Vented Oil? (Read 3502 times) previous topic - next topic

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #25 –
Quote from: wolfe10  Do NOT top off oil unless oil level is at or below the ADD mark (on a calibrated dip stick).
[/quote
uote]w

Am wondering how far below the ADD mark does Cat recommend running while feeling safe, and wonder why Cat seems to have issues with correct dip stick for the engibe ?

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #26 –
My ISB 5.9L Cummins (01' Dodge 1 Ton/40' Gooseneck 36,000 lbs. gross) has 390K currently and uses no oil when it's 2.5 Qts. low.  It took 225K to get stable (broke-in/no blowby).
It runs a little below the add (hash mark) on the dip stick and uses no oil until serviced @ 8/9K. 
Any more oil and it blows out.

In the early 90's I had the same design series (semi) that took over 300K before it broke in and used no oil if it was kept 4 qts. low.  Service was every 18/20K and it used maybe a pint.  It was running better when I sold than when it was new. 
Before that KT600 Cummins, Big Cam Cummins, Series 60 Detroit, 3406 Cat, etc. & none of them liked being full of oil.. they all took a couple of hundred thousand miles to break in.
Thank you Rotella.. pc 











S/W Houston 95" U320C SE/40' 
Build #4778  Cummins M11
Repairs & Covered RV Parking (BAO)
PPL is close..

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #27 –
Quote from: Dave M –
[quote author=wolfe10  Do NOT top off oil unless oil level is at or below the ADD mark (on a calibrated dip stick).
w

Am wondering how far below the ADD mark does Cat recommend running while feeling safe, and wonder why Cat seems to have issues with correct dip stick for the engibe ?

I'd suggest fill it up and if none gets blown out you are good to go. 
Early on there were no low/full marks on a dip stick.. you typically filled, then scribed the stick at the first oil service. 

How many gallons are recommended for your Cummins?  pc
S/W Houston 95" U320C SE/40' 
Build #4778  Cummins M11
Repairs & Covered RV Parking (BAO)
PPL is close..

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #28 –
Quote from: Dave M –
[quote author=wolfe10  Do NOT top off oil unless oil level is at or below the ADD mark (on a calibrated dip stick).
w

Am wondering how far below the ADD mark does Cat recommend running while feeling safe, and wonder why Cat seems to have issues with correct dip stick for the engibe ?

I never ran below the add mark and do not recommend it.  I understand your point. 

So, probably better stated as:  "Do not add oil unless oil level (as checked at least 30 minutes after engine shut down) is DOWN TO the add mark.  But, clearly this would also mean that you would add oil if below the add mark.  Perhaps a matter of semantics???
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: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #29 –
Here are photos of our re-calibrated dipstick, made about 10 years ago. Tube was cut and a brass compression fitting used to hold the two pieces together.

Also noted is a fix for a broken dip stick tube bracket. When the bracket broke, we found that there was way too much tension needed to force the tube back into the original position, so we added an extension to the mount allowing the tube to be positioned in a relaxed position. We also have added two support brackets near the bottom of the tube to help prevent vibration breakage at engine block.

I see the photo also shows our string that we have on every filler cap, to help us not having to look for replacements.

Photo also shows the 'vent' hose we added to the compressor governor to keep dirt, water, dust, etc from getting into the unprotected top vent hole.

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #30 –
@Barry Are those snacks on the frame rails for rodents so they're not tempted to chew your wiring?

see ya
ken
The selected media item is not currently available.ken & dori hathaway & Big Agnes
🍺1992 U300 GrandVilla WTBI #4150 FOT FBP 2011
✨6V-92TA DDEC Parlor Coach 350HP Series 92
🏁2011 Nissan XTerra Pro-4X

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #31 –
Ha! I was going to ask the same thing.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #32 –
Ken & Richard, you guys have good eyes. . .

Yep, the toilet bowl snacks are out when we park, and there are a few more here and there that stay in place all the time. Just not sure how to keep critters from feeling at home in and around the motorhome.

Figure I never saw any unwanted critters in a home toilet bowl, so maybe it would work in the engine area. Hope they don't think it is good place to use as their toilet. Tried moth balls, but they didn't last long and smelled too much. We have seen foot prints in the dust on those engine compartment rails, so that is why we put the toilet bowl deodorants on the ledge.

Heard that having lights on at night may be one of the best ways to keep them away.

We are going to park at the Albuquerque Balloon Fiesta this weekend and those deterrents should come in handy.

How about our new engine compartment lining? I see it made a nice background for the two photos.
B&C

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #33 –
Barry, the lining looks very nice. That's on my to do list. We use lots of Irish spring soap bars thru out the bays and seems to work. On the plus side it smells good!
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #34 –
I finished my addition of a simple, inexpesive catch cup last weekend that I think will help keep things clean.  It's basically a $5 Nalgene bottle from Academy, a few feet of wire cable as a harness and a couple of D-ring clips.  I added a stainless steel wool kitchen scrub pad in the cup to help capture oil vapors.  On my engine, there was a convenient vent tube retainer clamp about 8" above the bottom of the tube that secures the tube to the crankcase.  The wire is routed over this clamp, suspending the catch cup at the right height on the tube.  The whole thing cost about $10, was very easy to install and will also be easy to monitor and remove for draining.  Next step is to properly calibrate the dip stick and stop overfilling but I like this as a permanent backup solution.

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #35 –
A recent thread dealing oil blow by and breather tubes reminded me that I should update this post with my final results on an attempt to mitigate oil coating the back/bottom of my engine and frame.  The catch cup was a great idea that, for me, caught NOTHING!  After several trips it was dry as a bone.  As it turns out, based on diagnosis by Mustang Cat, my oil was coming from a leaking timing cover, not the breather tube.  They removed the catch cup and recommended against its use in order to prevent any back pressure in the crank case.  Catch cup experiment over.

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #36 –
Crankcase breaker "oil catchers" are fine as long as you have the same or more sq inches of outlet as the OE 1" ID breather.

Have done this on Caterpillar and Cummins engines.  Surprised you got zero oil-- an ounce or so per 5k miles is pretty normal.
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: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #37 –
Yeah, I think the cup was sized ok for proper venting but Mustang wasn't comfortable with it.  It wasn't catching anything anyway so I was fine with removing it.  I wish the breather had been the source of the oil because the timing cover turned out to be a much bigger job...that has not been done yet.  The small amount of oil and the mess it's causing don't really justify the repair cost, which was close to $4k.  For now I'll deal with a few drips under the coach and continue to monitor it.

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #38 –
Brett,is it worth mentioning that most of the cats I have seen starting at 3306 on up to the biggest 3608 have 2 marks on the dipstick
one for full when not running and one for full at idle,these are nat gas,I would think the diesel would be the same.Maybe
somehow these 2 marks are coming into play.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #39 –
Quote from: John44 –
Brett,is it worth mentioning that most of the cats I have seen starting at 3306 on up to the biggest 3608 have 2 marks on the dipstick
one for full when not running and one for full at idle,these are nat gas,I would think the diesel would be the same.Maybe
somehow these 2 marks are coming into play.

At least in RV applications, the oil dipsticks are the same as most vehicles:  full/add.  As with any large diesel engine, one needs to wait at least an hour after shutting off the engine for all the oil to drain back to the pan.  Best to check in the morning (cool and all back in pan).

But, neither Caterpillar nor Cummins provide dipsticks for RV's.  So, best to CALIBRATE IT!!!
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: Crank Case Vent Tube - Modification to Catch Vented Oil?

Reply #40 –
If you are getting oil out of the breather tube in any appreciable quantities it is an indication of internal wear and the resulting blow by of oil. If you are catching 1/4 cup get it checked out.  Better sooner than a later rebuild.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN