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Oil blow-by using Pac-Brake

Yahoo Message Number: 5911
On long downhills using my Pac Brake I am getting oil all over the toad. I know many people have had the orifice in the Pac Brake drilled out to a larger diameter to reduce pressure. One friend with the same coach as mine told me that this stopped the blow-by but drastically reduced the effectiveness of the Pac Break.

A Pac Brake rep at a show told me he would try and hook up a bottle over the end of the blow-by hose. I asked a tech at Cummins in El Cajon what could be done and he said he had seen several people use a bottle with ventilation holes cut in the bottle so there was no back pressure.
Has anybody else tried this? I think that a tall 1 gallon water botttle or bleach bottle attched with a hose clamp or zip tie would do the trick.

Any other ideas?

Bruce Bandemer
02 Allure 30757

Re: Oil blow-by using Pac-Brake

Reply #1 –
Yahoo Message Number: 5912
Hi Bruce,

I had holes drilled by Cummins NW in Colburg - still had some blowby.
Attached a pint container after adding a 6 in extension hose. Secured it with plastic tie wraps. A 1/2 in vent is required. I drilled 2 holes in the screw-on lid - container and lid are heavy frosted plastic with graduations on the side.
I purchased the container at the local grocery store. If you don't get the holes drilled, then a larger container may be required.
Fred Kovol

Re: Oil blow-by using Pac-Brake

Reply #2 –
Yahoo Message Number: 5913
David & Karen CA.
2000 Intrigue 11062
40 ft Single slide. PT
2002 Odyssey TOAD

Re: Oil blow-by using Pac-Brake

Reply #3 –
Yahoo Message Number: 5914
We have dragged our WHITE Odyssey up and down many hills in the past eighteen months and do not get any discernible oil on the front.

Our engine is the 350 ISC model built in late 1999.
Am I just lucky or is my Pac-Brake not as efficient as it should be?
I find it puzzling that a Cummins shop would physically modify the existing Pac-Brake. What does the Cummins factory recommend?

Is the Pac-Brake the same model between 1999 and 2002?

David & Karen CA.
2000 Intrigue 11062
40 ft Single slide. PT
2002 Odyssey TOAD

Re: Oil blow-by using Pac-Brake

Reply #4 –
Yahoo Message Number: 5916
Bruce,

I had a similar problem for about 5K miles after I changed the engine oil for the first time. When I refilled the oil I brought the level right up to the "top" of the full mark on the dipstick. At 5K miles and with the dipstick level at halfway between "full" and "4qts" below full, the blow-by magically ceased.
I now have 8K miles on that oil change and the dipstick level has not moved from where it was at 5K miles.

When I changed the oil it took a gallon more than the capacity stated in the manual. (IIRC it was the Cummins manual) At the time I thought the manual might be incorrect. Now I think maybe CC used too short a dipstick, and the blow-by was caused by over filling the crankcase.
I am going to leave it at "2qts low" and keep an eye on the oil level and the coach rear end.
Dave

2000 Allure 36'
#30444

Bruce B wrote:

Re: Oil blow-by using Pac-Brake

Reply #5 –
Yahoo Message Number: 5920
Dave,

Mine also seemed to blow out the first two qts, so now I run mine 2 qts from full mark.

Steve

Intrigue #10673

Quote from: Dave Hills \[br\
]
Bruce,

I had a similar problem for about 5K miles after I changed the
engine oil for

Quote
the first time. When I refilled the oil I brought the level right

up to the

Quote
"top" of the full mark on the dipstick. At 5K miles and with the
dipstick level

Quote
at halfway between "full" and "4qts" below full, the blow-by
magically ceased.

Quote
I now have 8K miles on that oil change and the dipstick level has
not moved from

Quote
where it was at 5K miles.

When I changed the oil it took a gallon more than the capacity
stated in the

Quote
manual. (IIRC it was the Cummins manual) At the time I thought the

manual might

Quote
be incorrect. Now I think maybe CC used too short a dipstick, and

the blow-by

Quote
was caused by over filling the crankcase.

I am going to leave it at "2qts low" and keep an eye on the oil
level and the

Quote
coach rear end.

Dave

2000 Allure 36'
#30444

Bruce B wrote:
>

> On long downhills using my Pac Brake I am getting oil all over the

toad. I

Quote
know many people have had the orifice in the Pac Brake drilled out

to a larger

Quote
diameter to reduce pressure. One friend with the same coach as

mine told

Quote
me that this stopped the blow-by but drastically reduced the
effectiveness of

Quote
the Pac Break.
>

> A Pac Brake rep at a show told me he would try and hook up a
bottle over the

Quote
end of the blow-by hose. I asked a tech at Cummins in El Cajon

what could

Quote
be done and he said he had seen several people use a bottle with

ventilation

Quote
holes cut in the bottle so there was no back pressure.
>

> Has anybody else tried this? I think that a tall 1 gallon water
botttle or bleach

Re: Oil blow-by using Pac-Brake

Reply #7 –
Yahoo Message Number: 5943
David & Karen,

Our coach does not have the optional oil reservoir, so the only level check is with the dipstick in the oil pan.

The oil was definitely coming from the crankcase breather tube as it was "wet" with oil up until the time the oil loss stopped. Now the outside of the tube is "dry" with a nice thick coating of oil/dust mixture on it.
There is an article at http://www.rversonline.org/01ConfCCCummins.html regarding pre '99 Cummins engines having a breather problem when using the PAC brake. The oil does not actually escape through the PAC brake, but rather through the breather. The high exhaust back pressure created by the PAC brake increases the piston ring blow-by, thus increasing the crankcase pressure and volume of gas flow through the crankcase breather. The crankcase breather is essentially an oil-gas separator. Apparently the older Cummins breathers could not handle the increased gas volume without blowing out some oil with it.

Dave

2000 Allure 36'
#30444

Re: Oil blow-by using Pac-Brake

Reply #9 –
Yahoo Message Number: 6008
There was a recall in my 2002 Intrigue#11451, to install another engine oil dip stick because the original one was marked incorrectly.

GaryBettig

Re: Oil blow-by using Pac-Brake

Reply #11 –
Yahoo Message Number: 6091
Dick,

I have a 400HP ISL.

Another question that that has come up is the need for a skid plate on single tax motorhomes. I have a 2002 Intrigue single tag 400HP ISL engine. According to the dealer, the motorhomes with the tag hang down lower there four needing a skid plate, so he says the single tags ILS motorhomes don't have the problem of bottoming out. As of yet I have not had a problem with mine.
Any thoughts on this please let me know.
Also is anyone going to the Balloon fest????????????? GBettig 2002 Intrigue 11451

Re: Oil blow-by using Pac-Brake

Reply #12 –
Yahoo Message Number: 6152
I think that I recall that it was the 400HP that had the oil pan problem. But I'm not sure. I have the 370 ISL and have not (yet) had the problem.

Dick May

2002 Intrigue, #11438