I pressure tested my Charge Air Cooler today. Kinda followed John and Chris's method. I gotta say this would be a lot easier with the CAC out of the vehicle. Anyhow, I used a piece of wood with rubber backing with a male air connection held tight to the CAC with a pipe clamp. On the other side I used the stock hose piece with a can stuffed in it. Held 45 psi with no leaks. Check out the third photo of the can. I'm thinkin' another 5 psi would have blown the back off of it! My advice to others that want to check your CAC; let someone else do it!
jor
Jor --Glad you were BRAVE!!!
Chris
Well done John see how easy it is to check pressure.
I did mine with it out due to repair of holes in cooling fins
JohnH
I would not run the pressure up more than peak turbo boost pressure plus 10%, and then time the leak down. My best guess is they all leak a little.
We use capped pvc with a valve stem fitted in one end.
Think when they did mine they went to 50lbs,Phred,it's a metal vessel why would it always have a leak?
About 600 lbs of force pushin on that can, come to think of it a selenoid valve, tee, potato and trigger and tailgaters would no longer be an issue.
Why do this test ? What indication is there that may be reason to suspect a leak ? I may have a problem and am not smart enough to know it. Have a great day ---- Fritz
Reminds me of the potato bazooka guns one of my kids used to make. Lots of fun blasting those babies into a brick wall.
I guess if you were getting insufficient boost it would be a good idea. I just wanted to do it for fun.
jor
With no boost gauge, in many cases it is difficult to tell you have a problem until significant loss of power. Don't know that I would do this as Preventive Maintenance, but if power issue or you are already under there working in the area, not a bad idea.
BUT (large BUT), as others have suggested, the force of 30 PSI on those end caps is significant. Do not be in the "line of fire" when pressurizing!
Visibly check it first and is the boost power will not get up to specs you may have a leaking CAC. I had 4 good sized bolt holes from a loose fuel cooler rattling it for years before I bought it. Massive difference after my fix. With the help from my Banks I get 32lbs which is great.
JohnH
I only put about 15 lb of pressure on mine had a gauge in line and once air was off just watched gauge drop then started looking for holes. I'm hard hearing so listening for air leaks don't work.
Chris
Regarding CAC, I've heard mention of the desirability of adding a second cooler in series with the first. This seems doable though it would take some piping. What would be the advantage of adding a CAC? Would it, in conjunction with some increased fueling make a safe power upgrade path? Would it support a larger turbo?
Wouldn't mind a power bump on my 300 Cummins 8.3.
Chuck,
Not too difficult to do a TEST to see if your current CAC is adequate or if "more is better".
And, on newer/electronic engines, this data is available on Silverleaf, Scangauge D, etc
Need a temperature probe somewhere between CAC exit and engine intake manifold or intake manifold itself. The newer engines tell you intake manifold temperature.
If within 10-15 degrees of ambient temperature, your CAC is doing what it should and extra cooling will likely do very little good.
If big delta between ambient and intake, start by really cleaning the CAC and radiator. Simple Green EXTREME is aluminum-friendly and works well.
If still a big delta, look at condition of CAC and/or supplemental CAC. I really doubt you will need to go to this step unless the CAC is bad. Said another way, suspect the CAC was properly speced.
Thank you Brett. Sometimes I tend to overlook the basic first steps and this is good information.
Not knowing what is normal is a problem. My m11 shows in the upper 20's at full revs up a grade. 27 or so 28 once. Is that good?
Call Cummins with your engine serial number. They should be able to look up max boost for your engine.
Cummins 800-286-6467
My cummins guy said 15 to 20 pounds under max load for a M-11
Chris
No, 27-29 are good numbers for an M-11. 15 to 20 is way low.