2015 F-250 CC 4X4 PSD. 86,000 miles.

​​​​​​. Hey everyone.

I have had the Rudy's CAC kit on the truck for a couple of years now. I just moved across the country, and was hauling a trailer that is about 11,500 lbs. The truck was running ok, but going into a Regen about every 100 miles or so. Looking under the hood, the metal pipe was slipping out of the boot on the top, so I loosened the clamp, re- inserted and tightened the clamp as tight as it would go. All seemed well.

Just got to my destination, and it slipped out again, but I did see a lot of black, oily soot on the metal part with the O ring in it at the connection with the throttle body. The metal clip is still there, but I can rock the whole assembly back and forth. Is this normal? I am going to get another clamp to see if this helps, but, unless the rubber O ring is worn, it seems to have too much play in it. The last pic shows the pipe slipping out of the boot, 1/4 inch in about 500 miles.

Appreciate any input, thanks.

 

I'm thinking that maybe the O-ring where the clip is could be pinched or not sitting right in the housing. That's where the soot is and where it's leaking. I bet the ECM sees the vacuum leak as a lean condition and probably dumping more fuel in?? So you're running rich?

 

I had a similar issue with my Mishimoto CAC kit earlier this summer. Was pulling a load on the expressway and noticed a lack of power and a higher than normal amount of boost, also had to use excessive throttle to maintain speed. Popped in my code reader while I was driving (I keep it in the center console at all times) and scanned for codes. I don't remember the code that popped up as "pending" (it had not set the check engine light yet) but after looking it up one of the problems could be an intake leak or CAC leak.

When I arrived at home I popped the hood and checked the CAC pipe and their was black oil all over the throttle body fitting like yours. I pulled on the fitting and it moved just as you describe. I knew this was not normal so I started checking the spring clip that fixes the metal housing to the throttle body and found the underside part of that spring clip was not fastened into the throttle body correctly. Apparently the Ford Tech that did some work on my truck didn't reconnect the CAC correctly at the throttle body. I cleaned everything up really good and refastened it making sure that spring clip was properly locked into place. All has been good since.

My suggestion is check that spring clip all the way around, it might not be seated correctly. I don't have an answer on the silicone slipping off the metal pipe other than maybe the band clamp is the incorrect size? There is a torque spec for those clamps.

 

That soot is new, was not there at the last oil change, maybe O ring is just brittle and worn out. The other side where the pipe is slipping out of the boot, I can only guess the clamp has lost some of its tension. I tightened that thing as far as it would go. All has been fine for the last 2 years, until now.

 

reminds me of my 6.0 days pf blowing hose off cac. when you go near 30l bs of boost steady
take a bit of alcohol and clean the crap out of the two mating surfaces, on the rubber and the metal .
then use CHEAP hair spray like white rain and spray both surfaces then re assemble while wet and torque the spring clamp
once the white rain dries...its like being glued on

 

The weird thing is, nobody has worked on this truck in the last year or so, except me doing maintenance. Just trying to understand if an O ring can just go bad. The clamp? Something else that just happened. It was fine for 2 years.

 

Weird things can happen I'd still look over it very closely. I don't think that O-Ring will go bad in 2 years. I've had mine installed for 4 years and all is fine.....and I tow 6500lbs daily.

I remember people with the rudys kit posting about cutting that spring down on the band clamps to get the correct torque on the pipe. It's possible it was just barely sufficient for 2 years and now it's just not enough to hold it tight. If the threads bottom out before you reach the proper torque then that's the problem.

 

I'll see if I can get a new clamp, as well as an o ring for the other side. I re-used the factory clamps when I installed the kit, because the Ford clamps looked to be better quality. The oily residue on the throttle body side bothers me more.