On my 99 f350 7.3, when towing a fifth wheel, I tow sometimes in cruise control. But when pulling a 6 or 7 % grade 3 to 5 miles long at 50 to 60 mph, in cruise, the after cooler hose that connects to the turbo will blow off. Its no problem to put back on , and I always check the clamps tightenss before a trip, but I am wondering if towing in cruise on a steep climb causes this problem. Doesnt seem to do it when the cruise not on pulling a climb. it does ok in cruise when towing on level or mile hills. thanks

 

Pull the boots/tubes and clean them all. Most likely has an oil build up in you tubing and intercooler. After cleaning, some have found that spraying inside of boots with hairspray will help keep them on. When you have it in a pull with a heavy load, your turbo is making max boost and it is making 18 to 22lbs of boost stock.

 

Oh yea, if you want to get rid of the oil build up, you can do the CCV mod. Search on this forum and see what is done.

 

Welcome to the forum.. I think if you do the CCV mod (rerouting of the crankcase gases) you would probalby eliminate that problem of the them blowing off.. I would stop the oil fumes from making the hose slick.. and would keep your engine alot cleaner too..

 

thanks i'm trying to find about the cvc mod, and i will clean the inside of hose

 

Simple mod really. The hose should not be blowing off. I made 11 27-29 PSI runs on the drag strip last week, all boots still tight. No hairspray used either, just CCV and good cleaning of boots.

 

This was a common problem on the early 99's. If you have an early 99 (without the foil wrap), and the hose from the turbo to the CAC tube blew off on the end that hooks to the tube, you need to get the updated CAC tube, as the early 99 gen tube is prone to distorting and letting the clamp slip. Before the updated tube became available, people would use a ball peen hammer to form a lip on the end of the tube to give it some extra rigidity and help keep the clamp in place.

 

Ernest that would make sense. Did the early trucks really come from the factory with smooth flanges on the CAC tubes?
My late '99 has a deep groove molded into the CAC tubes right under where the clamps are. I've pegged my 30lb guage before and regularly maintain 25 psi on a hill pulling the trailer.

 

As I recall, my OEM early 99 CAC tube wasn't completely straight like if you just cut the tube off with a saw, it terminated with a small rounded crimp where the end was rolled back under the inside edge. On the other hand, the Y manifold on the turbo outlet side has a large raised lip, that once you get the hose pushed over it and the clamp in place and tightened up, makes it impossible for the clamp to slip past the lip. I've not had the hose removed from my upgraded CAC tube so I don't know just what that end looks like, but it's been over 6 years now, and it shows no signs of slipping.

I'm sure Tenn has his good and tight, but surviving multiple runs at the drag strip isn't the "acid test" for these hoses blowing off. I've talked to many RVers who had the same experience that tom41 reported here. A long mountain grade seems to be the "Achilles heel" for these hoses. Every time I accelerate up to highway speed when towing is like a half hearted run down the drag strip as far as higher boost is concerned, but two years of this with one winter in TX and the other in FL, posed no problem. Then on the first trip headed west on the first really steep grade between Flagstaff and Williams the hose blew off at the CAC tube end, and no amount of cleaning and tightening would keep it from coming off again.

 

Here's what the new tube coupling point looks like:


As you can see, it has an indent where the clamp goes.

Joe

 

That also looks much more rigid on the end than my OEM, which would distort into an oval shape if the clamp was tightened too much.

 

Yeah the new ones just seem to hold up. I've never blown a tube, but only once I slid a clamp off of one of the orange boots and that was only because I wasn't careful enough about where the clamp was located. It was a little offset and the first hard acceloration popped the orange boot out from under it. After that I reset every clamp exactly centered where it should be and tightened it down nice and snug. No more blowoff.