Thanks DD and Rich for your help:
My exhaust manifold leak is at the #1 or #6 cylinder, the cylinder furthest away from the back of the motorhome. The leak is at the gasket where the exhaust header bolts to the manifold. I over torqued it when I changed the turbo. The way I noticed the leak was seeing some black residue in that area around the gasket. I did a bubble leak test back when I changed the turbo around 2 years ago and the leak did not seem that bad, that was at idle speed and may have gotten worse. It was very disappointed to see after all the work it took to change the turbo, I could not check for leaks until everything was back together. I did buy a very expensive and very high temp sealant and applied the best I could around the leak. I do not believe it really helped. Not sure the exhaust leak is only problem, since I had the same climbing problem before I changed the turbo? The lack of power was the reason I changed the turbo and Cummins told me it was bad. I do not believe there was an exhaust leak when the old turbo was on.
I have checked all the hose clamp fittings, I have not checked the hoses themselves for leaks, so I will make sure to do that. How do I check to see if the turbo is free to spin? I assumed it was working since I had boost going down the road.
I have not checked the air compressor hose; will the water leak test be adequate to check for the leak? I will do some research to figure out how to check the output pressure of the fuel lift pump. Any good web sites I should check out for how-to info?
With the anxiety of the motorhome not moving up the hill I failed to notice what the engine RPM is reading, I am thinking the engine does not even rev up; it just sits there and then slowly starts to roll forward. It is really is like nothing happens when I press the throttle. Sure hope it’s not the torque converter, I have not noticed any kind of slippage. Any checks to verify this? I have changed the filters and fluid in the tranny--Allison 6 speed. It has a fluid level check and it does read OK and seems to shift fine on the road. Should I look into a potential throttle issue? It has the Electronic throttle control.
FYI- I did have another issue once where I had no power and found the exhaust brake was sticking closed. It released with a couple of sprays of WD-40 on the plunger shaft. I always check it now before I leave to insure it is not stuck closed. I was on the road from a campground when that happened not at my home on the hill.(As I mentioned, I do make sure the exhaust brake is not stuck shut before I back out of my pole building so I don’t believe it has anything to do with my power issue.)
Thanks you again, all help is greatly appreciated.
Dave