My U225 has nothing except the pedal brake and I'd like something in addition on long and steep grades but I don't know what will work with my coach. I've got the 5.9 Cummins. Any suggestions?
Our '93 U-240 CAT has a PACBRAKE retarder, you might check with them. Would not be without one out here in the West! 1.800.663.0096 or Google.
Pacbrake seems to be the best exhaust brake on the market. How effective it is depends on five factors, displacement, rpm, bypass orifice size, transmission lockup, and how many PSI of back pressure your exhaust valves can handle. The mountain tamer exhaust brake I have is no longer made but works ok on my motor which is limited to 35 PSI I think. Never touch the brakes very often on grades or at other times to slow down. My transmission is only locked up in third and fourth where an exhaust brake is more effective.
Thank you for the replies gentlemen but my understanding is different engines need different equipment. I'm hoping to hear from someone with a 1993 U225 with a 5.9 cummins.
PacBrake Exhaust Brake Dodge 5.9L Cummins 89-98 12 Valve Turbo Diesel (https://puredieselpower.com/dodge-products/1988-1998-dodge-5.9l-cummins-pacbrake-exhaust-brake.html)
Diesel Exhaust Brake Brake Kits | Thoroughbred Diesel (http://www.thoroughbreddiesel.com/exhaust-brake.htm)
I installed a Jacobs exhaust brake in my 1992 Dodge with your engine, then after 350K miles switched it to my 1998 Dodge which now has 275K miles. The only problem I've ever had was a failed Bosch relay. I also installed the increased back pressure exhaust springs to maximize the effectiveness of the brake.
As was mentioned there are several important points here. The 643 Allison trans locks its torque converter halfway through third gear and all of fourth gear. Max effectiveness without trans heating is locked up.
The 360 cu in motor power and retardation from a exhaust brake are proportional.
Thank you for the comments. I'm trying to understand all of this. What happens when the torque converter locks?
Bob, would you or another gear head explain "Lock-up"? I've heard the term many times, but don't know if I do that off the shift pad by downshifting, or does the Allison do it on it's own? Thanks, M
Allison does it on its own. You can't manually control it. When it is unlocked torque multiplication takes place and heat is generated. When locked up the input to the trans. is locked to the engine rpm and no heat build up. What Bob was saying is when in the upper half of third gear and all of fourth the Pac Brake would have maximum efficiency.
Our '93 U225 with the 5.9 Cummins had a Pacbrake. It worked very well.