Can anyone tell me the steps to activate the built-in exhaust brake on the 2010 F250 6.4 PSD? I can't find this in my owner's manuals and I'm getting conflicting info from the dealer. The dealer says to just tap the brake pedal one time to set the brake, but I can't help but believe there is more to it than that. Some guys might want to descend the hill at 30 MPH and another might want to go 50. Any info will be appreciated. Also, maybe some of you can tell me where to find this in the owner's manuals ??
Ford built-in exhaust brake
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Shark is correct--check the manual for operation of the Tow/Haul mode. You can drive with it on or off at any time--suggest you try driving around with it on and see how it affects downshifts when approaching a stoplight, or whenever you use the brake. It is NOT an exhaust brake, just a computer program to mod the shift patterns of the TorqueShift trans.
Joe
Joe
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I never trusted the Tow/Haul to downshift for me on really steep grades. It's ok for most towing, but on really steep grades, I manually slowed down and downshifted. This worked pretty well.
And there is no exhaust brake on your rig. If the dealer said there was they're retarded.
And there is no exhaust brake on your rig. If the dealer said there was they're retarded.
Wow! I guess I totally misunderstood about the exhaust brake being built-in. That being cleared up, let me ask you this...how effective is the downshifting in the Tow-Haul ? We are going up to NC in October and out west next spring, pulling the 13K Lb fiver. Is the Tow-Haul mode enough to keep me from burning my brakes on the long grades in Colorado, etc?
I have a 12k 5th and in tow/haul mode I set the cruise control and the engine will keep it at set speed going down steep hills. Try driving around in tow/haul mode without your trailer and you will notice the truck shifting down when you apply the brake, then try going down a hill in cruise control and tow/haul mode, it should stay at the same speed, then switch off tow/haul mode and the truck will pickup speed. The truck will do what it can to save your brakes, but can only do so much.
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It will be fine.
Having just driven from Phoenix to West Yellowstone towing our 9K fiver and having driven some serious mountain grades, I'm fairly impressed with the tow/haul mode. It will indeed maintain your speed on downhills. It will usually downshift by itself but tapping the brake will make it downshift. The only issue I've had is that if you brake even moderately hard it will downshift again, usually rather hard, and really wind up the rpms, like 3500 or so. And then, if you give it throttle it will not upshift. I have to take it out of tow/haul to make it upshift. The first downshift is fine and it will upshift with a touch of throttle. Also, it seems to learn and works smoother with use (except for the secons downshift...doesn't seem to inprove that.
I've been browsing around looking for info on the Tow/Haul mode and found a writeup on the 2008 Ford 6.4L PSD, which included the following statement:
"Getting the truck and payload moving is one thing. Slowing that pack of ponies down is another. If you are towing and running heavy loads in the [COLOR=#0072bc !important][COLOR=#0072bc !important]truck bed[/COLOR][/COLOR], the Tow-haul gear selection in the Ford TorqShift five-speed automatic transmission is a marked benefit to safety and driver confidence. At the Michigan Proving Grounds outside Detroit, we hauled loaded trailers and loaded truck beds up and down as real-world road grades of the caliber likely to be found anywhere in North America. The tow-haul gearing changes shift points under acceleration, allowing the 6.4L Power Stroke to maintain higher rpm’s, stay up in the power range, and maintain gear selection as your rig crests the hill. On the downhill side, Ford’s TowCommand System works with the tow-haul transmission feature to downshift when the brakes are applied; allowing Ford’s true engine-compression braking system to slow truck and trailer, and maintain a steady speed downhill. In the actual “seat-of-the-Levi’s” experience, this capability was, perhaps, the most impressive benefit, along with the consistent power delivery of the dual turbochargers, position the 2008 [COLOR=#0072bc !important][COLOR=#0072bc !important]Ford Super Duty[/COLOR][/COLOR] truck as a class-leading work and fun truck."
This clearly says that it DOES have engine braking as part of the Tow/Haul mode! Now I'm really confused! What say ye, Ford gurus?
"Getting the truck and payload moving is one thing. Slowing that pack of ponies down is another. If you are towing and running heavy loads in the [COLOR=#0072bc !important][COLOR=#0072bc !important]truck bed[/COLOR][/COLOR], the Tow-haul gear selection in the Ford TorqShift five-speed automatic transmission is a marked benefit to safety and driver confidence. At the Michigan Proving Grounds outside Detroit, we hauled loaded trailers and loaded truck beds up and down as real-world road grades of the caliber likely to be found anywhere in North America. The tow-haul gearing changes shift points under acceleration, allowing the 6.4L Power Stroke to maintain higher rpm’s, stay up in the power range, and maintain gear selection as your rig crests the hill. On the downhill side, Ford’s TowCommand System works with the tow-haul transmission feature to downshift when the brakes are applied; allowing Ford’s true engine-compression braking system to slow truck and trailer, and maintain a steady speed downhill. In the actual “seat-of-the-Levi’s” experience, this capability was, perhaps, the most impressive benefit, along with the consistent power delivery of the dual turbochargers, position the 2008 [COLOR=#0072bc !important][COLOR=#0072bc !important]Ford Super Duty[/COLOR][/COLOR] truck as a class-leading work and fun truck."
This clearly says that it DOES have engine braking as part of the Tow/Haul mode! Now I'm really confused! What say ye, Ford gurus?
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Not a Ford guru, but I always thought compression braking was what I did in our corvette when I down-shifted. To me exhaust braking was what the big rigs did when they pulled on the j-brake. I can see how you can make the argument that they're both the same (in principle), but I know of no flapper in the exhaust to help you stop (except for the dpf, of course ). David
). DavidI may be wrong in using the term "exhaust braking", but you can see in the article on the 2008 that it refers to "engine braking", not just downshifting in the tranny. I wish we could get some of the Ford-certified techs on here to clarify this. Thanks for your reply!Not a Ford guru, but I always thought compression braking was what I did in our corvette when I down-shifted. To me exhaust braking was what the big rigs did when they pulled on the j-brake. I can see how you can make the argument that they're both the same (in principle), but I know of no flapper in the exhaust to help you stop (except for the dpf, of course
Jminyard: Using an engine and transmission for slowing down a vehicle and an exhaust brake are two different things. Mark Kovalsky that posted above in your other post, was a former Ford transmission engineer, and knows your transmission in and out. I’ve been to the Michigan proving ground, they’re impressive, but in the real world you’re not testing someone else’s truck and they don’t test with their wife beside them LOL.
I’ll try to explain. Exhaust braking closes off (blocks) the exhaust manifold, leaving the exhaust gases in the cylinders to compress and slow down the engine. Engine braking doesn’t allow fuel to be injected into the cylinder, so a vacuum is created in the cylinders, which slows down the engine, which is connected to the transmission and slows the truck down.
I’ll try to explain. Exhaust braking closes off (blocks) the exhaust manifold, leaving the exhaust gases in the cylinders to compress and slow down the engine. Engine braking doesn’t allow fuel to be injected into the cylinder, so a vacuum is created in the cylinders, which slows down the engine, which is connected to the transmission and slows the truck down.
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Engine braking is what happens when we downshift without applying the throttle.
Exhaust braking is an entirely different thing.
Exhaust braking is an entirely different thing.
Thanks guys. I understand what you're saying.
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and it works on real 5er's too. I've taken my 18000# 5er down Saluda grade on I26 and Fancy Gap at I77 on the NC VA line and I'm still here.
You can't catnap while doing it but these trucks are very capable.
You can't catnap while doing it but these trucks are very capable.
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There is no separate exhaust brake. The turbocharger is a variable geometry unit. That means the opening from the exhaust manifold into the turbocharger can be varied by the PCM. When braking is required the tow/haul mode downshifts the transmission and closes the opening into the turbocharger to add a lot of exhaust pressure. This backpressure adds a lot of drag to the engine, which is braking force.
The transmission doesn't create braking. There is nothing in the trans that can be used for braking. It's contribution to engine braking is keeping the engine at higher speeds so that the exhaust braking is more effective.
The dealer is correct. Imagine that!
Turn on tow/haul. When you need engine braking, tap the brake pedal hard enough to turn on the brake lights. The PCM watches the brake lights switch to know when to downshift. If you need more braking brake harder until the trans downshifts again. It will stay in the lower gear even if you release the brake pedal.
It will adjust for any downhill speed by selecting the proper gear to mainting the downhill speed. The person that wants to be at 30 MPH will be in a lower gear than the person that wants to be at 50 MPH.
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Just be prepared for the time the trans downshifts into 2nd at 30mph and the tach hits 35-3700--that will get your attention!!! I find that the T/H works too well sometimes and I have to kick the T/H out and start the process over. Just something to get used to, but I have full confidence that it helps a lot going downhill with a load.
Joe
Joe
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