Proper Use Of Volvo Jake Brake

[Cotreker]

I want to make sure that I am using the Jake brake correctly going down steep mountain hills.  Would like to stay in control at 35 to 40 mph.  Should I be using the cruise control while having the brake switch activated?  My HDT has a two position switch where should it be set?  What is the highest RPM I should let the truck run at?  What works best and or how do they work best?

2006 Volvo D12, Eaton Fuller 10 speed manual

[Nigel]

No problem using cruise with the  brake.  Leave the brake on with the cruise when in hilly terrain and you will find the brake comes on when your speed increases to about 5 mph over the set speed going downhill.  I tend to leave my brake off when not using the cruise on the flats as every time you lift the throttle to coast the brake comes on and then you must get back on the throttle, not as fuel efficient but that is just me.  I have no advice for which position to use as mine only has one and that is exhaust only.  Going down the steep grades I’ll let my rpm run up to about 2100 and then give the service brakes a good squeeze and bring the rpm down to 1400 and then get off the brakes and let them cool and repeat.  I was taught to do this rather than riding the brakes to maintain a constant speed and risk overheating them.  I am sure there will be other opinions.

 

Nigel

[RickW]

The higher the RPM the more effective the brake will be.  Also the lower the gear, the more effective the brake will be.  In 10th @1500rpm the brake will seem gentle.  In 5th @1500rpm it feels like it is going to throw you through the windshield when on high.

As for position, I always found myself flipping between the two going down the grade.  Basically when I was slowing down to a speed I felt was too slow, I would switch the position from high to low.  On less steep grades I would often switch between low and off.

What you will find is with the exhaust brake it is not a set and done.  You are going to find yourself adjusting the setting frequently for the moment.  Once you get it figured out on how it works best for you, you will find your foot is only on the service brake for complete stops.

[BlueLghtning]

Pretty much the same as above. I don't know if you have an actual Jake brake or just exhaust brake. I have a 3 position Jake brake that engages 2, 4 or 6 cylinders on my Volvo 610 with a Detroit 12.7. I use the 4 & 6 cylinder position the most and adjust as I want to control my speed descending. With a manual transmission, I certainly try to make sure I'm in the proper gear before starting that descent. Generally speaking, you go down in the same gear you came up, but early on I played it safe and sometimes used one gear lower. I've gotten much more comfortable even having to adjust which gear I'm in if need be. A lower gear that keeps your RPM's up higher definitely helps control your speed better. 

[beemergary]

42 minutes ago, BlueLghtning said:

Pretty much the same as above. I don't know if you have an actual Jake brake or just exhaust brake. I have a 3 position Jake brake that engages 2, 4 or 6 cylinders on my Volvo 610 with a Detroit 12.7. I use the 4 & 6 cylinder position the most and adjust as I want to control my speed descending. With a manual transmission, I certainly try to make sure I'm in the proper gear before starting that descent. Generally speaking, you go down in the same gear you came up, but early on I played it safe and sometimes used one gear lower. I've gotten much more comfortable even having to adjust which gear I'm in if need be. A lower gear that keeps your RPM's up higher definitely helps control your speed better. 

 

42 minutes ago, BlueLghtning said:

Pretty much the same as above. I don't know if you have an actual Jake brake or just exhaust brake. I have a 3 position Jake brake that engages 2, 4 or 6 cylinders on my Volvo 610 with a Detroit 12.7. I use the 4 & 6 cylinder position the most and adjust as I want to control my speed descending. With a manual transmission, I certainly try to make sure I'm in the proper gear before starting that descent. Generally speaking, you go down in the same gear you came up, but early on I played it safe and sometimes used one gear lower. I've gotten much more comfortable even having to adjust which gear I'm in if need be. A lower gear that keeps your RPM's up higher definitely helps control your speed better. 

I frequent a truck drivers forum. Everyone says always go down at least one gear lower than going up. The rpm's have to be up to work better and some engines respond better than others.

 

[Buscrusher]

1 hour ago, beemergary said:

 

I frequent a truck drivers forum. Everyone says always go down at least one gear lower than going up. 

 

I've heard the same rule of thumb. Some of that has to do with modern aerodynamics of many of the newer trucks, plus much better power. I remember when 300 hp was big. Another piece of that is the weight. In RV service the weights are maybe half of a loaded commercial truck. To me the main thing that causes the most trouble is being in a hurry. 

[Jaydrvr]

As I've been doing this for about 800k miles on my current Volvo, my technique is very basic and lazy. Crest the hilltop about a gear below what I think I'll need based on my weight, set my cruise to keep the revs up and the speed down, and just let the computer do all the work. It will adjust the Jake stages as needed with virtually no driver input or service brake application. I like to keep my brakes cool and ready. YMMV Jay

[porky69]

Keep in mind that cruise control and jake brake parameters can be adjusted in the ECM. Not every truck (even if identical drivetrains) will be set the same way so far as  at what speed the jakes come on, whether or not they automatically switch between hi/med/low, if the cruise control will allow the jakes to come on, and many other parameters that affect engine braking.

 

As indicated above the higher the RPM the more braking power there is. At a given engine RPM the engine produces the same braking power whether in 1st or 10th gear, but the mechanical gear reduction of the lower gears (at the same RPM)makes the braking more effective as you gear down.

[mr. cob]

Howdy All,

When it comes to brakes, be they regular service brakes, Jakes or exhaust, you can survive going down a mountain 10,000 times going to slow, you will probably die going down it to fast once.

Dave

[Cotreker]

Hello All,

I have been reading your replies today on my phone while working.  I will try setting my cruise while going down hill and setting my brake.  Most of the time it works very well but every now and then it does not turn on.  I  had the overhead run on the motor recently.  Thanks for the comments and replies.

Dennis / Colorado

[Alie&Jim's Carrilite]

3 minutes ago, Cotreker said:

Hello All,

I have been reading your replies today on my phone while working.  I will try setting my cruise while going down hill and setting my brake.  Most of the time it works very well but every now and then it does not turn on.  I  had the overhead run on the motor recently.  Thanks for the comments and replies.

Dennis / Colorado

Try putting your foot behind the clutch pedal and lifting the pedal up.  Try engaging the cruise again.  With the Jake on and in the highest position- most aggressive, it should engage to keep the truck at the set speed the cruise is on.

[Cotreker]

Jim I cannot wait to try this idea! Many thanks.

[BlueLghtning]

12 hours ago, beemergary said:

 

I frequent a truck drivers forum. Everyone says always go down at least one gear lower than going up. The rpm's have to be up to work better and some engines respond better than others.

 

That's probably a safer idea for sure and I probably did that more times than not. I'm certainly being cautious coming down mountains with our rigs. I don't mind being the slow guy coming down. 

[SuiteSuccess]

First long trip with my truck and trailer, was traveling I40 between Ashville, NC and Knoxville, TN in a hellacious thunderstorm.  I was doing 35-40 mph, truckers complaining on CB about "rookie" holding them up.  Guess what, I made it home alive and in one piece.  Saw two trucks in the "run-off" lanes where they lost it coming down mountain.  Being a "professional" means nothing if you're stupid.

[beemergary]

2 hours ago, SuiteSuccess said:

First long trip with my truck and trailer, was traveling I40 between Ashville, NC and Knoxville, TN in a hellacious thunderstorm.  I was doing 35-40 mph, truckers complaining on CB about "rookie" holding them up.  Guess what, I made it home alive and in one piece.  Saw two trucks in the "run-off" lanes where they lost it coming down mountain.  Being a "professional" means nothing if you're stupid.

Frequent this truckers forum. Not many real truck drivers left. They call um steering wheel holds. Guys with towels on their heads and flip flops. In the tech forums guys can't even change a light bulb. Theirs lots of stupid truck driver videos out there. They really have fun with "Swift" drivers. See lots of video's on facebook of pile ups on icey highways. Its usually the big trucks that are out of control doing the crashing.

[Cotreker]

Jim, just back from a sled trip in the mountains and I did your trick by pulling up on the clutch.  This was the trick the jake worked every single time, I am so happy with my truck and now my new camper on the back!!!!!!!!!  No chains this weekend deep snow on the mountain.

Dennis

 

[Alie&Jim's Carrilite]

8 minutes ago, Cotreker said:

Jim, just back from a sled trip in the mountains and I did your trick by pulling up on the clutch.  This was the trick the jake worked every single time, I am so happy with my truck and now my new camper on the back!!!!!!!!!  No chains this weekend deep snow on the mountain.

Dennis

 

Awesome!  There may be a spring or tensioner that you may be able to adjust to help keep the pedal in its proper place.  I know a bungee cord has been suggested in the past.

[Pete Kildow]

With your weight, a Jake is just a nice thing to have. No way your brakes should ever get hot. Been off donner, 4th july, Cabbage, Elk, Grapevine. Way before I had a Jake. Grossing 50.000 lbs or less. It was a walk in the park.

Now get up around 70,000 lbs or more, it can get fun fast. 

Jake brake use for me. Start out in stage one, if it holds me fine. If not I move to stage 2. All while in a lower gear then high. If loaded heavy, and I pulled say Donner in 7th gear. I'm going down if loaded heavy in 6th gear. Rather go down slow hundreds of times. Rather than that wild ride with no brakes.. If in the right gear, third stage should hit hard. Slowing you down fast. Thus having to move to second stage or even first stage.

90% of the time 4 cylinders will be all you need. ( Second Stage on a three stage brake) Third stage is for when traffic catches you and need to slow just a little more. 

 

And Please don't only watch in front of you. Watch for that one person that is having issues with there brakes. Get out of there way, of they may well run you over. So many times you see a RV or empty truck. Hanging out in the left lane, enjoying life. When there about to kill someone. That has gotten in trouble, and can't stop. If your watching those mirrors like everyone should. You can make room for a Runaway. And I don't care how careful a Driver is. One person can throw a wrench into there perfect drive down a grade.

1986 NY state. Steep grade, and a lady back out into traffic. I lock the brakes down, as I see she has no ideal a 80,000 lb semi is about to hit her! I had been down this grade dozens of times. Always in the right gear to make it down easy. But This lady as soon as she see's me. Locked up can't move. I did not hit her, but lets say the brakes were bad hot.

Its always that if, and if this does not happen. I had no issues, also years before I got a truck with a jake on it. IF I had been that driver in the wrong gear. Moving faster then I needed to be. That lady is 99% dead, and me with her I'm sure.

Sorry for the Rambling.

 

Pete