Jake brake: Better, but how much better?

[Roamin Mike]

Ladies and Germs,
Still searching for that elusive perfect used rig. Another question has arisen. It's been brought to my attention that if I'm going to be doing much driving on grades then its a good idea to have an engine brake or exhaust brake. After some reading on the subject, I think I've determined that the engine brake is preferable. But HOW preferable? Will I be able to get by fine with just an exhaust brake even though the engine brake is better? And some EBs have two stages? What does that do? And I read something about the noise of Jake brakes - is that a big issue?
Thanks again!

[IASM]

VERY.A true engine brake provide the equivalent horsepower in braking. An exhaust brake does provide some back pressure but not the leaning forward in your seat. I have a three stage with 1 being two cylinders and 2 being three cylinders and 3 being all six. On mine the variable pitch turbo lays flat and works as a somewhat exhaust brake and also holding down noise so its barely discernible. When I am navigating mountains I keep the brake on 1 and if the rig is gaining speed I move to 2. If that's not enough I go to 3 for a few minutes then back to 2.I rarely use the service brakes while driving and rarely use 3. On mine with 3 it downshifts the transmission so the slow down is excessive. Post any other question and will be glad to help .

[jacwjames]

I have a 2002 Monaco Windsor 38 PKD. This is a heavy rig for the length and we carry a lot of "stuff". I pull a 2005 Jeep Grand Cherokee.

We have an exhaust brake. When I flip the switch it puts the transmission into 2nd gear but will only actually downshift to a safe gear, it usually drops to 4th gear as we descend a hill. Coupled with the exhaust brake the rig will usually maintain or slow down, occasionally I may have to pulse the service brake. What is key is that as I am approaching a steep grade I start slowing down before I hit the grade.

I also use the exhaust brake when exiting the highway, slowing in traffic, approaching stops etc. I use the heck out of it to save my service brakes.

[Smitty77]

Some thoughts and info:

Jake Compression Brakes provide higher braking HP then Exhaust Brakes.

2 Stage and 3 Stage Jake Compression Brakes are the norm:
-2 Stage usually are found in mid size blocks and up. In the Cummins line up, that starts with the ISL, though also many ISL's can be equipped with Exhaust Brakes instead. Stage 1 = 3 cyl of compression braking. Stage 2 = 6 cyl of compression braking.
-3 Stage Jake Compression Braking usually are found in BIG BLOCK engines (ISM/ISX, CAT 12/13/15, Detroit). And they are 1 = 2 cyl, 2 = 4 cyl and 3 = 6 cyl.

You can also find some coaches with Allison Retarder Transmissions, a nice option, such as in Foretravel's.

The interior layout and goodies is personal thing for sure. But when shopping for a coach, I usually recommend buying the highest quality coach that fits your budget. Dropping years if needed to remain within budget. I recommend getting the biggest engine you can. Quite often a BIG BLOCK engine will deliver the same or better MPG, due to loafing as it works, and quite often different gearing. But then you have the added power if needed, and the superior braking horsepower of a larger block engine.

Really consider your planned usage carefully. Make sure you have adequate CCC and Towing Capacity. I personally like TAG's due to the extra set of brakes, and usually higher CCC and towing capacity. I also like side radiators, as they are usually easier to access the engine, and usually also use less HP to run the fans.

Best of luck to you on your search,
Smitty

[ecurb74]

As to what Smitty said.......Ditto!. I have the retarder and pretty much think it's the "Cat's Pajamas". The retarder has a joy stick control on the shift pad with 6 positions. I've travelled down mountain passes and with the retarder you are pretty much in full control. If you are hunting for the "perfect coach" it's something to consider.

I also went older but higher quality and so far I'm not regretting the decision. Always put "quality" first on the list of priorities. Good luck.


Bruce & Teresa
2000 Foretravel U320 4010
Cummins ISM 450hp
Allison HD4060R 6 Spd W/Retarder

[Smitty77]

Originally Posted by ecurb74

As to what Smitty said.......Ditto!. I have the retarder and pretty much think it's the "Cat's Pajamas". The retarder has a joy stick control on the shift pad with 6 positions. I've travelled down mountain passes and with the retarder you are pretty much in full control. If you are hunting for the "perfect coach" it's something to consider.

I also went older but higher quality and so far I'm not regretting the decision. Always put "quality" first on the list of priorities. Good luck.


Bruce & Teresa
2000 Foretravel U320 4010
Cummins ISM 450hp
Allison HD4060R 6 Spd W/Retarder

That is is a sweet combo of the very mature, and much simpler era, of the ISM along with the retarder. That era coach was on our short list when shopping. My major mistake, was letting the DW see the size of the galley in the Allure. My target CC was the Intrigue, with the C12/13. Knew the Allure did not have the BIG BLOCK option... So a tip when shopping, do not let the DW into any coach that does not meet your mechanical criteria!

I did not follow the advice I so easily share today - of buying a BIG BLOCK!!! Have spend some coin on trying to improve the ISL370 CAPS era engine we have, but nothing takes the place of displacement! We have a two stage Jake Compression, and even in the medium size block, it has taken us down some pretty impressive grades without using service brakes. Sometimes need to drop it into 3rd, and on one grade, 2nd - but overall pleased with even the mid size block braking HP. Power is fine 95% of the time.

I do feel that extra reserve power capacity, is a real safety advantage. These coaches do not 'accelerate' rapidly, but reserve power can still help you get out of a problem.

Best to all,
Smitty

[skypilot_1]

After three coaches and few thousand miles in coach with IFS, 2 stage engine compression brake and disc air brakes, I was thinking of going back to a gas rig as we don't do more then 5k miles a year now. DW asked if I was nuts, and let me know it would be without her. She's a white knuckler in the mountains.
But what I enjoy most is 1250 Lbs torque.

[Mr_D]

Good info above, not much I can add.
We have the three stage engine brake, when engaged the trans preselects 3rd. I very seldom need the high position, usually low or medium is enough. And it isn't noisy at all when engaged.

[Jim_HiTek]

I have a 23,000 lb Class A without an exhaust brake and I get along fine downshifting the tranni on long grades. Then I tap the brakes here and there on the trip down depending on steepness and length of the downhill.

There have been times when I wished I had an auxiliary brake system on very steep and long hills, because I have to interact with downshifting/braking as I descend, but that's probably just laziness. My equipment handles downhills just fine as is without having to worry about something else to repair or maintain.

Put another way, I would not refuse a bargain RV even if there wasn't an exhaust braking system.

[ecurb74]

Originally Posted by Jim_HiTek

Put another way, I would not refuse a bargain RV even if there wasn't an exhaust braking system.

Very true! I wouldn't turn down a nice coach just because it only had an exhaust brake. With a little common sense you can get about anything to the bottom of the hill. But on the other hand I've met some folk that have never been introduced to common sense! Had a good friend, book smart, but couldn't put a wood screw in a 2X4 without cross threading it! Bless his heart!


Bruce & Teresa
2000 Foretravel U320 4010
Cummins ISM 450hp
Allison HD4060R 6 Spd W/Retarder

[twojayhawks]

Good post. Most are focused on HP only and as others have said all RV's will make it to the top....on their own time table. But there is another kind of pucker that happens when you are not confident you can control your equipment going down a long steep grade.

[slickest1]

An exhaust brake was designed for medium duty trucks and will work well in a Motorhome.

Engine brakes were designed more for the heavy duty trucks and the weight ratio they are holding back.
As you get into the larger coaches and bigger power you can get the engine brake. In a sense they are a little overkill but it never hurt anything to have more stopping power.

I have an ISC 350 with an exhaust brake and it works well. I only wish it had the full engine brake.

[Papa_Jim]

I've driven our coach with and without the exhaust brake. The exhaust brake does help, but I wouldn't want to totally rely on it to control the speed going down a really steep grade.

Jim

[YC1]

My 400 ISL has a variable ratio turbo and exhaust brake. It works well to slow my heavy rig and toad. I still have to use the service brakes on a steep grade but it works just fine overall. I would not have it be a deal breaker.