Community Forums

jimbo2013 · 12-09-2013, 04:40 PM

Never had one so not sure to use on flat regular roads or just hills or heavy traffic.

If using it is just turn on and kicks in when I hit the brakes?

Sorry for what is a basic ? to most here

Alan Wilson · 12-09-2013, 04:51 PM

I am learning this myself and from what I can tell you have to use it a few times to get the hang of when to turn it on. I just let off the throttle and it appears to do the rest. I was told not to drive with the PAC break on but then a lot of this us new to me as well. I will be watching the responses you get to see if I am clueless or not.

Alan

Steve Ownby · 12-09-2013, 05:01 PM

You will find many opinions on this subject. Personally, I use mine all the time. Slick road surfaces are the only real prohibition. The primary function of the Jake/compression/exhaust brake is to control your speed of descent on down grades. They can generally take some of the burden off the service brakes in most other situations. The main thing is to turn that sucker on and start learning how it works.

There are a number of ways that the ECM can be programmed to activate the brake. The most common is when you let the throttle close completely, the transmission selects a lower gear (generally 2nd or 3rd) and the brake activates. It stays on until your speed is under 10 mph or you open the throttle. There may be some variation but this is the basic operation.

thrushl · 12-09-2013, 05:04 PM

Quote:

Originally Posted by jimbo2013

Never had one so not sure to use on flat regular roads or just hills or heavy traffic.

If using it is just turn on and kicks in when I hit the brakes?

Sorry for what is a basic ? to most here

If you have a JAKE BRAKE, then the answer is actually quite simple. EVERY time you need to slow down or stop. I ride with one hand on the wheel, right foot on the gas, and left hand on the Jake switch. I normally only need to use the service brakes on very steep hills or to actually stop the rig at a stop light/sign/etc.

These REALLY save your service brakes. When I was doing my CDL training I was taught that the service brake was ONLY for total stops. I'm not that good, but pretty close.

You'll learn to love it.... Best part of a DP, I think...

slemnah · 12-09-2013, 06:25 PM

I do not like the way it drives if I leave it on all the time. I also put it on when I need to stop and then turn it off when get going again. I also hardly use my brakes. You will also have at least a high and low Jake. Low will use three cylinders to slow you down and high uses all six based upon how fast you want to stop. If I am in stop and go traffic I will leave it on and put it in low to assist in slowing down. If I am coming down the backside of a mountain I will leave it on high unless I am loosing too much speed. Once you get used to it you will love having it.
Steve

KSCRUDE · 12-09-2013, 06:44 PM

The best way to use a jake is to leave it on high all the time and control it with you right foot. When you get off the gas the jake comes on. Slowing down to fast just push on the throttle a little and jake turns off and you can still coast. Need more braking just let off the throttle again. Now going down a long grade you can us the low, med, high switch to adjust your speed with you foot off the gas as you descent the grade. We never turn the jake off on the semi trucks as they are there to save the service brakes. Our service brakes last forever, almost. When I started trucking we didn't even have jake brakes. They are one of the best things to ever be put on a truck, for safety and brake longivity.

Automatic slack adjusters are another great thing we all have now, but nobody used to have.

Mac99 · 12-09-2013, 07:10 PM

I had my Cummins re-programmed so that the exhaust brake comes
on when I touch the brake pedal. It used to come on whenever I let
off the throttle pedal. I did not like this, as I could not coast. I now
leave it on all the time, except that once in a blue moon I may turn
it off for a momentary brake application.
When the stuff hits the fan, you will not have time to turn it on, it
needs to be on all the time. IMHO.

Ray,IN · 12-09-2013, 07:15 PM

The term Jake Brake is a generic term. I suspect your 2000 has an exhaust brake.

You've received two entirely different replies, three for an engine retarder brake and one for an exhaust brake. Most MH's have an exhaust brake, some an engine retarder brake. Each operates entirely different. The exhaust brake closes a valve inside the exhaust pipe, the engine retarder brake changes valve timing and turns the engine into an air compressor-in reverse. This is the best of the two types.

From reading many posts/threads I reached the conclusion most of the exhaust manifold cracking may be caused by continual use of the exhaust brake overheating the manifold metal.
The coach mfgr, chassis mfgr, and engine mfgr, do not recommend continual use of an exhaust brake.
Service brake wear. Spartan chassis says their service brakes are designed to last 200,000 miles, and infrequent use will cause them to glaze.
That said, I lay my left hand on my knee, very near the activation switch, and a quick jab with my hand activates the ebrake circuit when it's needed. Examples are; quick deceleration at off-ramp, and long downgrades.

slemnah · 12-09-2013, 07:21 PM

Jumbo, what make, model and year is your motorhome and what engine do you have? Not every Jake brake has a foot pedal, mine only has a switch.

thrushl · 12-09-2013, 07:23 PM

Quote:

Originally Posted by macadnphyl

I had my Cummins re-programmed so that the exhaust brake comes
on when I touch the brake pedal. It used to come on whenever I let
off the throttle pedal. I did not like this, as I could not coast. I now
leave it on all the time, except that once in a blue moon I may turn
it off for a momentary brake application.
When the stuff hits the fan, you will not have time to turn it on, it
needs to be on all the time. IMHO.

Valid point good Sir

jimbo2013 · 12-09-2013, 07:36 PM

THe data sheet from Monaco says its a retarder brake.

I only saw a switch, no pedal

I'm going to spend tomorrow going thru it all before a 120 mile trip home Tuesday or Wednesday.

When I demo'd it last Friday I didn't use the Jake, just wanted to keep it simple.

It's a 2000 38 HR Endeavor with a 330 HP - 3126

Steve Ownby · 12-09-2013, 08:56 PM

Quote:

Originally Posted by jimbo2013

THe data sheet from Monaco says its a retarder brake. I only saw a switch, no pedal I'm going to spend tomorrow going thru it all before a 120 mile trip home Tuesday or Wednesday. When I demo'd it last Friday I didn't use the Jake, just wanted to keep it simple. It's a 2000 38 HR Endeavor with a 330 HP - 3126

You have an exhaust brake aka PAC brake which is one major brand. It only has an on/off switch. When you start home turn the switch on & start the learning process.