Jake brake not working on high

And while the 6.7L exhaust brake won't bring you to stop. It does a great job of holding your speed down a grade. I don't use my EB to SLOW me down, But rather to HOLD my speed. I cross the summit on a 7% or 8% grade, slow down about 5 mph slower than I want to travel down the grade and set the EB.

Jake brake not working on high. A brake system is one of the most important parts of a vehicle. No matter what kind of vehicle people use, an efficient braking system will always be of utmost concern to ensure sa...

Jake brake on ‘97 kenworth w900 not engaging fully in high. Low and medium work as usual but high setting runs more like the medium and sputters out. Good afternoon and welcome to JustAnswer! I'm Nick and I'll be helping you out today. Please give me a few minutes to review your question and I'll be right back.

Jake suggests the brake be rebuilt at 150,000 miles. The overhaul kit p# 4559-31180 updates the Jake to current revision level and includes reset screws, springs, control valves, most of the snap rings, and solenoid o-rings. The exhaust valve yoke adjusting screws need to be checked for wear.If the Jake brake on your 2004 Freightliner Columbia 120 with a Detroit Series 60 14L DDEC V engine is not working, there could be several possible reasons for this issue. Here are some common troubleshooting steps you can take:Check the Jake brake switch: Make sure that the Jake brake switch is functioning properly.Removed valve covers, Cyliders 3-4 jakes work on low. Cylinder 1-2 and 5-6 work on medium. On high only banks 1-2 and 5-7 work. The middle bank does not compress the Jake slave pistons. Used scanner and ecm recognizes low medium and high brake position.Things You Should Know. A Jake brake increases braking speed by turning your truck’s engine into an air compressor, which pushes on the pistons to slow …Jake Brakes: Do They Harm the Engine? Jake brakes do not affect the engine when utilized properly. Drivers should check their oil before starting their trip to make sure it is not low. When oil levels are low, using an engine brake can harm the engine. Additionally, truck drivers should wait until the engine has warmed up before applying the ...Low/High retarder current low indicates an open circuit for the Jake on cylinders 3 and 4. Most often when you have both these codes, it is an indication of a problem in the harness under the valve cover or the harness on the outside. Not often is multiple codes a Jake solenoid problem. Please reply back if you need more help or have more ...Supplying a ground enables the Jake brake for Cylinders 3, 4, 5, and 6. Low Jake request (pin K3) Supplying a ground enables the Jake brake for Cylinders 1 and 2. Park Brake (pin H2 on the ECM) Has no effect on Jake functions. Service Brake (pin G2 on the ECM) Has no effect unless Jakes are programmed to only come on with service brake. ThrottleRe: Jake brake in ATS. #2 by Max » 18 Nov 2022 00:33. every engine in game has engine brake. only the newer or europe-based engines might have bit different setting. if you take transmission without retarder it wont affect the engine brake functionality in any way. control style is also independent on both engine and transmission.

Engine braking works by using the vacuum created by the driver releasing the accelerator pedal to restrict airflow from the engine's cylinders. This decreases the engine's energy output, causing resistance in the engine and braking force. The benefits of engine braking include reduced brake wear, better vehicle control, and improved fuel ...Typical engine brake solenoid related brake performance symptoms would be: Front solenoid EPA07/ EPA10/GHG14 - Loss of low engine braking. Rear solenoid EPA07 - Loss of medium engine braking and high will be the same as low. Rear solenoid EPA10/GHG14 - Medium engine braking feels like low and high will be slightly better than low due to EGR flow.Experienced RVers will mention that Jakes will provide greater braking over a wider range of engine RPMs - that's because an exhaust, or Pac, brake gives more braking effect when the engine is turning over faster, and less as RPMs head downhill. That may be a moot point if you have a motorhome without any engine braking system, because once ...My boyfriend has a 2015 Peterbilt 389. 2000s Detroit 60's series 12.7L. He is having issues with his Jake brake and cruise control. They work, then quite working, but they work and quite working at the same time.When I use the brakes with the Jake brake on and on high I see no results, even after down shifting to 4th. Do I have a problem other than mental? ... You can test to see if the jake is working by simply starting the engine from the drivers seat with the toll window open, increasing the rpm's with the transmission in neutral, then releasing the ...

The power then goes back to the cab switch for the high and low selection, then to the solenoids. That should be clear as mud. Power to the Jake switch can be off a relay that goes bad and a type 2 resets every time the power goes off. You want to test with a volt meter to check for poor connections.As long as I didn't let the speed get too high on the grade the Jake has worked great. I have been able to keep the coach at 60 to 65 mph with only the occasional touch of the service brakes. ... 92 DDA engines using the Jake Brake, while they do work, they are not nearly as effective as the retarder (Allison) and for best effect, you need it ...2004 Cat C15 in a Peterbilt 378, VIN. 1NPFXBEX34D830549. Jake brake is not working. Checking for voltage at the power supply to the Jake on off switch with a power probe, key on engine off, it shows 1 … read moreThe Jacobs' Engine Brake, or Jake Brake, is an essential component in slowing and controlling your vehicle. By using the superior retarding capabilities of ...It won't work on a T680. When you have the engine brakes turned on, it's activated by tapping the brakes, and it'll work only down to about 1100 RPM. Once it gets below that, it'll automatically cut out. The engine brake will only work down to seventh gear on a 10-speed. I have not seen it work in sixth or below.In order to troubleshoot a 2533-5 or 1072-5 diagnostic code, use the "Compression Brake Low/High Override" on Cat ET. In order to troubleshoot a 2535-5 or 1073-5 diagnostic code, use the "Compression Brake Med/High Override" on Cat ET. A. Turn the keyswitch to the OFF position. B. Disconnect the harness at the valve cover connector.

Overwatch shop unavailable.

Ask Your Own Medium and Heavy Trucks Question. Nothing in high. Technician: Nich M. That's odd, sounds like a truck side wiring issue. So in low the center jakes are turned on. In medium the front and rear jakes are turned on. In high both the low and the high are turned on (now all 3 brake housings). High is basically low and medium together.401 Answers. Posted on May 29, 2010. SOURCE: where is the oil pressure sensor located on a 60. 60 series detroit has oil sender on driver side near rear of engine just above the starter. It usually has 3 wires, and sometimes can be buried in the harness, so you may have to look under wiring harnesses in that area to find.Feb 14, 2010. Jacksonville, FL. 0. On the dash it should light up "engine brake" in yellow letters. To activate the engine brake you'll need to turn it on and then press the brake pedal. If you dont press the brake pedal then nothing will happen. I do believe there may be something wrong with your truck through.Austin. Posted 7/1/2016 09:27 (#5385186) Subject: Cat C15 jake brake question. Garrett County, MD. So this might be a long post but if you know about jakes on cat engines I could really use your help. One of our trucks is an International 9400 2002 model I believe. Has a cat c15 6NZ in it. When we bought it a few years ago the previous owner ...Use a gear that is low enough to allow the jake to do 90% of the braking when descending a steep slope. To safeguard the motor, run the Jake in the shifting range, around 1100-1400 RPMs. It's dangerous to use it when shifting; it might cause your truck to stall.

Location: Wimberley Texas. Posts: 20. Jake Brake Won't work. 2003 Monaco exec. Cummins ISM 500 with 2 stage Jake Brake. It started working intermittently awhile back. It then got to the point that when you applied the jake brake pedal the only way it would work was when you toggled the switch from low to high. I took it to Cummins and they said ...The Jake Brake is an invaluable, extra tool available for truck drivers. It is primarily used for slowing down a big rig in certain situations. It is not intended as a substitute for the service brakes. It operates using the diesel engine’s own power. The same force that gives the truck power is used to slow it down.Message format. Flat Threaded Nested. Putz. Posted 2/20/2013 21:38 (#2914007) Subject: Jake Brake ? on Detroit 12.7. NW ND. I've got a 2002 Freightliner with 12.7 Detroit. Last fall I noticed that sometimes the Jake would not engage when I flipped the switch. Now it hasn't worked at all for the last few days.If it is working right, low (one Jake) will give you the Cummins death rattle just before it disengages as you come to a stop. High (both Jakes) does not produce the death rattle before it disengages. High has a more aggressive braking action especially at highway speed. At low speed it is not as noticeable of a difference.By releasing the compressed air, the Jake Brake reduces the amount of work the engine has to do to slow down the vehicle. This method of braking not only helps to preserve the lifespan of the service brakes but also offers greater control over the vehicle's speed, especially in downhill or high-speed situations. ... especially in downhill or ...These compression brakes hold pressure in the cylinder then releases it in an explosive, very noisy manner. That's why so many communities have ordinances against Jake Brakes. An exhaust brake, mounted just after the turbo, is usually a butterfly valve that is turned by a lever to partially block the exhaust gasses.Austin. Posted 7/1/2016 09:27 (#5385186) Subject: Cat C15 jake brake question. Garrett County, MD. So this might be a long post but if you know about jakes on cat engines I could really use your help. One of our trucks is an International 9400 2002 model I believe. Has a cat c15 6NZ in it. When we bought it a few years ago the previous owner ...My Jake's has low medium and high setting. My middle jake brake won't turn on at all and high doesn't work to well I believe that's tied into the medium setting not working. I installed a new switch and put both jake brake solenoids. Still no Luck. Any suggestions. Dd13 2011 cascadia. Click to expand... I don’t know Detroit’s but I’m ... We would like to show you a description here but the site won’t allow us.

Use a gear that is low enough to allow the jake to do 90% of the braking when descending a steep slope. To safeguard the motor, run the Jake in the shifting range, around 1100-1400 RPMs. It's dangerous to use it when shifting; it might cause your truck to stall.

BLACKBEAR. 312 posts · Joined 2008. #9 · Jul 19, 2008. When I first start the truck if the temp is down around 40. I pull my jake brake on to help warm up faster. The temp will only go up about 300 dreg more. I have never had my temp get to high when braking with the jake..Go for it--- BEN.The cost of running a truck is of high importance to the truck owner. Longer lasting brake material is a selling point. Jake brakes do nothing to improve CO2 emissions, and add weight the engine and would not be seen as an improvement to a buyer. They are not a priority to the car engineer. Jake brakes are very noisy.keep stroking. I'm working on a 2004 Cat MBN C15. The jake brake has always given the driver trouble. After closer inspection of the assemblies, I found one of them cracked. It has the Pac Brake brand on it. For some odd reason I was told that only the MBN engines used this particular jake brake assembly.The engine brake on our 2001 freightliner with pre egr Detroit 60 series has been weal since day one. ... before its put back together have the jake spools rebuilt. The part where not all cylinders are hitting sounds like electrical at the jake head itself, more than likely one of the spool wires came off, the tech should watch for this on ...I have a brand new Pete, the Jake's stopped working at 60k miles. Turns out all the bridges broke on my heads and the valves weren't re-routing the exhaust properly. Glad it's still under warranty because the entire top-end had to be replacedIf your really heavy you can roll down hill in stage 3. If the RPMs hit 2250 apply a little brake pressure to slow down. Don't turn off the engine brake because then it will go into neutral. If it's to much engine brake and truck is slowing down to 1,800 RPMs. Switch to stage 2 and let it roll back up to 2,200 then turn stage 3 back on.Jan 21, 2019 · Posts: 131. HELP: Cummins N14/Allison Jake Brake Issue. Over the last month or so, I've noticed my Jake Brake working intermittently. Today, it nearly became a major issue that could have harmed my family. We live in Arizona and took the kids to a soccer tournament. I was traveling through Salt River Canyon (20 miles of 6-8% grade). On your steering wheel, press the engine brake button. This will also light up the engine brake icon on your left dashboard and the buttons on your right. Step 2. Select the level you need from the button on your right: high, medium, or low. Step 3. Slowly release pressure while stepping off of the accelerator.This fault code indicates that the Jake Brake Stage 2 circuit failed open. 83.2.1 Open Circuit Check Check as follows: 1. Check for multiple codes. [a] If SPN 1073/5 and SPN 2791/5 are active repair the open between the pin 62 of the 120-pin MCM connector and the front Jake Brake and fan control solenoids. [b] If only SPN 1073/5 is active, go ...1 - When you tap the brake, it takes 6-10 seconds before the engine brake engages. 2 - When descending a hill, with the engine brake engaged, once the truck goes faster than 67mph, the engine brake turns itself off. As the truck slows back down (on it's own or by increased pressure on the service brake), when you get below 67mph, the engine ...

Horchata strain thc level.

How to run commit madden 24.

A Jake Brake, also known as Jacobs Engine Brake, is a vital supplementary engine braking system primarily utilized in heavy-duty diesel trucks and commercial vehicles. This innovative technology plays a critical role in slowing down and managing the speed of these substantial vehicles, especially when navigating downhill gradients or steep ...1 - When you tap the brake, it takes 6-10 seconds before the engine brake engages. 2 - When descending a hill, with the engine brake engaged, once the truck goes faster than 67mph, the engine brake turns itself off. As the truck slows back down (on it's own or by increased pressure on the service brake), when you get below 67mph, the engine ...Feb 17, 2012. S.E. WY. 0. Two questions about engine brakes here.. The first, on a 2004 Freightliner Columbia with Detroit series 60, 10 spd Eaton Fuller, the engine brakes work in 10th, 9th, 8th, and sometimes 7th (if you don't press the accelerator too much when getting the rpm's up) -- they don't work at all from 6th on down. The second ...Jan 8, 2015 · These compression brakes hold pressure in the cylinder then releases it in an explosive, very noisy manner. That's why so many communities have ordinances against Jake Brakes. An exhaust brake, mounted just after the turbo, is usually a butterfly valve that is turned by a lever to partially block the exhaust gasses. The higher the brake setting, the greater the braking power, use lower settings in less-than-optimal road conditions. Engine should be at operating temperature and oil should not …Things You Should Know. A Jake brake increases braking speed by turning your truck’s engine into an air compressor, which pushes on the pistons to slow …4276 posts · Joined 2007. #7 · Jul 4, 2011. No, a Jacobs brake (compression brake) only opens one exhaust valve. If you look in the pic, the red circle shows the valve that releases compression when the brake is activated. AThe one in blue is the other exhaust valve and is only used during normal operation.6.7 exhaust brake problems. Ok guys I have a 07.5 6.7 with 150,000 miles on it. I have the egr/cooler delete, and the dpf delete, and running the XRT. When I decel on a hill the EB with pulsate when around 2100 rpm, it comes on strong them backs off, comes on strong then backs off, when it gets down to about 1600 or so it settles down.The switch on the dash selects between high (all 6 cylinders) or low (only 3 cylinders). The foot switch actually activates the Jake engine brake on and off, as long as no throttle input is registered. On my 02 Exec the switch to left of driver is for 2 stage Jake, lo-hi not on/off. Thanks guys! ….

When is the engine brake most effective? At high RPMs with the transmission in a low gear ... The Jake Brake actually limits the amount of exhaust that can flow out of the engine. ... its mostly used 6 thru 10 gear, 25 to 65 mph, at 1300 to 1800 rpm. And works better the higher the RPM but will work on my truck from 1300 to 1800. Woody's ...We would like to show you a description here but the site won't allow us.6.7 Engine Brake Issues. I just have a few questions. Looked around but didn't see anything related to my exact issue.. So my turbo engine brake is not working on a consistent basis. Sometimes when I got the button on the engine brake works, and other times it doesn't. The conditions seem to be the same all the time I'm at highway speeds.Volvo VNL jake brake don't work Discussion in 'Ask An Owner Operator' started by Schöne, Nov 10, 2021. Nov 10, 2021 #1. Schöne Bobtail Member. 47 20. Feb 23, 2019 ... I drove with out Jake's in the mountains, I was in 6th gear. It sucked. Brake pedal switch went out or maybe it was the clutch switch. 77fib77, Nov 10, 2021. 77fib77, Nov 10 ...Dec 7, 2006 · 11-22-2006, 09:29 PM. Ben, Engine brakes (Jake brakes) stop working 8 out of 10 times because of electrical connection issues, the other 2 times it's mechanical and expensive to fix. : (. Jon knows the Prevost scheme and will send you in the right direction. Jake brake on ‘97 kenworth w900 not engaging fully in high. Low and medium work as usual but high setting runs more like the medium and sputters out. Good afternoon and welcome to JustAnswer! I'm Nick and I'll be helping you out today. Please give me a few minutes to review your question and I'll be right back.Im working on a 2010 volvo d16. Driver said she was pulling into a truck stop and push in the clutch and she herd a loud pop. now the cluctch is stiff has trouble going into gear, no jake brakes and no cruise control. they are not in the yard yet so i kinda wana have an idea on where to look.Subject: Jake brake problem on Cummins ISX. NE, KS. I have an 07 KW (950,000) with a cummins ISX and the Jake brake has stopped working properly, we have already dumped a bunch of money into it and not fixed a thing. The problem is when we leave the yard the Jake will work fine for 15 miles and then it acts like the final stage …keep stroking. I'm working on a 2004 Cat MBN C15. The jake brake has always given the driver trouble. After closer inspection of the assemblies, I found one of them cracked. It has the Pac Brake brand on it. For some odd reason I was told that only the MBN engines used this particular jake brake assembly.The Jake Brake is an invaluable, extra tool available for truck drivers. It is primarily used for slowing down a big rig in certain situations. It is not intended as a substitute for the service brakes. It operates using the diesel engine’s own power. The same force that gives the truck power is used to slow it down. Jake brake not working on high, There should be a tag on the valve cover. It could start with 4CK, 8TC, or 5EK. I mainly need to know if this is a 3406 PEEC engine or a 3406E. A PEEC engine is half electronic and half mechanical. If it is a PEEC, ir will have a pump and external fuel lines. If it is a 3406E, it will not have a pump and external fuel lines., Jake Brake. 768 likes · 33 talking about this. Jake Brake is an Oklahoma cover band supplying a wide range of genres., I have a cat 3406b and the jake brakes are not working they are getting 12v from the switch and the actuators are moving when powered but the jakes are not working any ideas. Submitted ... inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent. Tory Johnson, GMA Workplace Contributor, discusses work-from ..., We did not find results for: jake brake not working on high. Check spelling or type a new query. Related searches jake brake not working on high. jake brake not working on high performance:, 5. Measure the resistance across the Jake Brake solenoid. [a] If the resistance is greater than 15 Ω, replace the Jake Brake solenoid. Refer to section 82.2.1.1. [b] If the resistance is less than 15 Ω, repair the open between pins 7 and 8 of the front injector valve cover harness connector and the Jake Brake solenoid. Refer to section 82.2.1.1., Oct 10, 2013. 0. I have a 2006 379 Peter. It has 1157834 miles on a C15 Acert motor. About 2.5 months ago, my jakes seem like they are only half there. They make the sound but holding the truck or slowing it down, not so much. I found that the top of my wiring harness had been rubbed through partially by the AC lines across top of motor., Problem 3: Inspect the Wiring System. Burnt or cut with the wires can make your exhaust brake not work. So ensure you have checked the wires and find them perfect. Checking the wires is simple; remove the fuse box and inspect the wires on the back. Check the entire wires from start to end and ensure no wires are damaged or burnt., I have a brand new Pete, the Jake's stopped working at 60k miles. Turns out all the bridges broke on my heads and the valves weren't re-routing the exhaust properly. Glad it's still under warranty because the entire top-end had to be replaced, Rating: 6/10 I was on edge all day following a noon press screening of Michael Bay’s Ambulance — the new adrenaline-fueled movie starring Jake Gyllenhaal, Yahya Abdul-Mateen II and..., Nov 2, 2016 · The multimeter model I use to troubleshoot listed on the Amazon Affiliate Link listed right here: https://www.amazon.com/gp/product/B0002YFD1K/ref=as_li_tl?... , Technician: Daniel Wilson. There is also a compression brake utilizing throttle valves actuated by oil pressure. Click this link and go to PDF file page 25 for the operation.Engine brakeNot on the MBE4000. the link I posted will explain its operation. It is completely different than the Jacobs braking system on other engines., The cost of running a truck is of high importance to the truck owner. Longer lasting brake material is a selling point. Jake brakes do nothing to improve CO2 emissions, and add weight the engine and would not be seen as an improvement to a buyer. They are not a priority to the car engineer. Jake brakes are very noisy., In today’s digital age, technology has become an integral part of our daily lives. It has revolutionized the way we communicate, work, and even how we access information. One area ..., Posts: 131. HELP: Cummins N14/Allison Jake Brake Issue. Over the last month or so, I've noticed my Jake Brake working intermittently. Today, it nearly became a major issue that could have harmed my family. We live in Arizona and took the kids to a soccer tournament. I was traveling through Salt River Canyon (20 miles of 6-8% grade)., the high and low switch produces the same amount of braking. The trans downshifts to 4th then stop downshifting. That cause me to use the brakes to slow the coach. This is my first coach with a jake. previuos coaches were Cat engines with exhaust brakes. I think they should act similar.??, The higher the brake setting, the greater the braking power, use lower settings in less-than-optimal road conditions. Engine should be at operating temperature and oil should not …, Now accepting support and donation to my channel. accepting: personal check, business check, money orders, gift cards, gifts, tools, shop articles, etc,.. ..., 160 posts · Joined 2012. #10 · Dec 28, 2012. Jacobs brake is a brand name like Pac brake and the BD stuff. The two common means of supplemental braking for a diesel engine are the exhaust brake (as stated above, and of which there are a number of manufacturers) and a compression brake. People often use the term "Jake brake" for either of them., A semi truck's Jake Brake works to reduce its speed. It is most commonly used by truck drivers, who can take advantage of this feature on highway off-ramps and downhill grades. To engage the Jake brake, the driver must detach the gas from the engine and flip a switch on the engine. Many modern manual gear shifts include this switch., keep stroking. I'm working on a 2004 Cat MBN C15. The jake brake has always given the driver trouble. After closer inspection of the assemblies, I found one of them cracked. It has the Pac Brake brand on it. For some odd reason I was told that only the MBN engines used this particular jake brake assembly., The Jake Brake is an invaluable, extra tool available for truck drivers. It is primarily used for slowing down a big rig in certain situations. It is not intended as a substitute for the service brakes. It operates using the diesel engine's own power. The same force that gives the truck power is used to slow it down., In on, the cruise would not work but the Jake brake would engage anytime you let off of the throttle, regardless of if you had actuated the service brake. ... just High/Low switch). With cruise working and I step on the Jake peddle the cruise disengages but does not turn it off. When done braking all I do is hit the resume on the Smart Wheel ..., These compression brakes hold pressure in the cylinder then releases it in an explosive, very noisy manner. That's why so many communities have ordinances against Jake Brakes. An exhaust brake, mounted just after the turbo, is usually a butterfly valve that is turned by a lever to partially block the exhaust gasses., 3406B jake brakes Discussion in 'Heavy ... the switch beside doesn't seem to change, whether it's, "up" or "down". Jakes are working but,.....on which setting is the question. mile marker 27, Jul 29 ... The top spade is "power" the right side spade is "low" and left is "high". When I tested the voltage at the spade ..., Re: Jake Brake not working. #2 by natvander » 25 Feb 2017 23:02. My first suggestion would be to add a (very small) dead zone in your pedals and see if that works. It could be that the game isn't detecting that your accelerator is off. Never argue with idiots. They bring you down to their level and beat you with experience. TruckerKid. Posts: 821., Toggle the switch between high and low. There is a distinct difference in the exhaust sound between high and low. From past experiance i know that if the gas pedal is not showing 0 input the jake brake will not operate. Found a worn bracket one time on an older rv we used to own., Jan 8, 2015 · These compression brakes hold pressure in the cylinder then releases it in an explosive, very noisy manner. That's why so many communities have ordinances against Jake Brakes. An exhaust brake, mounted just after the turbo, is usually a butterfly valve that is turned by a lever to partially block the exhaust gasses. , With this script added to your server, whenever a player’s vehicle is stationary, the brake lights will be activated, unless the handbrake button is pressed. As of version 1.0.2, the brake lights are now synced across all clients. Download wk_brakelights-102.zip (2.0 KB) wk_brakelights-101.zip (1.7 KB) brakelights-100.rar (727 Bytes) …, Apr 30, 2015. 0. I have a 2005 w900 with a c15, my jake works when it is cold outside, when it starts warming up around 45 degrees it will work intermittently, if I sit with the heat running it will not work till I start driving to get cold air flowing, above 60 not working at all along with the cruise. Cat and Kenworth can not find the problem., Seriously. Not using engine brakes doesn't make you safer, having a problem using them is a warning that you may be in a hazardous situation and should consider using chains or taking a break until conditions improve. Test brake often to make sure you're not losing control and can still stop, but FFS, don't brake abruptly or stop in a lane of ..., A Jake Brake is a safety device intended to complement the service brakes. That means the driver ideally would know how to safely operate the apparatus even if the Jake Brake was not working, or had failed. Any competent operator would instantly know if the Jake is not working. The noise and the feel are pretty obvious., I have 2004 freightliner columbia, intermittingly jake brake do not work. ... Have 91 379 w/ detroit ddec ll cruise will control high idle - but NOT road speed- have been to pete dealer twice- tune of $1500.oo- replace parking brake air switch. all wires and switches appear to ..., Jake Brakes come to the rescue by providing supplementary braking power. The compression release mechanism slows down the engine’s RPM and effectively retards the vehicle’s speed. This enhanced control ensures safer descents, prevents brake overheating, and reduces the risk of accidents due to brake fade.