Does anyone have a jake brake on their 3126E Cat truck engine.I'm debating how effective it will be and most importantly-can this engine stand up to constant de-compressing being it's not real heavy duty.
Your SOL no JAKE heads available for the C-7 Cat your only choice is the exhaust brake your second choice is a telma brake which is a electromagnetic brake runs off of the driveshaft.
Ford LT 9000---I already know Cat makes an exhaust/Jake brake as I have a $1K quote for parts only--I'm just asking if anyone out there has one,performance,longevity of engine,etc.
As far as I know there is no engine brake for the 3126. Jacobs does make an exhaust brake for the 3126 but the engine won't be "decompressing" it'll just be working against a whole bunch of back pressure. So, it's much better than nothing, but not as good (as in -won't develop as much braking hp) as a engine (compression) brake and I've never heard that either type was hard on an engine. But maybe I'm wrong - anybody ever heard that a Jake is tough on engines? It's just dumping the compression at the top of the stroke, it would seem that the big bang from the fuel going off would be a lot more stress...
That would be my feeling too, Orchard. A true engine brake should put less stress on the engine by releasing the compression. The only bad thing I've heard about exhaust brakes is they can possibly make the turbo shaft seals fail prematurely. I've got no first hand experience though.
Jake brakes are hard on driveline but for a truck with a engine that doesn't have a JAKE the Telma brake is the best way to add to the braking power. Its expensive but it will hold back your truck like you wouldn't beleive some trucks it works so well you don't need to use your truck brakes. One of the local disposal company has a single axle garbage truck with a 38,000lb gvw you flip the telma on it darn near locks up the drive wheels. The volunteer firedept has telma's on all their trucks they have problems with the brake drums rusting because they use the service brakes so little. Exhaust brakes are pretty feeble.
It sounds as though the Telma system would be even more abusive to the driveline than the Jake. I agree an engine brake is more effective than an exhaust brake, but any auxillary brake system is better than none. I tested an exhaust brake in my truck and on an extended downgrade I recorded a 20 mph difference with the exhaust brake on.
Thanks guys for the input,but I really need to hear it from an owner of a Jake brake on a 3126 for first-hand knowledge.That Telma brake might be good but I think only municipalities can afford a $8K price tag.
We have Pak-brakes on about 20 3126/C7's. Don't waste your money, unless that is all you can afford. It's better than nothing, but it doesn't work that good. We've had problems with with the actuator sticking closed during acceleration. Also, ours are interfaced with tranny so that it downshifts as soon as foot comes off go pedal. Some of our heavier trucks have Telma's. They work better, but not quite worth the $9k+ they cost.
Are the trucks in everyday use or do they sit some? Have you tried the hightemp lube that PacBrake says to use on the actuators? Just asking cause I have a PacBrake on my truck and I'm wondering what to expect maintenance wise.
They are fire apparatus and ambulances. They don't sit at all. I think the main reason that the actuators are sticking is that some crews won't use them.
The local volunteer firedept has two single axle fire trucks with ISC Cummins both of them have had their exhaust brake replaced a couple times. Also one ot the local utility company runs a pac brake on their truck they have had nothing but problems with it. With the fire trucks they have telma's so they rarely use the exhaust brake. A exhaust brake really does nothing its like shoving a potatoe up the exhaust pipe. I don't know why Jacobs hasn't designed a JAKE brake for the C-7 and 8.3 Cummins because its the only engines for 5 ton medium duty trucks.
I've got an exhaust brake on my 8.3 cummins and I've had a few problems with it, but I wouldn't give it up. If the engine rpm is up, I find it's pretty affective at holding my ground speed when going down a lot of hills around here.
I only have a whopping 2 days with the pacbrake on my 8.3 ISC but it does seem to be better than nothing for sure. Like DK says - I already noticed that you have to keep the revs up to make it effective. The pacbrake manual is real clear that it needs to be used all the time or it can stick too. I'll keep my fingers crossed.
A Jake is like that too.They really work the best at,or slightly above,the Gov. top speed.Engines with 2100rpm gov. speed might say that the Jake can be used up to 2300rpm. The older Cats(3406 B's for sure)didn't have a great Jake.They'de make some noise,but just didn't have the power that the Cummins Jakes did. I drove motor coach for a short time,and one of the buses had a L10 with an auto.I'm not sure if it was an Allison,or not.But it did have a variable switch that when applied would slow the bus down FAST.It worked through the transmission somehow,and would heat the tranny fluid up to a dangerous level within a mile or two,if applied to much.(a fluid temp gauge was part of the system)But boy was it powerful. I've never seen another vehicle with that type of brake though.That worked through altering the transmissions fluid flow.Maybe it was a poor idea,and they quit using it??
The old Big Cam Cummins have a good Jake they also have a good bark to them. The older Fords with Big cam 400s have a bad habit of a Jake stall when your shifting it happened to me. You can't burp shift those trucks. The L-10 Cummins have the highest pitch Jake its hard to describe its louder than a 2 stroke Detroit like a 92 series. Cat uses a retarder it is oil operated it holds back pretty good I don't think its cheap to repair thou.
Still waiting SOOOO--Interesting reading,but again does anyone have an actual exhaust brake on their 3126E,circa 2002{Not a C7}?And if so,your comments please.I need some additional whoa power fast.Ford LT-9000--You're forgetting the 7.8 straight 6 Duramax--wish I had that instead of my kitty.Fellow excavator says it's an awesome engine--basically comes in same variations as Cat's 3126/C7.I think it's a sleeved engine-mine's not.I was about a month too early buying my truck when they got released.
Local Cat dealer uses them on their service trucks, they are running C7 engines though. I have asked the drivers and they don't have any problems. The only complaint I have heard is from the guys with auto transmissions they complain about the auto downshift working too good.