Mountain driving and jake brake question

[bevans6]

My bus has jake brakes but I haven't been able to make them work yet.  I suspect a simple electrical problem, but -

I have a trip I take once or twice a year that runs me up and down the I-79 - RTE 19 - I-77 run past Fancy Gap.  It's a common route south - I have an MC-5C, I'll be towing a 6,000 lb trailer, can I take this or a similar route safely with out jake brakes?

Thanks, Brian

[Airbag]

I'd say without the trailer you can safely drive any interstate in the US. But someone with more knowledge and experience should advise you about the trailer.

I don't have jakes also and was very afraid of the Grapevine south of Bakersfield but I have been told by a seasoned driver that he did it on a regular basis without jakes commercially with passengers. Brakes need to be in good shape.

[uncle ned]

  I have a 4104 with 6v92 and 730. I have jakes but i can come down fancy gap with out using them with no problem. Just start off the top at about 50 and let it coast.

If the trailer has brakes you may use them several times.

But the trucks will pass you. I don't remember hearing them using their jakes

The run off is straight and long so do not panic.

uncle ned

[bevans6]

I should add that the trailer has completely effective brakes of it's own, and they will be recently serviced so in top shape.

Brian

[TomC]

Just make sure your brakes are adjusted to 1/4 turn out and you should be alright.  None of the east coast hills are anything like the west coast mountains.  If you come out west, yes-have the jakes working. 
It's a simple matter to wire up a jumper to the Jakes so you can activate them manually as needed.  Good Luck, TomC

[Jerry32]

The thing to remember is not to rely on brakes alone as they will overheat and fade away. keepit under control with lower gears on the tranny only using the brakes as little as possible. it is scary when you push on the brake and nothing happens. Jerry

[fraser8]

Personally I would get the Jakes fixed. I've done the steep hills pulling a trailer and it can be a little hairy. I'm glad I didn't need to do an emergency stop near the bottom as it doesn't take much to make the brakes fade even if they are set up properly. I live in a mountain region with some very steep and long grades, it may be a little different where you live but why risk it. The Detroit Diesel dealer ran a quick electrical check on my jakes and didn't charge me. I recently changed all 4 solenoids and the switch on the engine and it was under $500.00.

[buswarrior]

For Fancy Gap, 3rd gear and use 45 mph as a target speed, when it hits 45, moderate brake application down to 40 and let it roll back up. You'll have to put the brakes on twice, maybe 3 times?

Great place to play with the balance between slope, aerodynamics, speed and gear selection.

The speed limit is 45 mph for big stuff going downhill anyway.

The 6000 pound trailer cancels out your 39 bums in seats.

FWIW, a Chrysler minivan will descend bang on the 55 the whole way with 5 guys in it, coasting in drive.

happy coaching!
buswarrior

[NJT 5573]

Brian,

Jakes leak off. They need oil in them to work. Sometimes they need up to a mile of use to reprime themselves.

You can also put them on and let the engine idle and if they prime, they will just kill the engine. May take several minutes.

You can wire around the safety switches, just make sure you don't put any fuel into it if you use it that way. Try a hot wire directly to the harness that goes into the valve covers to see if it will eventually start working and kill the engine. It won't hurt anything to do this and let it idle, even if it kills the engine. It will be noisy though, but be brave!

If that works, you can run a hot wire and switch from the drivers seat, just make sure you never get the Jake on and the throttle open at the same time. If you get it working you really need to run the electrical through the safety switches properly as soon as you can.

The normal switches are simple, one senses throttle position is closed so you don't/can't add fuel with the jake on and the other senses the clutch is engaged so the Jake does not kill the engine if you push the clutch in.

If you don't know the grade, slow will always get you to the bottom safely. Slow to me is about 10 MPH.

[TomC]

Most 2 strokers will not put out sufficient oil pressure to activate the Jakes at idle (I know mine doesn't).  If you rev the engine up to around 1200-you should have enough to activate and test the Jakes.  Good Luck, TomC

[bevans6]

What can you test electrically with the engine off, anything?  where is the wiring into the valve covers physically located, i can't seem to find it...   

thanks, Brian

[John316]

Brian,

I think that you will be fine without jakes, especially out east. We just got Jakes, but we haven't had them since we got the bus. That said, we have traveled a lot of places out West without Jakes. We have even done Grapevine, without Jakes (but that was one of those passes that cemented the decision to get Jakes ). So we have done the south route, and we have come back I 80 all the way, without Jakes. Also we have done Rabbit ears, no Jakes, but that wasn't a big deal since we were driving at a max of 10 mph (it was a blizzard).

So I think that you can do it without Jakes. Just be cautious, and don't try to win any races.

God bless,

John

[TomC]

If you have Jake brakes number one you'll either have the taller valve covers or a spacer between the stock valve covers and the head.  With the engine off you can pull the valve covers (not hard) and see if they are physically there.  Then you can take a positive jumper wire and try each Jake unit-you'll have two Jake units per head.  When you give the Jake juice, you should here a solenoid click from the unit if it is working.  Other then that, you have to have the engine running with over 30psi of oil pressure (typically on fast idle) to see if they actually are activating.  Good Luck, TomC

[JackConrad]

What can you test electrically with the engine off, anything?  where is the wiring into the valve covers physically located, i can't seem to find it...   
thanks, Brian

The wire goes each cylinder head just below the valve cover.  Jack

[mikelutestanski]

Hello;   I would want all the cards in my hand that are possible to have .. jake brakes or retarder or whatever...
   Just completed 5900 miles mostly eastern states but went as far a South Dakota   mt Rushmore area.. THere are plenty of grades East of the mississippi that are trying...
   THe Bus Warriors advice about speed and gears is the best and is honed from before the days of jakes and retarders..
    I follow religiously the yellow signs that give the suggested speed and gearing.
    I have a B400R  transmission and the R is for retarder..   I have used it and and works really well. West Virginia has a few really steep grades at 11 or 12% being 3 to 5 miles long .. I24 near nashville has a 4 mile 9% grade with a few twists near the top and bottom.
   My mci & is around 36 or 37K with a Saturn in tow..  I have a separate jake brake switch on the floor that applies only the retarder or  when the brakes are applied the retarder comes on also.. The control switch on the side panel allows the computer to activate the retarder when the other switches are on.   
    SO If you have the braking systems aboard make sure they work and use them..
   FWIW..    regards and happpy bussin
     mike