Jake brakes 8v71

Barn Owl · September 14, 2014, 05:00:09 PM

8v71s are some tough iron. I have only ever had 5 at idle and 30 at speed. The minimum spec according to Detroit BTW. I have newer iron sitting ready to go in but as long as what I have keeps going, then I have better things to do with the kids.

I am lucky, my bus came from the PO with Jake's and they are set up quite well, steep grades and quite often no brakes. I do hills both east and west that most here would not consider, but I will admit that if you are careful you can get by without them, mostly I leave them off and use a momentary foot switch that I use like an on/off brake. The bottom line for most is that a lot of those without them seem to want them, and it is easy to go to the boards looking for justification. If you want them and you can afford it then do it, especially if it makes you feel more comfortable and removes any anxiety over the issue. Also as was mentioned by Brian, I seem to use mine a good bit in the stop-and-go traffic of the city, so they are not exclusively just for the big whoop-de-doos. So my take is: Fun to have, not required.

TomC · September 14, 2014, 08:30:15 PM

When I was driving my first Diesel truck with 6-71, I never checked the oil. I knew it was time for a gallon when the oil pressure went from 32 down to 28. I let the engine idle all night once while I got a Hotel room it was so cold out. In the morning there was an oil puddle about a foot around under the engine. It didn't care. Good Luck, TomC

OneLapper · September 16, 2014, 06:16:19 AM

I completely agree with Barn Owl. If you can afford and want Jakes, get them.

I bought a set for $500, spent $300 on the rebuild kit, another $200 on switches, etc., and I installed them. I love using them, definitely part of the 'fun factor' of driving the bus.

On the otherhand (if you can even say that) everything Clifford says about setting them up is true, too. If it's not done right, Jakes aren't very effective on a two stroke. I got lucky, I installed new injectors and the old time marine DD wrench was thrilled to see Jakes again. He had all the tools and manuals. After his tune up my Jakes worked better than I ever had them working. All that said, I'm happy with them, they work great, I use them all the time (maybe even too much), I don't regret the expense. We own these buses because they are fun, right? Right!

chessie4905 · September 16, 2014, 06:40:07 AM

You better check the gauge or sending unit. No way you have that much pressure. I think the low pressure warning is set for 4 psi. Detroits are known for low idle pressure and bearing problems aren't a normal issue. (at least on 71 series) 6-8 at idle and 25 to 40 at rated speed is common. A Lot of oil is bled off those engines for lubing accessories.

Ed Hackenbruch · September 16, 2014, 06:47:54 AM

The Operating Manual for my 5A says, " normal readings with engine hot are; Idling 11 lbs. minimum. Governed Speed: 30 lbs. minimum. Engine must not be operated when oil pressure falls below 30 lbs. at governed speed under full load."

luvrbus · September 16, 2014, 07:10:52 AM

Turbo engines will have less oil pressure than the N/A engines they will run forever at 5 lbs at idle and less than 30 lbs of oil pressure so I wouldn't worry about the 11 psi at idle

Back to Jakes they say 15 lbs min oil pressure lol I can't get them to work around 20 lbs. Gearing plays a big part in the oil pressure buses with the 4:11 and above carry more oil pressure and the Jakes work better I gotta do this ::)but if you want more oil pressure dump the Delo 100 and go with the Delvac 1240

IMO they work better with the 730 and standard than they do with the 600 and 700 series Allison's

Ed Hackenbruch · September 16, 2014, 08:13:57 AM

Where do you find the Delvac 1240? Have never seen it on the self anywhere, only the Delvac 1300.

Boomer · September 16, 2014, 08:38:00 AM

Using jakes in the city is for cowboys.

luvrbus · September 16, 2014, 08:44:08 AM

You can get it Vegas ED at Western Petroleum on the north side

chessie4905 · September 16, 2014, 10:59:13 AM

Get the jakes now as they are going to be harder to find used and be more expensive in the future.

bevans6 · September 16, 2014, 01:42:42 PM

I have Jakes on my bus, and with my new resonator muffler I can actually hear them come on now. My wife followed me a bit, and said they could be heard behind the bus no problem. I make sure to have them off in town, but earlier this summer I went to Mosport, big name race track just outside Toronto, and they have a big new tunnel for big rigs to get inside the track. I made sure to be in first gear and with the jakes on going through that tunnel, and the sound was glorious! I live on a road that lumber trucks pass by, and some of those are straight-piped and have seriously loud jakes, I like the sound of a truck working. Loud motorcycles (the really loud straight piped ones) piss me off, that is noise for noises sake, but a truck working hard for a living I like. I wave, they wave back. It's a Maritime thing maybe.

Brian

lvmci · September 16, 2014, 05:38:08 PM

Hi Ed, Mobil delvac 1240 40W as Clifford said, Western Refineries, 7022697880 Debbie Haynes, 2949 No. Lamb, North Las Vegas, Nv. They are the Mobil Oil Distributers, 5 gallon pale $81.85, lvmci...
PS, when you come for the dam rally you can pick some up!

eagle19952 · September 16, 2014, 05:52:17 PM

I like the sound of a truck working. Loud motorcycles (the really loud straight piped ones) piss me off..
they actually save lives...really. people tend to swerve away from the sound versus towards it...

Tell me again how hard your bus is working...

harleyman_1000 · September 23, 2014, 03:28:27 PM

Quote from: bevans6 on September 16, 2014, 01:42:42 PM
I have Jakes on my bus, and with my new resonator muffler I can actually hear them come on now. My wife followed me a bit, and said they could be heard behind the bus no problem. I make sure to have them off in town, but earlier this summer I went to Mosport, big name race track just outside Toronto, and they have a big new tunnel for big rigs to get inside the track. I made sure to be in first gear and with the jakes on going through that tunnel, and the sound was glorious! I live on a road that lumber trucks pass by, and some of those are straight-piped and have seriously loud jakes, I like the sound of a truck working. Loud motorcycles (the really loud straight piped ones) piss me off, that is noise for noises sake, but a truck working hard for a living I like. I wave, they wave back. It's a Maritime thing maybe.

Brian

Just wanted to let you know Loud pipes save life's Riding a bike is dangerous when people pull out in front of you!

bevans6 · September 23, 2014, 04:26:42 PM

Loud pipes can only be heard behind you. They do nothing for left turners or anything else, this backed up by insurance studies. I say this as a motorcyclist and instructor for 40 years. I ride with quiet pipes. I have no time for straight-piped bikes, I want them outlawed and off the streets.

Off topic or what?

Brian