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Foretravel Motorhome Forums => Foretravel Discussions => Topic started by: Old phart phred on June 12, 2017, 11:13:42 pm

Title: 3208 Jake brake
Post by: Old phart phred on June 12, 2017, 11:13:42 pm
Does anybody have any idea of what it would cost to add a Jake brake to a 3208? Was it ever a factory option?
Title: Re: 3208 Jake brake
Post by: craneman on June 12, 2017, 11:35:49 pm
An exhaust brake will work on one.
Title: Re: 3208 Jake brake
Post by: wolfe10 on June 13, 2017, 09:25:11 am
Yup, no jake brake (engine compression brake) on a 3208.

You can check with PacBrake using your engine serial number to see the Caterpillar spec for max back pressure with an exhaust brake.  May or MAY NOT be worth it-- depends on max allowable back pressure.
Title: Re: 3208 Jake brake
Post by: Chuck & Jeannie on June 13, 2017, 10:09:12 am
Expanding on Brett's comment concerning exhaust back pressure: my recent treatise on our exhaust brake.  Not a PacBrake, but similar concept.

D-Celerator Exhaust Brake (http://www.foreforums.com/index.php?topic=28753)
Title: Re: 3208 Jake brake
Post by: Mike Leary (RIP) on June 13, 2017, 10:39:27 am
Whatever it costs, if you push down the hills out west, you will "never leave home without it!"  ^.^d
Title: Re: 3208 Jake brake
Post by: wolfe10 on June 13, 2017, 10:41:52 am
Mike,

When was the last time you lubed the PacBrake: Maintenance | Pacbrake (http://pacbrake.com/supplemental-brakes/prxb-exhaust-brakes/maintenance/)
Title: Re: 3208 Jake brake
Post by: Mike Leary (RIP) on June 13, 2017, 11:01:27 am
When was the last time you lubed the PacBrake ?

It was serviced just before we bought the coach, in late 2014. Not a lot of miles since, but, good point. Any clue how often?  ^.^d
Title: Re: 3208 Jake brake
Post by: Chuck & Jeannie on June 13, 2017, 01:15:04 pm
It was serviced just before we bought the coach, in late 2014. Not a lot of miles since...
It's not the miles that kill exhaust brakes...it's the sitting.  When you drive (and use it) it gets exercised.  Sitting, it rusts and locks up.
Title: Re: 3208 Jake brake
Post by: Mike Leary (RIP) on June 13, 2017, 01:24:32 pm
It's not the miles that kill exhaust brakes...it's the sitting.  When you drive (and use it) it gets exercised.  Sitting, it rusts and locks up.

Other than asking the DW, "How about a trip to Nova Scotia?", is there any way to beat the lag when sitting?  :-\
Title: Re: 3208 Jake brake
Post by: wolfe10 on June 13, 2017, 01:50:36 pm
Yes, lube it more frequently when sitting.  The oil helps keep them from rusting up.
Title: Re: 3208 Jake brake
Post by: rkohl on June 13, 2017, 02:34:31 pm
A few years back I put an exhaust brake from BD Performance on my 3208 Cat. After one trip to the Rockies without one I had to do something. I believe the limitation was 25 PSI. The brake was set up to open if the pressure got to high. You had to be in the right gear, at the right RPM for it to work. If memory serves me it was 3rd gear at 2000 RPM. It made driving in Colorado doable again but it did not get used much other than that. Well worth the money.
Title: Re: 3208 Jake brake
Post by: Caflashbob on June 13, 2017, 02:49:35 pm
Rkohl's comments match my experience.  Had a few customers install the d'cellerator in both 3208 and 8.2DD.

If you kept the revs up the hold back was helpful on big downhills.

The service brakes on the ORED's were unusual as the fronts did not come on till the brake pressure went over 60 psi.

So riding the brakes will get the rear drums only.

Better to get on the brakes hard then back off for a bit.

I have had smoke out of the rear wheels and the fronts cool to the touch.

If you remove the dash lq4 valve that controls this you will get a shuddering vibration in reverse at slow speeds

Gillig bus chassis shuddered in reverse because of the normal primary/secondary brake shoe setup.



Title: Re: 3208 Jake brake
Post by: Chuck Pearson on June 13, 2017, 03:34:02 pm
Yup, no jake brake (engine compression brake) on a 3208.

You can check with PacBrake using your engine serial number to see the Caterpillar spec for max back pressure with an exhaust brake.  May or MAY NOT be worth it-- depends on max allowable back pressure.

Important consideration here.  Had a friend  who went through this, turns out some  3208 engines have valve springs that will accommodate an exhaust brake, some don't.  Definitely a good place to start the decision process.
Title: Re: 3208 Jake brake
Post by: Caflashbob on June 13, 2017, 04:51:07 pm
He says something is installed already
Title: Re: 3208 Jake brake
Post by: Old phart phred on June 13, 2017, 08:43:55 pm
Ask the current owner of a for sale 3208 if it had an exhaust brake, he told me no it has a Jake brake. So untill I get to inspect it,  it will be a I don't know JACK brake.
Title: Re: 3208 Jake brake
Post by: Caflashbob on June 13, 2017, 09:40:50 pm
Exhaust brakes worked better on naturally aspirated cats.  Higher static compression ratio.  636 cu inch.  More compression. More hold back.  N/a were 185hp.  Gutless.  81 FRED had them.

The exhaust brake as wolfe10 mentions can require servicing as the unit valve would seize.  Copper high temp lube?

Title: Re: 3208 Jake brake
Post by: wolfe10 on June 13, 2017, 10:10:57 pm

NO. PacBrake has their own high-temp synthetic lube.  Under $10 for a lifetime supply: http://www.xtremediesel.com/pacbrakec18037maintenancelube.aspx
Title: Re: 3208 Jake brake
Post by: Caflashbob on June 13, 2017, 11:03:29 pm
Hence the question mark as in 1989 the copper stuff was the lube. Don't know why thirty years later things would change.
Title: Re: 3208 Jake brake
Post by: Bill Willett on June 14, 2017, 09:20:05 am
Hence the question mark as in 1989 the copper stuff was the lube. Don't know why thirty years later things would change.

1- it is called progress
2- we have much better lubricants.
Title: Re: 3208 Jake brake
Post by: Caflashbob on June 14, 2017, 11:19:55 am
That's nice
Title: Re: 3208 Jake brake
Post by: Jet Doc on June 17, 2017, 12:31:16 am
In my experience an exhaust brake makes a little noise and maybe you feel a slight tug...where as a true "jake brake" makes your seatbelt get snug.  Not poetry just an observation.
Title: Re: 3208 Jake brake
Post by: Chuck & Jeannie on June 17, 2017, 07:39:39 am
My (Opinion) List of Auxiliary Braking Devices, in order of effectiveness, versatility and desirability:

1.  Hydraulic (or Electro-magnetic) Transmission Retarder

2.  True compression release "Jake Brake" built into engine

3.  Variable Geometry Turbo (rare)

4.  Aftermarket Add-On Exhaust Brake (air or electric operated)

5.  Gravel filled emergency Runaway Truck ramp

6.  None of the above (service brakes only)
Title: Re: 3208 Jake brake
Post by: lenspeiser on June 17, 2017, 07:43:15 am
Chuck,
You left off:

5. Low tunnel clearance.

 >:D