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exhaust brake PLUS Jake brake....3406

JDOFMEMI

JDOFMEMI

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My new truck has an ISX, and I am still learning it. The fan does not come on automatically, but I use it manually, and it is like another half of a setting on the Jakes. Not a lot of help, but some, and like you said, it does add to the noise level. I do agree that the ISX Jakes work better than the Cat, though my Cat has not had an adjustment in years, and I am sure that would help.

My KW with a 3406E had the fan switch on automatically with the Jakes.

Also, as stated above all of these things work best at holding you back with the engine near the governor.
 
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Birken Vogt

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lantraxco said:
The log trucks in my part of the world all used to have water tanks behind the cab, when you left the landing and started down, you opened the valve and let the water run on the brake drums.... also used to see stacks of fractured brake drums, but it helped in those days.
Click to expand...

My Dad was a mechanic in those days and said that cracked drums were usually a result of turning on the water after they were already hot. If they got water first and stayed wet then they did not bust.
 
R

RZucker

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JDOFMEMI said:
My new truck has an ISX, and I am still learning it. The fan does not come on automatically, but I use it manually, and it is like another half of a setting on the Jakes. Not a lot of help, but some, and like you said, it does add to the noise level. I do agree that the ISX Jakes work better than the Cat, though my Cat has not had an adjustment in years, and I am sure that would help.

My KW with a 3406E had the fan switch on automatically with the Jakes.

Also, as stated above all of these things work best at holding you back with the engine near the governor.
Click to expand...

I think I read that a 32" 9 blade fan could suck up 20HP+ at governed speed. I do know when the fan comes on in my junky old 86 Volvo with a 3406B, its very noticeable as far as power loss. It also has the 346 jakes that haven't been reset forever, but they seem to do the job. But this truck is lucky to run twice a month for a couple hrs. here and there.
 
Truck Shop

Truck Shop

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The DD15 series has the best jake of any that I have driven,IMO. They accomplished it by actuating the exhaust valve twice to totally expend the
energy created on the compression stroke. So the piston is pulling against a dead cylinder expending total energy to pull the piston down.

Truck Shop
 
Truck Shop

Truck Shop

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This thread has me remembering that Cat had a model of Jake for A's and B's called quote ** the Super Jake** unquote. The model is a 349A, the standard
model was the 346B. The 349 was 25 to 30% stronger. To verify that I called a friend of mine that is an ex Cat Mechanic that now teaches diesel at the
Walla Walla St. Penitentiary. Know as Mr. Penner, that is his real last name. If the OP could find a set of the 349A's it would take care of the jake issue.
We had a owner operator that had a set on a 7FB 400 that were real strong for a Cat. Hope this helps.

Truck Shop
 
L

lantraxco

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Jake also had an upgrade kit for the 349 series called a "B+" kit to increase braking in the 3406B models. If you want the best performance and life, you would want the latest 349D setup I should think. YMMV.
 
Truck Shop

Truck Shop

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lantraxco said:
Jake also had an upgrade kit for the 349 series called a "B+" kit to increase braking in the 3406B models. If you want the best performance and life, you would want the latest 349D setup I should think. YMMV.
Click to expand...

Thanks for adding that, I forgot to. Too many irons in the fire for Sunday.

Truck Shop
 
T

tnc110

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Good info, thank you! I'm kinda wonder if I'm pissing in the wind though. I'm grossing 95k, right now there is a grade that I have to go down that requires 1st gear, and I still have to use the brakes. I might be asking too much out of this Ole girl?

How do I verify which jake I have now?

Truck Shop said:
This thread has me remembering that Cat had a model of Jake for A's and B's called quote ** the Super Jake** unquote. The model is a 349A, the standard
model was the 346B. The 349 was 25 to 30% stronger. To verify that I called a friend of mine that is an ex Cat Mechanic that now teaches diesel at the
Walla Walla St. Penitentiary. Know as Mr. Penner, that is his real last name. If the OP could find a set of the 349A's it would take care of the jake issue.
We had a owner operator that had a set on a 7FB 400 that were real strong for a Cat. Hope this helps.

Truck Shop
Click to expand...
 
L

lantraxco

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I guess I would say it depends... axle ratio, transmission model, tire size, steepness and length of grade. As long as your brakes are not smoking hot at the bottom I would think you're golden.

Pop a valve cover off, I think the model number is cast into the jake units? If not there should be a tag.

Talked to a heavy haul driver back in the day, had 500+ hp CAT, 15 speed with deep reduction, four speed brownie and two speed drivers... hauling precast concrete bridge beams onto Mt. St. Helens to rebuild the road after she blew with a second driver in the race car under the load at the back. On the last pitch he said he was all in, everything in the last low gear, never spun a wheel just flat ran out of power. They brought a D9 down to help him the last couple hundred yards. Sometimes no matter what you got, it just ain't enough.
 
B

Birken Vogt

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tnc110 said:
Good info, thank you! I'm kinda wonder if I'm pissing in the wind though. I'm grossing 95k, right now there is a grade that I have to go down that requires 1st gear, and I still have to use the brakes.
Click to expand...

I just can't wrap my brain around this. How steep and how slow are we talking about? 1st gear must be good for 1 mph?
 
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tnc110

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I was in my Sterling when you posted, it runs about 9 miles per hour in first gear governed speed. I would say the Peterbilt is running at least five probably 7 miles per hour
 
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Birken Vogt

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It seems to me like you may have kind of a tall transmission and/or rear axle for this kind of thing.

According to the only horsepower calculator I could find, it returns 377 HP at 95,000 lbs on an 18 percent grade at 7 mph. That is for going uphill so downhill will be a little less because gear losses work for you instead of against you.

If that calculator is worth anything.

I don't think the old 3406 Jakes ever got 377 HP even when they were brand new. I can't find a chart of it but the 3406c only got to about 320 @ 2000 RPM.
 
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