Shilohman

Just got of the phone with Kathy at a PacBrake dealer 998.00 shipping included,this also is the air tank,and accesories.Found a dealer dumping a Jacobs brake kit on E-Bay for 835.00 plus shipping.Thoughts?

ratsun

Does the Jacobs come with a spare vacuum pump?
If you do a search you will see a lot of members have had the Jacobs pumps fail?
I vote spend a little more on the Pac now.

bansh-eman

I did a little research when I was hauling heavy, and everyone pretty much says the only way to go is PAC, But I can't say from personal experiance.

92'1stGen

I like my Jake and I've been happy with it. No vacuum pump problems in 42k miles, and I use it a lot, every time I come to a stop.

CoastalDav

Who's dumping the Jacobs E-Brake? Good price. Cheapest I've seen it was 1035.00 dollars at Machanicville Dodge.

Dave

Det 1

Good price on the PacBrake, too. Best price I found a week ago was $1225 for the 4" model and $1425 for the 5" remote model that I purchased from DTR.

n2moto

I have the pac and I'm happy with it I use it all the time. I too have read many posts on this site and others about the Jake pump failures. I'd spend the extra on the Pac with the tank and acc's. I think it's a no brainer.

KWKING

I would think $998US including shipping is pretty darn good.They are about $1300 Canadian ,less tax out of PacBrakes door just 20 minutes from me.

AH64ID

Both my dad and I run the Jake's. I have 40K on mine without issue, and he has over 50K...

Personally I like the Jake becuase the pressure increases with rpms, there are times where its just too much braking, so I upshift. With a Pac you get max pressure all the time.. and that wouldn't work for me.

dakotajam

I vote for the Pac Brake
It will work in all gears with a 47re. I have not had the need to use it below 3rd gear. 6 to 7% grade on Black Mountain slows to below 45mph with out service brakes.
The aux. air is a good thing when camping.

John

CTD NUT

There is a little misinformation there.

The Pacbrake also increases retarding power with engine rpm. This is the nature of any exhaust brake. However, the PRXB regulates internal blow of pressure at higher rpms to maintain the 60 psi back pressure. The jake just has a hole that bleeds off pressure at ALL rpm and back pressures - not good for lower rpm retarding power. The difference in performance is significant. I have run both styles of EB and I'll take the PRXB hands down. I spend a lot of time running around empty and the PRXB is as smooth and controllable at all rpms compared to an unregulated brake with the main difference just being increased retarding power at lower rpm.

I find that I can stay in higher gears longer when braking and do not have to down shift anywhere near as early to get the required braking power - it is much nicer, period.

AH64ID

I don't see the misinformation. How is saying max pressure and different than saying it maintains 60psi.. since 60 psi is max pressure. If I had said max retarding, then yes that would have been misinformation.

At 3200 rpms the braking on the two is the same, infact from 2500-3200 the braking is the same. Its below those rpms, as you said, that the Pac has more braking.. and thats what I don't want.. Like I said my Jake provides too much braking below 2000rpms at times.

On the same note, has anyone seen this Banks Test?



Since retarding hp is a measure of pressure and rpms how can PAC and Banks (Banks much more so) provide more braking hp and not exceed the 60psi set by Cummins??? (On a side not the Jacobs produces up to 63psi on my truck, Jacobs said that 65 was the real max and if you exceed 70 you will have problems)... But since pressure is pressure and rpms are rpms that tells be the Pac and Banks exceed the max pressure.

CTD NUT

You implied that the PRXB did not ramp up retarding power like the jake, which is not true.

Max backpressure is 60 psi as stated by Cummins. The PRXB blows of excess pressure to maintain that 60 PSI. The jake, by design, is not capable of regulating pressure.

Are you talking about peak retarding power or average retarding power across the operating rpm? If you are talking peak power, I'd expect that the EB's are similar with the difference being that the size of the hole in the jake butterfly is sized according to max engine retarding rpm....that hole is detrimental to performance everywhere below peak retarding rpm.

The PRXB really shines with average retarding power since it is capable of maintaining 60 psi well below peak retarding power rpm. This is where an unregulated brake falls short. There is more retarding power across the board and the engine does not have to be revving anywhere near as high to provide adequate retarding power to slow an empty truck down.

The regulated brake can be smoother and more enjoyable to drive when empty since you can stay in higher gears without the need to down shift as soon to brake well.

By nature, the regulated brake is more likely to maintain a given back pressure than an unregulated brake. The PRXB is set to 60 psi and does a good job of maintaining that pressure and I think it is facetious to suggest it does not while an unregulated brake does.

AH64ID

I see where you read that now, and have fixed my post.



Correct, the hole in the Jake is calibrated to provide 60psi max. It achieves this pressure from about 2500 rpms up.



I am talking peak retarding power. Which is acheived with max rpm and max pressure. So all the brakes should be equal (thou the PXRB and Banks are higher than Jake, which makes me wonder about the pressure on the PXRB and Banks, or the test which banks preformed).. If the PXRB holds 60 across the board then the retarding power of the PXRB and Jake is equal from 2500-3200, and after a hot hill climb its as low as 2350-3200.

What you consider falling short I consider a positive. I like that the braking pressure decreases with rpm, I find it much easier (in theory) to control speed when i can pick retarding hp. These brakes are very effective and quite often I upshift to reduce psi to get the braking I need.. I don't think (in theory) I could do that as well with the PXRB. i.e if I put in in 6th at 65 mph I am at 1875 rpms, which is about 50psi and I hold the speed. If I need more braking then I downshift to 5th and am at 2575 rpms and have 60psi. But more often than not 6th will be the correct amount of braking and the brake doesn't cycle as often (which I prefer)... The PXRB will have 17% more retarding pressure at 65 in 6th and the brake will have to cycle much more often..

So it comes down to brake cycling, I prefer mine not to cycle all the time.

I am just stating that the Banks test shows the PXRB having more retarding hp than the Jake.. There are only 2 ways to do that, psi or rpm.

carbuff415

I upgraded to the PRXB when it came out. Before that, I have the plain orifice style. I prefer the PRXB.

If it is possible, I would recommend trying to find someone locally that has one of each. Go for a test ride and look at the installations of each to make your final decision on which one you like best.