Originally Posted by AH64ID (Post 2632828)

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.

Originally Posted by AH64ID (Post 2632828)

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.

Originally Posted by CTD NUT (Post 2632851)

This is your theory that I'm taking as conjecture. It does not play out in practice how you have theorized it. You obviously need to drive a truck with a PRXB. After owning and driving trucks with a standard Pac, Jake and PRXB, I'll take the PRXB hands down. There is no additional cycling of the brake, either.

Originally Posted by CTD NUT (Post 2632851)

I agree, and I don't not have an argument or explanation for one brake generating more peak retarding power over another if we can assume they all hold a max of 60 psi of back pressure. Average retarding power is a very different story...which I happen to think is more important.

Originally Posted by AH64ID (Post 2632895)

but on a manual where I can always get my rpms to 2500-3200 I will stick with the Jake... just my .02 (thats whey we love America)

Originally Posted by CTD NUT (Post 2632921)

Ahh....I'm understanding more about what you mean by the brake cycling. The PRXB has a small internal blow off valve in the large, main butterfly valve that does all of the regulating. The large valve does not budge when regulating the pressure - it is either open or closed. The small blow off valve is designed to react fast and work rapidly and has nothing to do with the main valve operation. The small blow off valve is certainly time proven to work well and be very durable. There are a lot of PRXB's out there and you hear very little complaints about them.

Originally Posted by CTD NUT (Post 2632924)

And all I'm saying is that you don't have to rev that high to do the same thing with a PRXB. When I am empty, I engage at 2500 rpm and slow down from there. When I don't have to slow down in a hurry, I can engage a 2000 rpm and slow down from there and down shift at around 1600 rpm. There is no need to rev higher....all the braking power you need occurs earlier.

Originally Posted by AH64ID (Post 2632929)

I don't think we are refering to the same cycling. I am talking where the brake goes on-off-on-off-on-etc.. when descending with the cruise control on. That drives me nuts.

Originally Posted by 92'1stGen (Post 2630581)

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.