Pacbrake PRXB?

[Fred Swanson]

Okay, brake is adjusted and a little air feed modification, and all is working great. I like the feel of this 5 inch compared to the older design 4 inch I had.



I spoke to Piers today to see how his was doing, and his is working great too.

Piers and I are running the control group(compressor, relay/solenoid in one neat package).

I also had added a 2. 5 gallon tank for other air needs. I can tell you the air cylinder on this new 5 inch is much larger than the 4 inch(as it was designed for a different motor than the 5. 9), plus the return spring tension along with the pressure release valve, requires a higher apply pressure, from my testing.

If my tank reserve pressure drops below 90, the brake feel is less, and according to my drive pressure/back pressure boost gauge, I'm not getting the 60psi I'm looking for.

When I have over 90psi in the tank, like right after the compressor kicks off, I get my 50-60 psi at a lower RPM, then the 4 inch, I feel. The brake does a nice job at the lower RPM's as advertised, and for an installation that was not originally intended, it is doing good, I feel.

Now, because I have the reserve air tank, and I want to increase the total reserve capacity, for other needs, I am going to change the compressor over to possibly an engine driven model.

 

[thejeepdude]

I am going to change the compressor over to possibly an engine driven model.

If you go the Kilby bracket / York route, let me know how it goes... considering the same setup. With the York you don't even need a tank. I run an air ratchet straight off the York in my Jeep.

 

[Gypsyman]

I also had added a 2. 5 gallon tank for other air needs. I can tell you the air cylinder on this new 5 inch is much larger than the 4 inch(as it was designed for a different motor than the 5. 9), plus the return spring tension along with the pressure release valve, requires a higher apply pressure, from my testing.

If my tank reserve pressure drops below 90, the brake feel is less, and according to my drive pressure/back pressure boost gauge, I'm not getting the 60psi I'm looking for.

Fred,



Does the air cylinder bleed off a lot of pressure or leak? How fast does it drop under 90 psi? Please tell me that it will hold over 90 psi down a long grade. On the other hand it may be a good excuse to get the Kelderman Air-Ride. :-laf





Richard

 

[Fred Swanson]

With just the control group and brake like what Piers is running, the compressor is only feeding the air cylinder, and can keep it up to snuff.

I only notice it if I use it several times in a row. There is a small bleed port on the air cylinder, but no noticeable air loss is present. Because I'm trying to keep a 2. 5 gallon tank full, I notice it, and the compressor is just not putting enough volume for the job, so I'm looking at options to go to an engine driven compressor.

I run a Sanden on my Samurai, have for years, so I'll look to do the same on this setup.

I have another Sanden, I'd like to use it, if I can. But I can do the York, if that works easier.

 

[Gypsyman]

Fred,



Any updates with a different air supply? I've got mine on and I agree with the need for more air to get a decent engagement time. The cylinder is way too large for the standard air group and without enough pressure and volume this thing is a dog for application time compared to the Jacobs I had. Nice piece otherwise though.



Richard

 

[SRadke]

I'm running my 4" from an auxillary tank with a solenoid. There's no reason your 5" couldn't be done the same way, and use a 1/4" solenoid rather than my 1/8" if it's too slow. All you need is an electric compressor and a tank.



-Scott