In the manual for my new Air Lift ride controlers it says: "Your vehicle may be equipped with a rear brake proportioning valve. Any type of load assist suspension product could effect brake performance. We recommend that you check with your dealer before installing this type of product."

I am pretty sure my 04 5.4l fx4 has a proportioning valve, what should I do or watch out for?

 

I'm pretty sure the 2004s use the ABS to prevent rear wheel lockup instead of a load sensing prop valve.

but not positive... better check with a dealer...

 

I think mine may be opposite than that. I have a brake hose that branches off the rear distribution block and is mounted above (proportioning valve?) and only have wires (to sensors) to the front hubs.

 

I understand what they are talking about, but I think they just put that in the manual just to cover their a--. I have Firestone Ride-Rite bags under my truck and I have never noticed any issues that would require messing around with the proportioning valve, and I have had mine loaded VERY heavy (6000lbs once and over 3500 lbs a 6-7 times). I wouldn't worry about anything at all, just put the system in and use/enjoy it.

 

Good to know, thanks.

BTW, great looking truck, any rubbing issues with those tires? How do they do in the snow?

 

Thanks man!! They only have rubbed 5-6 times in the 3+ years that I have had them on. I have only had them in the snow once, I always put the stock wheels/tires back on for winter.