I am installing new helper springs on my 94 F150 Extra Cab LWB tonight. In reviewing the installation instructions it says that after installation, the load-brake proportioning valve must be adjusted or the brakes will not work properly when the truck is under a load.

My first question is, Is this necessary? I only ask because I haven't read or heard of others performing this step. If it is necessary, is this step simple to perform or should it be done by a certified mechanic? Can the steps be found in a Chiltons/Haynes manual?

 

Hi Skiwampus and welcome to FTE

I think the proportioning valve they are talking about would be the old style one above the rear diff with a lever that goes down to the housing. Your truck doesn't have that.

 

Thanks for the reply Racerguy. However, because of my ignorance, your response that the valve was found on older trucks confuses me a little bit more. Here is the exact text from the installation instructions. Granted these instructions are not provided by Ford and may or may not be accurate. I just want to make sure that I do this properly.

"Many light trucks manufactured after 1985 are equipped with a load-brake proportioning valve. The valve allows increased brake pressure to the rear wheels when a load is applied to your vehicle. Adjustment of this valve by your local truck dealer is required after this helper kit is installed. Failure to to have the load-brake proportioning valve adjusted will result in improper and/or unsafe brake operation when your vehicle is loaded."

I didn't buy the helpers to increase my load capabilities but to better handle the loads for which the truck is designed. Shouldn't the valve (if I even have one) be already be adjusted to properly handle the prescribed loads?

 

If your truck had that type of valve it would probably have to be adjusted but it doesnt have it so you have nothing to worry about
The valve they are talking about was on the trucks before they had ABS. It was attached to the frame above the rear axle with linkage that went to the axle housing. If the truck was sitting higher (unloaded) it would cut some pressure to the rear brakes. When the back of the truck was loaded and sitting lower it increased the pressure to the brakes. I think the last year that they used that was 1986 but I might be wrong.
The instructions they gave you are pretty generic to cover a lot of different years and models.
I put an extra leaf in each side of my 1992 F150 4x4 Supercab to handle towing the race car better. It helped a lot. The truck sits level with the trailer on behind and handles better.
Let us know how it works out for you.

 

Thanks for clearing that up for me. It's good to know that I don't need to worry about that part of the adjustment. Thanks for your help.