My brakes come on while driving my 3500 15 passenger dodge van. By "come on" I mean I'm going down the highway and the brakes actually come on without me pushing on the gas pedal at all. They stick on and I have to floor it to build enough speed until I can pull over somewhere. I then pull over to the side of the road and wait for 5 minutes and wait for the brakes to cool off and it won't do it again for the day. I've replaced everything from the brake fluid to every hose and brake parts. It only happens in the summer. Any ideas?

 

front brakes, rear brakes or both? left, right side or both?

 

Front right brake comes on.

 

collapsed rubber hose on the right side... common problem

cheap enough to just replace to make sure that is NOT the cause as you said you replaced all the hoses...

 

I'll check thanks!

 

I was going to suggest that but the OP said he replaced all the brake hoses.

 

The caliper could also be sticking but I would replace the line again just to be sure. I had a truck that used to have s sticky caliper and I used a c-clamp to run it through its full travel to free it up. That would work for a few months before it got stuck again.
Steve

 

sticky caliper for sure...
take it off, leave it hang from the wheel hose attached and with the help of a coat hanger to relieve the weight off the hose or get someone to help you and use a large C-clamp as SteveR said to press the piston down as far as it will go remove the clamp then
slowly pump the brake pedal so that the piston extends out, only about 1/2 to 3/4 inch and press it back again to try to free it up
if it does not free up and travel freely then replace that also... not real expensive

 

How do you know it's the RF?