Help! My 2006 Honda CRV has no brakes on highway with cruise control on!

Please help! I have a 2006 Honda CRV with a manual transmission and the brakes have failed twice while I was trying to stop quickly on the highway with the cruise control on. The first time this happened, the car was 6 months old and the dealer replaced the master cylinder. It happened again yesterday - a car ahead of me had spun out of control and there was a semi in front of me on the highway. I hit the brakes hard and the car wouldn’t slow down and I almost ran into the semi. I think I had my foot on the clutch while I tried to slow down the car but can’t remember for sure as I thought I was going to get killed. I then popped it into neutral, undid the cruise, hit the brakes (which then worked) and ended up on the grassy median. This only happens when I have to stop quickly at highway speeds with the cruise on. If I lightly tap the brakes at freeway speeds while on cruise, it disengages the cruise control and the car slows down (i.e. it functions normally). The A/C was on low yesterday and completely off the first time this happened. My friend thinks I have a vacuum problem and that there is not enough vacuum to disengage the cruise control when I have to hit the brakes hard. What is wrong with my car and can this problem be repaired and is it safe to use the cruise control? I avoided a major accident and possibly killing someone or myself twice now and it is very scary. Any advice or suggestions would be very helpful. Other than this problem, I love the car. It has 50,000 miles on it. I am taking it to the dealer today but would very much appreciate your expertise as I have gotten wonderful advice from this site before. Thanks! Catdoctor

Is it safe to use the cruise control?! You almost hit a semi and you’re asking if it’s safe to use the cruise control?!! Lord no it’s not safe to use the cruise control!

Take it back to the dealer, tell them what is happening, make them look over the entire cruise system and the braking system. I am guessing that the dump valve that disengages the cruise control servo is sticking, and not opening when you press the brakes quickly.

Your friend could be right, it could very well be a vacuum problem, but really, when you step on the brake you are removing the vacuum condition from the cruise control servo, and allowing it to drop back to its disengaged position. Get it checked out before you regret it!

I brought it to the dealer who could not recreate the problem so they said to just go drive it and occasionally test it when there is no traffic! I will try another mechanic. Thanks for the help. Catdoctor

If you’re in a situation such that you feel that an emergency stop might be necessary, the cruise control should simply be turned off anyway.

The cruise control is disengaged by a switch on the brake pedal, usually integrated with the brake light switch, or by the brake light switch itself. Are the brake lights working properly?

Obviously, you shouldn’t use the cruise control until the problem is solved.

Yes, the brake lights are working fine. The dealer couldn’t find a vacuum leak or anything wrong with the brakes or cruise control. This problem is very frustrating!

It seems that there is a delay from the time you hit the brake pedal until the cruise control disengages. I can’t see the brakes losing their power boost (from engine vacuum); rather, I think that the engine is still pulling at the same power level, for a few moments after you hit the brake pedal, as that which it was producing before you hit the brake pedal. Thus, the brakes would be trying to overcome the engine pull as well as trying to retard the vehicle’s speed.

Try to simulate the condition by driving the vehicle at 60 mph, and hold the gas pedal to maintain that speed. While holding the gas pedal down (for 60 mph) with your right foot, hit the brake pedal with your left foot. Does that feel like the same underpowered brakes as you experienced before?

You should call the regional representative for Honda of America with your complaint. They won’t brush you off because this is a safety issue. Also, file a complaint with the NHTSA (National Highway Traffic Safety Administration). This kind of problem can result in a safety recall of Honda CRVs.

I was using a 04 model of the CRV and a manual transmission and I noticed the same problem. Unfortunatly I had 3 seperate shops look at it and they all told me the same thing. They suggested that you not use the cruse in anything but light traffic due to the “lag time” between brake and cruse disengagement and I make the same suggestion to you.

Does this vehicles cruise control even have a vacuum component? Or is it all electronic?

If that problem is common, and that’s their suggestion for seeing to the problem, then I believe the NHTSA should be notified. At highway speeds with the cruise on, how are you supposed to know when you might need the brakes? What if you are all alone on a rural road and a deer pops up in the road? I think Honda best be figuring out a way to fix that.

Skipper