Hello all, My car has a rough idle, only when it gets below freezing outside temperature. It comes out of it when the car warms up and it won't do it when the outside temp is above freezing. Like I said it only does it when it sits overnight and the temperature is below freezing. There is no check engine lights on etc...The brakes won't work and cruise control will not work. I have changed the breather hose and imt rings have been replaced. Please help. I am at a loss, it's weird the only time it acts up when the outside temp is really cold..I need to get it fixed this weekend. Please help. Thanks

 

Because it idles rough and brakes are weak, It is most likely the brake booster vacuum line. The check valve is freezing stuck open with no vacuum on it and when started it is not seating to prevent lack of vacuum. The inability to hold vacuum will cause the engine to run rough and the brakes not to work properly.

 

If this brake booster hose is bad, would it only act up when the temperatures outside are really cold outside? Is this something that I can check out to see if it is bad? Thanks for the input it is greatly appreciated...

 

Yes, because the brake booster line is rigid, when it is weak, leaking, old it contracts when cold and leaks air. To test on a regular warm day, you can spray starter fluid or brake cleaner at connections to booster, both sides of bulb in middle and top of manifold and your car will change r.p.m.'s. But if it only happens when cold and is caused only by contraction, it would be hard to duplicate. If replacing make sure you look at descriptions on this forum for how the line is removed (particularly from manifold).

 

I need to also replace my brake booster hose and need to know the procedure and "tricks". From a previous post it sounds like you have to push down on the "brass sleeve" on the intake to remove the hose? Any tricks to removing it from the brake booster or just pry it off with a screwdriver. Any guidance would be appreciated.


Thanks,
Ken

 

There should be a black plastic collar around the tube. That is press against the intake manifold and the tube pulled out while it is pressed. The end on the booster will just pull out with its O-Ring seal.

 

C2S17552 - BRAKE BOOSTER VACUUM HOSE WITH CHECK VALVE

I prefer to never pry anything with a screwdriver, but that's me. I use various pliers for a good grip. Yes, you push down on the ring before trying to pull the tube out of the manifold. Think of it kind of like a Chinese finger trap = pull on it and it tightens.