Hi to all ! For the last couple of months I've been experiencing something strange with my 360. Whenever my car stands for 10-14 days without moving, when I start the car for the first 3 minutes or so there is NO POWER ASSISTANCE for the brakes !!! As I move the car at 2-3 mph it requires huge effort to depress the brake pedal that is very stiff and does little to stop the car. After a while it becomes completely normal. When I use the car more frequently this issue never occurs. Any idea what might have caused this problem. In the past when I left my car even for 1 month without moving it there was no such issue. Thanks for your replies !
When was the last time you had your brake fluid flushed and changed? I know a fellow owner who had the same symptom. Was not the booster but the fluid. Flushed and fine since.
Vacuum valves are on the front of the engine air intake. I'd check these for a leak and for a leak at the brake booster...
Thanks for your replies ! I changed the brake fluids and bleed the system to remove any air (from the valve inside the luggage compartment) while I changed the brake pads 9 months ago... The problem existed before and after the brake fluid change... It occurs only if car has been sitting for more than 10-14 days... If there is indeed a leak you are suggesting that it is an air leak or a brake fluid leak ?
Air leak. What happens is engine vacuum sucks the air out of the hose from the back of the air intake on the engine to the brake booster. This vacuum is what "helps" the brake booster make it easier for you to press down and actuate the brakes. There are one way valves that "hold" the vacuum in the line. I.e. the engine sucks out the air in this thick tube and when it stops running, the air doesn't enter back into the line because the one way valves prevent it. If there is a soo slight leak at the hose, the vacuum will slowly leak after the engine is shut off. Or, if one of the valves is leaking slightly, the vacuum leaks back once the engine is shut down. Depeding on the year try checking out #24, at #2, at #7 and if an earlier 99 car like mine at #15. At least rule this out before going to other venues. To me it seems to explain most of what you're experiencing. Image Unavailable, Please Login
This explanation makes a lot of sense ! As the car sits I assume that the air tank also loses its vacuum completely and that's why it takes a while to build up vacuum and start providing power assistance on the brakes... I will check it out with my mechanic... Do you think it is something that should be addressed urgently or can it wait until December that I've scheduled service ?
I can't make that call for you. Let it build vacuum before you drive it. Just be aware that in the event of a failaure you're going to hav to stand on the pedal.
I’m having a similar issue - but not quite the same. Just bought the 360 a month or so ago. I’m a Ferrari cherry the break peddle feels normal but I’m not getting the grip I expect. Thinking it could be glazed rotors? Pads look good (maybe a cheap pad from the original owner? searched this topic to see if it could be vacuum / boost related. going to drive it again this am for a feel.
Urgent. Early 360 brake vacuum supply was a stupid design. It has 2 poorly designed vacuum valves and if either fail it does as you describe. The CS has a much better system with a single inexpensive valve located near the booster. No modification required, just get the valve, cut the hose near the booster and install it with 2 hose clamps.
Why? If you understand basic physics it makes no difference to anyone or anything if they are there or not.
Well, since we are visiting this topic due to a potential FAILURE of one of the admittedly poor engineered check valves, I could imagine that a stuck valve that may have some effect on the overall functionality of the vacuum system as their sole purpose is to act allow one way air flow....but what do I know? I'm just like everyone else here, stupid but unaware until Brian lets us know. Thanks for your help. What would we do without you?
I'm getting ready to do this but, for the sake of originality, I can't bring myself to cut the line which means I need to buy the second hose piece. I have looked all over and it is unavailable. Will any standard vacuum booster line work or is there something special about the 360 set up? Its a bosch booster so I am assuming its basically standard but I am just making sure.
I would not worry about originality on a hose no one but possibly some future mechanic will ever see. I have never seen a Bosch brake booster so doubt that but yes, it will be a common hose.
Ok, thanks about the hose. As per the booster, did I use the wrong terminology? Should I have said servo? attached are two images of the Bosch part I was referring to. Image Unavailable, Please Login Image Unavailable, Please Login
Cool, maybe its just on the 1999's. This is not off my car but mine is also from 99 but earlier. I have never seen one on any other 360 so I only have a sample size of 2.
Update. So I actually did the update suggested by just cutting the vacuum line near the booster and sticking a CS vacuum valve in that location. I did it a month ago but just got to drive my car for the first time yesterday. The difference is obvious and this solution with out a doubt fixed a problem. The best way I can describe it is that the brakes are now predictable in their operation when they were not before as well as much much more effective. Before the fix I was thinking about upgrading the brakes but now with this fix I have no interest in doing that, the stock brakes are more than fine for road use. So if you have the old style vacuum lines I would go ahead and give this a try. Easy,cheap fix and worth while with all the down time we have recently.
