Thread on club scuderia for a 348 says brake light came on and 5 minutes later toral brake failure. Others say it also happened...one says blown relay in passenger footwell Is this possible? Total brake failure....gulp?????
It was my 348 he is referring to. If I recall correctly it was just a case of a fuse or relay blowing. Bloody scary though.
Isn't safety default no ABS manual braking like pre-ABS era. You can even disable the ABS and have perfect non-abs braking with good proportioning. I have done that while racing the 348 and considered total ABS removal. How can a blown fuse or relay cause total brake failure?
Yeah, I thought the ABS was there as an add on to the brake system and it's failure doesn't affect the standard braking capabilities.
"Total" brake failure sounds highly unlikely from a fuse problem. The brakes themselves are still mechanical. Kai
LOss of proper operation on one sensor can feel like "total brake failure", but that's an exaggeration of what happens. It feels like it lets go at a very slow speed.
It wasnt stated what the actual brake failure mode was ie: pedal to the floor or hard pedal I can certainly state that a "hard pedal" situation was basically total brake failure this happed to me I was literally standing on my brake to slow down and used my hand brake as that was really all i had I was told it could be a sticky relay that overheated the ABS motor but it has never happened again I hope hope it never does, I certainly dont need my seat dyed darker!
Boost failure. Not total brake failure. There are a few different things that can cause this. Op needs to be more specific.
This is very misleading Are you saying that a blown fuse/relay resulted in you having no brakes in your 348? I suggest you think about what you post before posting Scary stuff...be pinpoint specific or do not post on such an important subject
It can even happen in moderns. I recall a few years back my father had proper total brake failure, in what was at the time a brand new 55 plate E class. Merc. It resulted in the car having to go back to HQ in Germany (MB UK couldn't diagnose it) , afterwhich out came a mod that was additional ground wire to the brake electronics. After nearly a full year of loan cars from MB dealer he got another brand new E class (with the mod wire clearly on show!). My father worked for UK Government new vehicle type approval (VCA) at the time, if that weren't the case I wonder how much attention he would have got from MB or if he'd have got a replacement new car?
Needs to be pinpoint specific. Drivers driving at high speeds need to know if indeed a blown fuse/relay causes total brake failure
Start car and leave my garage. Brake warning light comes on. I carry on driving the 400 metres to the tyre place to have a nail removed from my tyre. Start car again and brake warning light is still on. Drive it 30 feet and total brake failure. Can't remember if it was hard pedal or soft mushy pedal. Coast to the side of the road and use hand brake to stop the car. Was doing around 20mph Call Ferrari assist recovery. 90 minutes later car picked up and sent to Ferrari main dealer. Few days later went to pick up the car. Told that it was an electrical issue and fuse or relay in the passenger footwell fusebook had blown. They used a wire to by pass the relay. Did consider buying a new relay but never got around to it. I may have misunderstood the fault they told me, but that's what I recall. There was no big mechanical issue with the brakes. That I am sure of as the bill was very small (in Ferrari terms). I had a look at the 348 manual and there doesn't seem to be a relay for the brakes there so not sure myself now either. Will take a pic of the relay tomorrow and post up. EDIT: A few days earlier I did have the Clutch Release Bearing changed. That may have initiated the fault perhaps?
Brakes are hydraulic. No pump, just foot pressure. Booster makes braking easier. But if it craps out, then push harder. What could fail electrically that would cause the brakes to fail? Nothing I can think of. Break a line or fitting and yea, pedal to the floor. Master cylinder dies, yea - pedal to the floor. Not that big of a deal. I had a total brake failure at 70 mph on an exit ramp in my TR8. Line snapped on R/H front caliper. Down shift, e-brake and stop. In fact I drove it 20 miles home that way. If an e-brake isn't maintained right, then yea, brake failure is an issue. But that's not the cars fault.
Agree..boost failure will give a really hard pedal. But if you stand on it, the car will stop. Total brake failure is extremely rare.
The other possibility is dragging brake pad, fluid boils, pedal to the metal, soil your seat, Caliper gets fixed. But if the bill was reasonable, then this wasn't the condition.
With the 348 brake boost system, a total failure is possible if the high pressure hose from the hydraulic pump to the pipe going to the master brake cylinder fails. The pump will then pump all the reservoir fluid into the boot. But, even then, the failure will not be immediate - you will get the warning light and there will be still enough fluid in the master cylinder, and the high pressure pipe leading to it, for a few brakings (with very hard pedal). I have heard a story about a Range Rover (same brake boost system) which lost the brakes completely due to failed high pressure hose and bashed through the barrier at a toll plaza. But the driver probably ignored the warning lights. Fluid boiling, as suggested, is another danger. This is why replacing the brake fluid completely every 1 to 2 years (I do it every year in humid Malaysian climate) is required. Brake fluid absorbs moisture which dramatically reduces the boiling point of the fluid even down to half of that of fresh fluid. It does not take much braking to boil neglected fluid.
