Hi, I got recently an issue on my 1988 328GTB. After about 30 minutes drive, the red light of brake system issue has become RED. I could not feel any issue with braking, but I stopped to check if there was some leakage or so. Did not see anything under the car so I decided to turn back to house by security, driving a low/medium speed. After about 10 minutes (red light was remaining RED), I almost lost all braking power... As if only my foot pressure on the pedal was the only putting pressure in the hydraulic system. So, I am thinking of a brake vaccum servo issue ..? but a dealer told me that if red light is on, problem is linked with ABS hydraulic system. What do you think ? thanks !
System info in this threaded: https://www.ferrarichat.com/forum/threads/328-abs-brake-system-info.539888/
There are two red warning lights on my Mondial 3.2 which has the same Teves MkII ABS system as yours. One is the brake failure warning light, the other is the ABS warning light. The brake failure light will go on when the fluid is low, or the servo hydraulic pressure is low. With the car off, turn the key to the start position. The ABS warning light will come on for a few seconds, as it self checks for faults. If no faults, it goes off. If it stays on there is an electrical fault in the ABS system. With the same key sequence, the brake failure light may go on for as long as 30 seconds, as the accumulator is charged, depends how the long the car has sat before you do this. If it stays on, your fluid pressure is not sufficient. Probably a failed accumulator as a first guess. When the accumulator fails, the car will brake about 4 to 6 times before all pressure is gone. Then you loose the braking, although the front brakes will still operate but with no servo assistance. Sounds like what you experienced. You would really need to stand on the pedal to get it to stop if this is the case, but there should still be some brake action. This is not really somethign a handyman should work on, the accumulator pressures can be very high. What a tech would do is the following. There is a port at the high presssure line at the accumulator where you can attach a pressure guage to pressure test the system. You pump the system up with the ignition off 25 imes to unload the pressure. Attach the guage, operate the electric pump briefly to empty the pressure guage, the pump the pedal again to unload the pressure. Set a stop watch an measure as per the attached...there are five problems you can measure for. This is an extract from the Ferrari Teves II ABS Technical Manual. There plenty of electrical error codes and measurement procedures, but that is for the ABS unit itself. The ABS can fail, but will be independent of the brakes themselves failing. Pretty sure that's not what is going on for you. I am not sure if an accumulator can be replaced separately from the master cylinder itself. I suspect as it is external (some modern units have the unit all as one item) a specialty rebuilder can replace it. A full rebuilt unit might be available here...http://www.invasionautoproducts.com/98feabspu70.html You would have to do more research, but this may be the replacement accumulator here...https://www.ferraripartsexchange.com/products/abs-accumulator-pump-p002 Anyways, hope that takes a bit of the mystery out of what the problem could be. I presume you have first checked the fluid level! There is a max min level on the tank.
With the Teves MkII braking system, the brakes should have normal braking power even if the ABS portion of the system is malfunctioning. The flash codes are used to diagnose just the ABS portion of the system (such as a defective wheel speed sensor). If you lose all braking power there is a fault with the pressure portion of the system which consists of relays, a pressure switch a pump an accumulator and a brake booster/master. The pump is supposed to recharge the accumulator once the pressure in the accumulator drops below a certain pressure. When the accumulator goes bad the pump is constantly trying to recharge the accumulator after each brake pedal application. From the symptoms described, loss of all braking power, I would say that there is a problem that is causing the pump not to run: loss of electrical power (relays), defective pressure switch, etc. Someone who has knowledge with the Teves system needs to properly diagnose the cause of the problem. There is much information on the system: Ferrari, Ford, Jaguar and Alfa Romeo all made service manuals for the system.
There are some things you can do at home. 1. without turning on the car, turn the key to On position, applied the brakes multiple times to bleed off any pressure in the system, listen to hear if the ABS hydraulic pump is turned on. a. if it comes on for 30 seconds and stops, then at least the pump is working. b. if it comes on but never stops, then the pump is not building pressure or the pressure switch is bad, You need a new pump c. if it does not come on at all, then apply 12v directly to the pump to isolate where the problem is. If it runs with 12V applied, then the problem is in the relay circuit controlling the pump. Find a wiring diagram and start probing. If it does not run, even with 12V applies to it, you need a new pump.
I would add a d: to the above list If the pump runs for a few seconds then stops as full pressure is reached too early, the accumulator has internally failed and is full of brake fluid.
I am not familiar with this particular ABS system, nor the particulars in addressing problems with it. But as mentioned above, approach home repair with caution. An ABS system can have pressures in the 3,000 psi range - that's enough to make brake fluid pierce your skin and send you to the hospital. It's not like a non-ABS system, where you can just disconnect anything you see and the worst that happens is air getting into the lines.
Been a while since I have seen an issue with these, they are for the most part a built proof system. That said, I believe the system in the 328 is based off of the Ford unit that was found in the Thunderbird super coupe of the 90's.
