| Author |
Message |
'75 308 GT4 (Peter)
| | Posted on Tuesday, March 13, 2001 - 3:04 am: | |
Try this site:
http://www.whitepost.com
White Post Restorations. They rebuild brake parts. See their ad in Forza. |
Steve (Steve)
| | Posted on Monday, March 12, 2001 - 8:20 pm: | |
I'm working on the same problem with my 77 308 . If you go under the car in the front there is an acccess panel that when you remove it you see 2 brake valves. One is the pressure valve for the rear brakes and the other is the bias valve that has the switch in it that turn on the light if you loose brake pressure on the front or rear circuits.I am looking for these 2 valves or for someplace to get them rebuilt. I had a failure with a rear caliper locking up and boiling the fluid which caused the bias valve to shift. Well I guess after 24 years the valve would not shift back after I bled the brakes. Also the unit I have doesn't let you remove the switch from the outside and it is a sealed unit. Any help or suggestions welcomed. Steve |
'75 308 GT4 (Peter)
| | Posted on Monday, February 12, 2001 - 12:48 am: | |
I know my GT4 is a world apart when compared to the 328, but the way my brake light is triggered is by a switch acting on a two-way piston. Under normal instances the piston is stationary, because on either side of it is the individual circuits for the brake lines, so when pressure is applied, it is applied equally balancing this piston. When a pressure drop occurs (broken hose or pipe) in one of those lines, the other line under pressure forces the piston to that side. That piston has a tapered profile, this taper forces the switch and thus the light goes on the dash.
From what Craig described, if you had an air bubble, yes the switch would be triggered but when fluid returns to that line, the pressure is now equal and the piston is now stationary.
I know the feeling of air bubbles in brakes, scares the living ---- out of you!!! |
Rob Lay (Rob328gts)
| | Posted on Saturday, February 10, 2001 - 10:21 pm: | |
Thanks Craig, if it's not the brake fluid or pads, I'll have them look at it next time. |
CraigFL
| | Posted on Saturday, February 10, 2001 - 7:11 pm: | |
Rob,
The schematic shows that three items can cause light(warning light 50) to go on:
1. Brake fluid reservoir - low level
2. Front pad wear
3. Imbalance of front/rear pressure
I would check to see if the brake fluid level is OK first(and the connection on the reservoir sensing switch). If it's low, add fluid and check for leaks. If no leaks, probably hasn't been filled in a while and the pads have worn enough to need more fluid.
If that isn't it, you may need new pads in the front-- pads less than 3mm thick will trip the light.
If pads OK, you may have leak or air in the system causing the pressure imbalance. This will require more work. |
Rob Lay (Rob328gts)
| | Posted on Saturday, February 10, 2001 - 6:42 pm: | |
When the 328 was still a little cold, whenever I got on the brakes the "brake failure" light would come on. It went away after awhile and I never had any problems with the brakes. Can you help me understand what sets this warning light on? Thanks. |
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