My Fiat 850 project had two curiosities that someone on the Fiat site said were "Safety brakers" but no one know what the are suppose to do. Any ideas what these are? There is one on each side of the front brake circuits. Now is the time to remove them as I am replacing the master cylinder as a matter of precaution given this thing is 56 years old and the front brakes calipers were locked so the brakes have been worked on for some time.
Probably limit brake pressure so you don't lock up the lightly loaded front brakes? Classic Minis have something similar on the back (front drive car)
They look like a hydraulic fuse. If you were to have a brake line failure it would prevent all the fluid leaving the car so you would still have the other front brake.
I'm pretty sure MiniDave is correct. These things were marketed as "add ABS to your classic". It's just a spring-loaded piston and cylinder that gives the fluid a place to go (other than the caliper) when that circuit reaches whatever pressure it takes to overcome the spring. So dumb.
This car has a lot of vintage speed parts on it, lowered, koni shocks, 8 pound mag wheels, engine upgrades, roll bar, so don't know all the history but that makes sense. I am rebuilding the entire braking system, so new master, calipers, rear cylinders, shoes, pads and rotors. So if these things were grafted in, might make sense to replace the front hard lines and simplify the system.
In reply to triumph7 :
That was my guess as well.
Brake force limiters, seems like a good idea, just size the spring to your current coefficient of friction. Does it have a knob on the back side for on the fly adjustments? So, good pedal feel until you reach the limit then squish, super confidence inspiring, never lockup a tire again, just push for what you get. The motor probably works the same way, accelerator pedal just gets mashed to the floor and you get what you get and just wait.
AngryCorvair (Forum Supporter) said:I'm pretty sure MiniDave is correct. These things were marketed as "add ABS to your classic". It's just a spring-loaded piston and cylinder that gives the fluid a place to go (other than the caliper) when that circuit reaches whatever pressure it takes to overcome the spring. So dumb.
Learned something new again. I assume that ABS in this case stands for "abysmal braking system"?
Yeah these seem to be a bad idea. I have not read that 850 spiders have brake issues, unlike my Lancia Scorpion that are well known for having brake bias issues. I'll order a new set of lines and simply the system.
AngryCorvair (Forum Supporter) said:I'm pretty sure MiniDave is correct. These things were marketed as "add ABS to your classic". It's just a spring-loaded piston and cylinder that gives the fluid a place to go (other than the caliper) when that circuit reaches whatever pressure it takes to overcome the spring. So dumb.
But they were also used on motorcycles and airplanes!!
I don't see why that device was necessary. I see a lot of compression fittings on the brake lines, which is instant condemnation in my book. Blowing a brake line apart will also prevent lockup.
In reply to Pete. (l33t FS) :
I was just trying to figure out if those were compression fittings or not. Yikes.
When I worked at O'Reilly there was at least a customer a week asking why I wouldn't sell them compression fittings and brake hard lines. No sir, I'm not doing it.
Yes, the closer I look at it, definitely hardware store fittings were used to install these devices, this work had to have happened many years ago. I guess perhaps the driver was having lockup issues in his autocross runs so did this great "modification" to solve the problem. I wonder how many people drove around having no idea this crap was on the car, the previous owner had the car in SC and drive it as his summer fun car.
Found out the history https://www.apexspeed.com/forums/showthread.php?51874-mystery-part-(anti-lock-brakes-on-a-Formula-Ford-)
Apparently they were invented by Bob Booth, who was a racer and were popular in the 70's. Apparently don't do much of anything and disappeared off market a few years later. They will now "disappear" off of my old 850!
Pete. (l33t FS) said:AngryCorvair (Forum Supporter) said:I'm pretty sure MiniDave is correct. These things were marketed as "add ABS to your classic". It's just a spring-loaded piston and cylinder that gives the fluid a place to go (other than the caliper) when that circuit reaches whatever pressure it takes to overcome the spring. So dumb.
But they were also used on motorcycles and airplanes!!
i remember that from the advertisements back in the day. Unfortunately my google-fu is failing me and my searches for info on these devices is coming up empty.
I don't see why that device was necessary. I see a lot of compression fittings on the brake lines, which is instant condemnation in my book. Blowing a brake line apart will also prevent lockup.
Yeah, I forgot to fitting-shame the installation above. dherr will make it right.
In reply to dherr (Forum Supporter) :
They were sold by JC Whitney in the 80s and possibly into the 90s. That's where I remembered the bit about where else they were used.
I assumed that they weren't necessarily a pressure limiter, but a pressure damper, to prevent a sudden spike from a ham-fisted driver causing lockup. Either way, they seemed like a bodge.
I assumed that they weren't necessarily a pressure limiter, but a pressure damper, to prevent a sudden spike from a ham-fisted driver causing lockup. Either way, they seemed like a bodge.
This is exactly what they are supposed to do. They were very popular on motorcycles.
Pete. (l33t FS) said:In reply to dherr (Forum Supporter) :
They were sold by JC Whitney in the 80s and possibly into the 90s. That's where I remembered the bit about where else they were used.
Yes, I remember seeing them in the JC Whitney catalog.
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