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Brake pedal return springs..
bigandy - 21/11/06 at 02:17 PM

Afternoon all,

I've just been checking the braking system on my car before I bite the bullet and fill it up with fluid, and I've noticed that I haven't fitted a pedal return spring on the brake or clutch pedals (both wilwood remote rervoir master cylinders, with a bias bar on the brakes).

Is it generally recommended to fit some kind of return spring on these pedals, or is it acceptable to rely on hydraulic pressure, or the master cylinders to retunr the pedal to the top of its travel?

My gut feeling is that it would be a wise idea to fit a return spring, if only to minimise any residual pressure in the system due to friction and the pedal weight.

Which brings me on to my next question, what sort of force would you want to return the cylinder actuation arm (so I can work out the spring rate required)?

Finally, does anyone know a good source of extension springs, roughly 50-55mm long no load, and extending a maximum of about 12.5mm. The end can be a simple hook, or a loop.

Cheers
Andy


mookaloid - 21/11/06 at 02:26 PM

Mine has no return springs and it is fine


DIY Si - 21/11/06 at 02:31 PM

None here either.


Big Daz - 21/11/06 at 03:27 PM

I have fitted one to the throttle pedal just to help the cable and take up any slack, brake - none fitted and clutch is a solid bar arrangement so no spring needed there either

Daz


andrews_45 - 21/11/06 at 04:45 PM

nah, you wont need one on the brake pedal


JB - 21/11/06 at 05:31 PM

None here either on the clutch and brake.

John


02GF74 - 22/11/06 at 08:58 AM

the springs within the master should be strong enough to push the piston fully out; there should be a bit of slack 1 or 2 mm before the pedal acts on the rod; if not, if you have that then no need for spring but ofcourse fitting one isn't going to hurt.


Peteff - 22/11/06 at 11:45 AM

I have a modified Mk2 Escort pedal setup and installed the spring in it's original location on the clutch and brake pedal. I have used the brake without the spring installed and it doesn't return as quickly so I think it's better with one fitted. I used the one that was on the pedal but the spring rate shouldn't be critical as long as it does the job.
Top mount pedals.
Top mount pedals.


[Edited on 22/11/06 by Peteff]


Chazzy - 23/11/06 at 11:01 PM

the pressure in the brake system will return the pedal. if the pressure is enogh to push small pads onto the discs/shoes and stop a car, it will be enough to return the pedal to upright. remember it pushes back with the same force that YOU apply to it. (ignoring small resultant force to accelerate the movement of the pedal for the pedants out there ;-) )
ditto with clutch pedal, how strong are the clutch plate springs?

you might want to put a stop on the return movement so the pedals don't fall down (if bottom hinged)

my accelerator pedal has an extra return spring in case the one on the carbs breaks.

Chas


Peteff - 24/11/06 at 12:34 AM

Why does it? The only thing that pushes it back is the spring in the master cylinder and the shoe springs and caliper seals after the fluid is back to it's normal state. Every action has an opposite and equal reaction doesn't apply as the reaction is the force applied to the brake disks and drums.


C10CoryM - 24/11/06 at 03:27 AM

I would highly recommend adding brake return spring to the pedal. There has been a couple times where I have lost brake pressure, and had to pump like crazy to get stopped. If there had been no pedal return spring I would have not been able to pump it up enough to get stopped. Boil the brake fluid at the track or blow a seal and you NEED that spring.
Cheers.