12 replies to this topic

[hallett]

Hi guys, just after a bit of advice, i have just bought some 4 pot front calipers for a 7.5" cooper s set up and im sure i remember reading somewhere to install 1/2" rear wheel cylinders for best brake balance. One of mine is seized so im looking to replace both anyway and just completely overall the complete braking system. Was this 1/2" cylinder just one persons opinion or something i should definitely do? Thanks,

Daniel

[Gr4h4m]

They gave me a much better pedal with my fiesta calipers up front, with a single bean can M/C and the stepped yellow tag M/C.

They improved the feel as the pedal it right there. I have read a few times on forums that you get a slightly longer pedal with four pots, I wouldn't know because I have never run them or driven a mini with 4pots fitted.

[hallett]

I dont know what M/C i have but at the moment the brakes are standard for a '93 with a servo, i might just order the cylinders and if i dont like it then change for some a larger size, there are plenty to choose from and there cheap enough, i havent put the 4 pots on yet so dont know what difference they will make to pedal feel or travel!.

 

Daniel

[grumpy dad]

Hi 

hope this helps

the bigger the wheel cylinder

the more pedal travel you will have 

and the harder you will have to push

don't forget you want about 80% of the braking at the front

[Gremlin]

Hi 
hope this helps
the bigger the wheel cylinder
the more pedal travel you will have 
and the harder you will have to push
don't forget you want about 80% of the braking at the front

The harder you will have to push?

[petey81]

Hi 
hope this helps
the bigger the wheel cylinder
the more pedal travel you will have 
and the harder you will have to push
don't forget you want about 80% of the braking at the front

???????

[F1L8EY]

i only know simple hydraulics. pressure is equal to force x area... with 4 pots (assuming they make a collective lager piston surface area than 2 pots) surly should decrease the amount of force needed to apply the same amount of px ?? 

 

however due to the increased volume of fluid required the pedal travel would be further (more fluid displaced)

[grumpy dad]

The harder you will have to push?  the brake pedal

[Rog46]

Hi 
hope this helps
the bigger the wheel cylinder
the more pedal travel you will have 
and the harder you will have to push
don't forget you want about 80% of the braking at the front

Bigger wheel cylinders = more travel on the master cylinder but LESS force needed!

[hallett]

So by fitting the smaller 1/2" cylinders it should offset the longer travel produced by the 4 pots?! I think the reason I read about was to fit the smaller cylinders to stop the rear wheels locking up before the front wheels and therefore giving better and more stable braking, does anyone have experiance of this?

 

Daniel

[Rog46]

Hi 
hope this helps
the bigger the wheel cylinder
the more pedal travel you will have 
and the harder you will have to push
don't forget you want about 80% of the braking at the front

Bigger wheel cylinders = more travel on the master cylinder but LESS force needed!

That's to get the same braking force on the REAR wheels! In practice 80% of braking is on the front so you just push the same and get slightly less braking on the rear!

[Gremlin]

i only know simple hydraulics. pressure is equal to force x area... with 4 pots (assuming they make a collective lager piston surface area than 2 pots) surly should decrease the amount of force needed to apply the same amount of px ?? 
 
however due to the increased volume of fluid required the pedal travel would be further (more fluid displaced)

Exactly

[F1L8EY]

have you got the dimensions for the 4 x front pistons and the 2 x rear pistons ?? and the slave and masters i can do maths ;)