Hi,

Why some master cylindres have bigger tanks for the fore brakes than for the rear brakes and another have 2 similar tanks?

What different are there between master cylindres for disc brakes and drum brakes?

... and between power and manual brakes master cylinders?

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... de los que tengo, este es el que más gusta a mis hermanos:

The MCs with similar reservoir chamber capacities are used with all drum brake systems and more recently 4-wheel disk systems. Those with a small front chamber and large rear chamber are for systems with front disk brakes and rear drums. Note that the front chamber supplies fluid to the rear brakes and vice versa.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

I am afraid I`ve got a problem.

I didn´t know it and I have installed a new MC with the same capacity on both chambers in my car ... and my car has front discs and rear drums.

can I have problems with my brakes?

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... de los que tengo, este es el que más gusta a mis hermanos:

Disc brakes require a larger volume of fluid to operate over the life of the pads, because as the pads wear, the fluid level in the master cylinder will drop (since more fluid resides in the calipers as the pads wear and the pistons' "home" position is closer and closer to the disc rotor). That's why disc brake master cylinders have a larger reservoir for the disc brake portion of the system. In addition, while a drum brake master cylinder can operate disc brakes OK, there are often differences in calibration that make the disc brake master cylinder the better choice for a disc brake system.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Does the disc brake master also have a residual check valve inside? And can our Spanish friend also get the brake pressure he needs by installing an adjustable proportioning valve to redirect more pressure to the fronts. Or am I all wet and the smaller chamber manual MC will simply not have the fluid capacity to keep up with the calipers? It sounds to me like Erivaj already has this unit in place and is looking for a solution that doesn't involve buying a new MC.

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Just check the fluid level in the cylinder more often..................

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

No. Residual pressure valves were installed on '67-'72 drum brake master cylinder outputs (and the rear drum brake outputs of '67-'72 disc/drum masters).
No.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Yes, I have this unit with two similar chambers in place, and after a couple of days using it, it is leaking some brake fluid just in between the power brake and the MC. The rear chamber level is ok, but the front chamber level is decreasing slowly.

I don´t know if the new MC is leaking because it was not Ok, or otherwise the leakage is caused because by the different volume that need the front disc and rear drum brakes.

In a MC with bigger chamber for the front disc, when you push the brakes the stroke of the MC is the same on both chambers ... then the volume for front disc and rear drums are the same, aren´t they?


Of course, this is my first solution to avoid bigger problems.

I would like to know if I can stop the leakage of the MC I have adjusting something or similar.

_________________
... de los que tengo, este es el que más gusta a mis hermanos:

how bout from power to manuals? i ask cuz i want to swap to manual disc.
would my power mc fit the manual pushrod? and would the manual mc bolt to a booster?

If the front chamber is losing fluid it means that something is leaking in the rear (drum) brake circuit. Also, if you're seeing fluid at the rear of the master cylinder then you have a leak and the MC must be either rebuilt or replaced. At this point I would strongly recommend replacement with a master designed for used with front disk brakes.

A power brake master cylinder will work with manual brakes and will work perfectly well but there are a couple of possible issues with it. First the diameter of the piston may be different which will affect the firmness and pedal travel of the braking system; that is largely a matter of preference. Second, a power brake MC may not be designed to retain the pushrod. Under certain conditions the rod could come free from the master cylinder and you would have no brakes at all.

_________________
David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.