[Spridgets] Master Cyl Cap ?

Kirk Hargreaves khargreaves2 at gmail.com
Fri Nov 20 14:02:14 MST 2009


Peter,

Yeah, now I do recall seeing the diaphragm inside the motorcycle caps. .
thanks for dealing with my ignorance!   Kirk

On Fri, Nov 20, 2009 at 12:28 PM, Peter Caldwell <peter at nosimport.com>wrote:

> ALL brake and clutch master cylinders must vent. Period. Some manufacturers
> will have a diaphragm inside the reservoir to prevent sloshing out of the
> vent hole, but is not sealed.   Think of your thumb over a soda straw.
>
> Peter C
> ==
> At 02:17 PM 11/20/2009, Kirk Hargreaves wrote:
>
>> Bought a new Master Cyl cap from Moss for my 1275 '59.
>>
>> With the new one I can see the small vent holes.  . two of them.
>>
>> They are very tiny.  My last cap was wheezing misty brake fluid . . the
>> harder I would pump. .  it appeared that the more pressure would be
>> released
>> from the system.  It actually formed a crack along the indent surface of
>> the
>> top. .  a crack that was nearly an inch long.  The thing was disallowing
>> my
>> MC to hold pressure. .  at least it appears as such.  . because I can now
>> get pressure back to my brakes (even with the small leak on one of the
>> rear
>> wheels that I still need to fix).
>>
>> I was a disbeliever (at first) that these caps even vented at all.
>> Certainly the brake cyls on my motorcycle are not as such. .  they are
>> sealed.
>>
>> A couple of questions while I continue to kick this subject to death
>> (thanks
>> for your patience).
>>
>> I also bought the cork ring that goes inside of the cap. .  another 5
>> bucks
>> from "the low price leader" Moss Motors. . .
>>
>> I use to not have this cork gasket (ring) in my old cap when the brake
>> system was working. .  is this super important.  . the cork gasket, ring
>> that goes inside?
>>
>> Also. .  do the very tiny vent holes vent in both directions. .  or are
>> they
>> designed to vent in one direction only, such as when the M. Cyl needs to
>> replenish it's air supply. .  back feed?
>>
>> Frank told me that he drilled a small hole in the top of one of his caps.
>> .
>> as such replacing the small hole that they come with.  . so I guess that
>> answers my question . . but they might have been originally designed to be
>> more of a one way vent, even though they can work both ways?  Ok, it is a
>> dumb question. .  but I guess I am still surprised that they vent at all
>> considering other equivalents.
>>
>> I will take my answer off the air.  .
>>
>> And, thanks to all for ALL OF THE GREAT HELP that all of you have been to
>> guys like me.  Without your help. .  I would have spent many unnecessary
>> hours repairing and modifying my car through the years.
>>
>> Kirk
>> 59 Bugeye. .  running around a little over 80 HP (about the max that the
>> rear end can take - from what I have heard)?
>> _______________________________________________
>> Support Team.Net  http://www.team.net/donate.html
>>
>> You are subscribed as peter at nosimport.com
>>
>> http://www.team.net/archive
>>
>> http://autox.team.net/mailman/listinfo/spridgets
>>
>>
>> No virus found in this incoming message.
>> Checked by AVG - www.avg.com
>> Version: 9.0.709 / Virus Database: 270.14.74/2515 - Release Date: 11/20/09
>> 02:02:00


More information about the Spridgets mailing list