Shovelhead A place to talk about Shovelheads.

Front brake master cylinder ?

Thread Tools
 
Search this Thread
 
Old Mar 26, 2013 | 04:28 PM
  #1  
78lowshovel's Avatar
78lowshovel
Thread Starter
|
Advanced
Joined: Oct 2012
Posts: 81
Likes: 1
From: Seattle
Default Front brake master cylinder ?

So i have a little vent hole in the middle my front master cylinder. Does this serve a puprose other than to allow brake fluid to drip onto my gas tank? I would like to plug it or replace the master cylinder cover.... Thoughts?
 
Reply
Old Mar 26, 2013 | 07:02 PM
  #2  
TwiZted Biker's Avatar
TwiZted Biker
Club Member
15 Year Member
Loved
Community Favorite
Top Answer: 10
Joined: Mar 2009
Posts: 66,128
Likes: 51,461
From: Niles Canyon Ca.
Default

It's a vent port and DO NOT BLOCK OR SEAL it off , if it's leaking you need a a new cover gasket and maybe a cover too . Seen a bunch of those warp for whatever reason , pull the cover off and lay it on something flat like glass and check the flatness and that has a thin paper gasket with what looks a condom sandwiched in there , easy to tear and leak it will .
 
Reply
Old Mar 26, 2013 | 09:20 PM
  #3  
78lowshovel's Avatar
78lowshovel
Thread Starter
|
Advanced
Joined: Oct 2012
Posts: 81
Likes: 1
From: Seattle
Default

Originally Posted by TwiZted Biker
It's a vent port and DO NOT BLOCK OR SEAL it off , if it's leaking you need a a new cover gasket and maybe a cover too . Seen a bunch of those warp for whatever reason , pull the cover off and lay it on something flat like glass and check the flatness and that has a thin paper gasket with what looks a condom sandwiched in there , easy to tear and leak it will .
That's what I figured. Thanks.
 
Reply
Old Mar 27, 2013 | 02:16 PM
  #4  
carlgrover's Avatar
carlgrover
Seasoned HDF Member
15 Year Member
Liked
Loved
Top Answer: 1
Joined: Oct 2007
Posts: 8,852
Likes: 2,494
From: Decatur, Alabama
Default

You can buy those gaskets in packs of 6.


Carl
 
Reply
Old Nov 28, 2014 | 12:38 PM
  #5  
72_shovel's Avatar
72_shovel
Cruiser
Joined: Jun 2014
Posts: 102
Likes: 6
From: Minnesota
Default

Bumping an old thread here... but I'm having the same problem with mine. Have replaced the gasket three times, even tried a brand new cap. Still leaks, still will not hold pressure. I'm thinking I need a whole new master cylinder... any tips/thoughts?
 
Reply
Old Nov 28, 2014 | 01:59 PM
  #6  
johnjzjz's Avatar
johnjzjz
Seasoned HDF Member
15 Year Member
Top Answer: 3
Joined: Nov 2006
Posts: 12,878
Likes: 5,449
From: la la land jerzey
Default

Originally Posted by 72_shovel
Bumping an old thread here... but I'm having the same problem with mine. Have replaced the gasket three times, even tried a brand new cap. Still leaks, still will not hold pressure. I'm thinking I need a whole new master cylinder... any tips/thoughts?
yep its internal bypasing the fluid and if it is full to the top it will come out someplace - just get another one - they are only china today and its 50 50 if you get a good one

you could try a kit but we are talking about a master that is probly 35 years old soooo

we have had some luck with OH them - the master from MID USA is actually a good one for china

it only comes chrome and the number is 45208 is the one we use its 100 bucks retail
 
Reply
Old Nov 28, 2014 | 02:12 PM
  #7  
Racepres's Avatar
Racepres
Seasoned HDF Member
Community Builder
Loved
Community Favorite
Top Answer: 1
Joined: Jul 2014
Posts: 8,610
Likes: 3,377
From: Cental, MI
Default

I would work for days on OE before I give Chiwan any $$ I don't have to!
A Shotgun bore brush and Cleaning swab holder..Chucked in a Handheld drill motor works wonders...Cups and O-rings are cheap at NAPA!
$0.02
 
Reply
Old Nov 28, 2014 | 02:38 PM
  #8  
johnjzjz's Avatar
johnjzjz
Seasoned HDF Member
15 Year Member
Top Answer: 3
Joined: Nov 2006
Posts: 12,878
Likes: 5,449
From: la la land jerzey
Default

Originally Posted by Racepres
I would work for days on OE before I give Chiwan any $$ I don't have to!
A Shotgun bore brush and Cleaning swab holder..Chucked in a Handheld drill motor works wonders...Cups and O-rings are cheap at NAPA!
$0.02
that is an owner that can be that way - i keep 3 of those kits in stock at all times and weeks go i do not have one for a job we sold them all - its a money thing even at 50 bucks and hour and we are more than that, plus the kit --- and when it come back in 3 weeks not working what then - you its oh well it dident work - me i have a guy who spent the same or more money fixing a junk master AND who pays for the new one china or not
 
Reply
HD Forum Stories

The Best of Harley-Davidson for Lifelong Riders

story-0

7 Times Harley-Davidson Chucked Tradition Out the Window

 Verdad Gallardo
story-1

7 Surprising Harley-Davidson Products that Are Not Motorcycles

 Verdad Gallardo
story-2

8 Best Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-3

10 Worst Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-4

Killer Custom's Jail Break Is The Breakout That Refused to Blend In

 Verdad Gallardo
story-5

Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

 Verdad Gallardo
story-6

Harley-Davidson Reveals Super Cool Cafe Racer Concept

 Verdad Gallardo
story-7

Engraved Rebellion: Inside Bundnerbike's Glam Rock II

 Verdad Gallardo
story-8

10 Motorcycles You Should Never Buy

 Joe Kucinski
story-9

10 Things Harley-Davidson Needs to Fix in 2026

 Verdad Gallardo
Old Nov 28, 2014 | 02:50 PM
  #9  
Racepres's Avatar
Racepres
Seasoned HDF Member
Community Builder
Loved
Community Favorite
Top Answer: 1
Joined: Jul 2014
Posts: 8,610
Likes: 3,377
From: Cental, MI
Default

Originally Posted by johnjzjz
that is an owner that can be that way - i keep 3 of those kits in stock at all times and weeks go i do not have one for a job we sold them all - its a money thing even at 50 bucks and hour and we are more than that, plus the kit --- and when it come back in 3 weeks not working what then - you its oh well it dident work - me i have a guy who spent the same or more money fixing a junk master AND who pays for the new one china or not
I'll give ya all that...Owned a Shop for years...don't now.
Most folk coming to a tech forum are attempting to DIY, not justify Shop Time.
For those who Have to have "New" at the cost of Quality... Well There is always Chiwanese ..."products". so yes there needs to be alternatives....
 
Reply
Old Nov 28, 2014 | 03:06 PM
  #10  
johnjzjz's Avatar
johnjzjz
Seasoned HDF Member
15 Year Member
Top Answer: 3
Joined: Nov 2006
Posts: 12,878
Likes: 5,449
From: la la land jerzey
Default

Originally Posted by Racepres
I'll give ya all that...Owned a Shop for years...don't now.
Most folk coming to a tech forum are attempting to DIY, not justify Shop Time.
For those who Have to have "New" at the cost of Quality... Well There is always Chiwanese ..."products". so yes there needs to be alternatives....
at the antique event swap meets a new old stock harley master fetches 300 bucks on a bad day raining all week end
 
Reply



All times are GMT -5. The time now is 06:25 PM.

story-0
7 Times Harley-Davidson Chucked Tradition Out the Window

Slideshow: Harley-Davidson built its reputation on nostalgia, but every so often, the company took a hard left turn into the future.

By Verdad Gallardo | 2026-05-20 11:18:19


VIEW MORE
story-1
7 Surprising Harley-Davidson Products that Are Not Motorcycles

Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.

By Verdad Gallardo | 2026-04-29 16:50:35


VIEW MORE
story-2
8 Best Harley-Davidson Motorcycles Ever

Slideshow: Not every Harley gets it right, but these are the ones that genuinely earned their reputation.

By Pouria Savadkouei | 2026-04-15 14:23:21


VIEW MORE
story-3
10 Worst Harley-Davidson Motorcycles Ever

Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.

By Pouria Savadkouei | 2026-04-01 20:01:09


VIEW MORE
story-4
Killer Custom's Jail Break Is The Breakout That Refused to Blend In

Slideshow: Killer Custom's "Jail Breaker" build focuses more on stance and visual aggression than mechanical overhaul.

By Verdad Gallardo | 2026-03-18 19:20:32


VIEW MORE
story-5
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.

By Verdad Gallardo | 2026-03-07 16:15:30


VIEW MORE
story-6
Harley-Davidson Reveals Super Cool Cafe Racer Concept

Slideshow: Harley-Davidson's new RMCR concept revives the café racer formula with modern hardware-and it may be exactly the reset the company needs.

By Verdad Gallardo | 2026-03-04 12:23:37


VIEW MORE
story-7
Engraved Rebellion: Inside Bundnerbike's Glam Rock II

Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.

By Verdad Gallardo | 2026-02-24 18:19:44


VIEW MORE
story-8
10 Motorcycles You Should Never Buy

Slideshow: There is no shortage of great motorcycles to buy, but we would avoid these ten.

By Joe Kucinski | 2026-02-19 14:50:51


VIEW MORE
story-9
10 Things Harley-Davidson Needs to Fix in 2026

Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.

By Verdad Gallardo | 2026-01-13 18:33:17


VIEW MORE