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Changing Brake Fluid & Engine Oil

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Re: more blaspheme

Hi John, I took mine out clamped it up to a small Vacuum pump I have and there is no leak /ubbthreads/images/graemlins/nonod.gif.Consequently, you may have gotten hold of a buggered one.Additionally I do not know how well the RTV products bond to that rubber. I would suggest sealing it with super glue.--Just a thought---Keoke
 
Re: more blaspheme

[ QUOTE ]
[ QUOTE ]
No slit in my cap either.
D

[/ QUOTE ]

ahhh ... senior moment ... for Dave that is /ubbthreads/images/graemlins/grin.gif

memory check

[/ QUOTE ]
Hi John,
The senior moments are becoming increasingly frequent. The after effects of some surgery a while back. I'm becoming hesitant to post much of anything because of bad memory.

You are of course correct. I just pulled the cap to check & the JB Weld filler is still sealing the slit.

Thanks for correcting me,
D
 
Re: more blaspheme

Well Dave at least you have an excuse. I can get the urge to go to the John and when I get there I have forgotten what I came for.-Keoke- /ubbthreads/images/graemlins/yesnod.gif /ubbthreads/images/graemlins/lol.gif
 
Re: more blaspheme

Well I did not detect a slit in mine, but just where physically is this slit located.???---Keoke
 
Re: more blaspheme

Keoke,
The small grey spot in the center.
D
 

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Re: more blaspheme

OK Dave, thanks for the piccy,but there is not a slit in any one of the three I have installed.I will use a larger pump to check them tomorrow.---Keoke
 
Re: more blaspheme

[ QUOTE ]
I'm becoming hesitant to post much of anything because of bad memory.


[/ QUOTE ]

Hi Dave,

Don't do that!! Use it or lose it (or something like that .. I can't remember /ubbthreads/images/graemlins/wink.gif

I think we need Greg W. to weight in here. I find it hard to believe that we both got defective seals. But stranger things have happened.

Cheers,
John
 
Re: more blaspheme

[ QUOTE ]
Keoke,
The small grey spot in the center.
D

[/ QUOTE ]

OH! You guys mean that slit!! /ubbthreads/images/graemlins/laugh.gif I hooked it up to the larger Vac Pump put it in the purge mode and YES there is a dam slit there,or at least there was. Thanks for the heads up I did not see it at the git go.---Keoke- /ubbthreads/images/graemlins/thumbsup.gif
 
Re: more blaspheme

Well, looks like I have a case of the slits too. So I think it was intentional. I would guess it’s for slow equalization of pressure? I’ll see if I can find an email address for HELP and ask them what’s up.
 
Re: more blaspheme

gents,im not gettin this,ya buy a seal for resv.cap but its got a "slit" in it,is that the deal? then you buy rtv to seal the "slit".if thats whats bein done its a heck of a trick,why dat "slit" be dar in da first place? perhaps its "not ment to totaly lock the system up? why do there be a hole in the top of the cap? any one blow a brake cyl. yet? got leaks? maybe braking that dont release to quick when ya take your foot off the pedal,brakes that "bite" to fast?well then thats a nifty accumulator ya just built,why they tell ya to keep your hole clean,the one on top of cap that is? trying to keep moisture out of a system that wont be effected by it for about 100 years seems futile to me, the prospect of doin this trick has me more "confuseded" then i normally am,and thats really bad! /ubbthreads/images/graemlins/confused.gif
 
Re: more blaspheme

Hi Anthony,

One of the main reasons I'm trying the seal in the top cap is to protect the paint (and my paint is brand new and cost big $$$ so I might be bit more concerned than the average bear). I've heard .. and I've seen evidence .. that there is some atomization (or fine spray) of the brake fluid that escapes the top cap vent hole when you tool down the road. Think about the vibrations from the engine, the heat, the brake fluid slopping around as you dive from corner to corner or even just cruise at 70 all day long. That small amount of brake fluid mist ends up in the engine compartment and unless you are running Dot5 will eventually affect the paint. Take a look at older cars unrestored cars and you will see a good deal of paint damage around the brake fluid reservoir and right behind it as the air pushes it back. The paint on the reservoirs doesn't look to be in a very good state either. So I'm just trying to reduce the mist that can escape. Leaving the tiny slit would probably be o.k. as it will still seal the mist but allow the fluid chamber to equalize.
Cheers,
John
 
Re: more blaspheme

Yes Anthony, I have been musing about the perpetual warning for keeping the vent open in the caps by the major suppliers.This tiny slit which my small Vac machine would not detect just may be there to equalize sudden pressure changes I will check it out.--Fwiw---Keoke /ubbthreads/images/graemlins/hammer.gif
 
Re: more blaspheme

in original cap or Moss replacement that **** hole in center is part of a dual layer of metal (outer-inner) that makes up cap, in trying to adapt to Ezeebleed (tire pressure) system I tried to mash flat with hammer, then drill and connect to tube but real struggle to get tight seal, very complex cap structure, down around 10lbs air pressure leak minimal and worked ok.
 
Re: more blaspheme

Fellow Lagunatic: sounds as if adapting SU overflow tube to fit hole in cap would solve problem and keep things verrrry British old chap and add more flavor and color to the drip pan on garage floor
 
Re: more blaspheme

[ QUOTE ]
gents,im not gettin this,ya buy a seal for resv.cap but its got a "slit" in it,is that the deal? then you buy rtv to seal the "slit".if thats whats bein done its a heck of a trick,why dat "slit" be dar in da first place? perhaps its "not ment to totaly lock the system up? why do there be a hole in the top of the cap? any one blow a brake cyl. yet? got leaks? maybe braking that dont release to quick when ya take your foot off the pedal,brakes that "bite" to fast?well then thats a nifty accumulator ya just built,why they tell ya to keep your hole clean,the one on top of cap that is? trying to keep moisture out of a system that wont be effected by it for about 100 years seems futile to me, the prospect of doin this trick has me more "confuseded" then i normally am,and thats really bad! /ubbthreads/images/graemlins/confused.gif

[/ QUOTE ]
More modern master cylinders have a bellows type seal on the lid. Since the rubber is folded & very flexible it does not act as a pressure accumulator but only displaces slightly to provide for the slightly varying fluid volume. The hole in the metal lid allows for volume changes on the fluid side without exerting pressure on the fluid. A slit in the rubber is not needed to equalize pressures. The seal prevents exchange of moisture laden air through the cap hole & keeps the fluid drier.

Why the seal in question has a slit is unknown. Sealing the slit has proven to not have any adverse effects & does provide a fully sealed system. I don't think that rtv is compatible with brake fluid. I do know that JB weld works well.

Some master cylinders have residual pressure valves which maintain around 2 psi on disc brakes, to 10 psi on drum brakes, of positive pressure on the braking system even when the pedal is fully released. This residual pressure prevents unwanted entry of air into the wheel cylinders when the brakes are not applied. It keeps the cups slightly expanded. The retraction forces on the brake shoes & calipers are great enough to overcome this residual pressure so that the brakes don't drag. This residual pressure is higher than any pressures that would be exerted by the master cylinder rubber cap seal.
D
 
Re: more blaspheme

[ QUOTE ]
I do know that JB weld works well.
D

[/ QUOTE ]

Hi Dave .. you're probably right about the RTV .. I'll do a little experiment to see if they are compatible.

My only concern with JB weld was sticking to the flexible rubber ... From their website:

Q: Is there anything that J-B Weld WON'T bond to?

A: J-B Weld will not adhere to, or bond well to:

* Any flexible rubber surface
* Leather
* Vinyl
* Canvass
* Polypropylene plastic
* Polyethylene plastic

but it sounds like it sticks well enough.

Cheers,
John
 
Re: more blaspheme

[ QUOTE ]
in trying to adapt to Ezeebleed (tire pressure) system I tried to mash flat with hammer, then drill and connect to tube ...

[/ QUOTE ]

Jay,

One of the caps included with the system worked fine on the Healey reservoir. The rubber gasket needed a little trimming to clear one of the inside fittings. I do find I need to carefully tighten the cap .. not too tight or the gasket will twist ... and then check with the pressure to see if it holds. Only then do I fill the eezibleed with fluid for the pressure bleeding. I also found the lower pressures 10-15 worked fine.

Cheers,
John

p.s. check your private messages (click on the red blinking icon next to your name above)
 
Re: more blaspheme

o.k,i can respect an individual thats "attemting" to save his engine compartment paint job,and yes it is true that a pure accumulator is introduced to pressure greater than ambiant as in 3000 psi aviatin types,but sealing the break fluid canister is a close enough facsimile for me to call it one.if i were to try and tell you that you could never seal moisture out of you system at all,and the protective benifit of brake fluids when moisture is introduced,youd all come over and have me fitted for a nice white jacket with arms that tie behind the back "renfru" style, so READ THIS! www.stoptech.com/tech_info/wp_brakefluid_1a.shtml and keoke ill tell up front im a 40 regular. /ubbthreads/images/graemlins/rolleyes.gif
 
Re: more blaspheme

Hi Anthony,
I like the Stoptech guys. Even talked to one of them on the phone. I’ll disagree with you on the point about the benefit of moisture in the brake fluid. It’s not good to have water in the system, it’s the ability of the fluid to absorb water. A quote from your source:
“Hence the need for brake fluid to absorb this unwanted house guest. Because brake fluid absorbs water into solution, the local concentration levels are typically low enough that corrosion is slowed dramatically. As an added benefit, when exposed to low temperatures, the solution state prevents the water from pooling and freezing on its own. While water in brake fluid will certainly increase the solution viscosity at low temperatures, this is much more desirable than having little chunks of ice plugging up the system!”
 
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