Ye Olde Master Cylinder Changeout Threade! (advice needed)

[bstuke]

Yes that is why the gouge is there.

Make sure you adjust out all the pedal pressure on the MC. Even if you have a slight amount of pressure on the MC coming from the pedal when in it's resting position you will have problems..

[NiceGuyEddie]

so i guess it was angled "downwards" and the top was rubbing against something?

i can't recall how it was installed, i'm assuming like in the photo, with the loop on the bottom.

.

[bstuke]

Originally Posted by NiceGuyEddie

so i guess it was angled "downwards" and the top was rubbing against something?

i can't recall how it was installed, i'm assuming like in the photo, with the loop on the bottom.

.

Most likely. Make sure you get up in there with a bright light and make sure it all lines up good.

[NiceGuyEddie]

I don't have any old build photos, but I took a few before I took it out. you can see the part that is ground down… I don't recall why we had to do this, but it looks like I did have it mounted with the loop down. I vaguely remember this was the only way it would fit.

i even have the black plastic bumpy thingy on the pedal.

modified donor pedal, donor pedalbox, donor master, I wonder why everyone doesn’t have this problem. I guess I really am a schlimazel !

.

[JKleiner]

Originally Posted by NiceGuyEddie

i even have the black plastic bumpy thingy on the pedal.

Eddie, you're going over my head with the technical terms. Can ya' dummy it up a little for me

Jeff

[cobradawg]

That new adjustable plunger will help alot, now you can adjust it so both brake and clutch petals are the same height. By the way I would love to meet you some time to shake your hand , you have a great sense of humor, and the patients and persistance of Jobe. You da man!

[NiceGuyEddie]

thanks dudes, can someone please whet my appetite and 'splain me how to keep the pedal from "bouncing up"? that's what the little bungey was for, I can't see what otherwise keeps the pedal from doing that. it's not like the head of the push-rod "locks" into the master.

i am not using that brake light/spring mechanism from the Mustang box for the brake light. i remember it somehow attached to the brake pedal stud, and then to the cage. (and i gave it to Mikey Likes It!)

[Big Blocker]

Eddie,

The Black plastic "bumpy" thing is there to provide a surface for a plunger type brake light switch to press against when you are NOT using the one you show in the baggie. The flat surface on the master cylinder push rod is there to do the same thing for the brake light switch if you do use the one you show in the baggie.

The master should have enough return spring pressure to hold your brake pedal up close enough to the frame so it won't "rattle". Once you get everything assembled and adjusted, you should have a good working system with good pedal travel. If your pedals don't line up, you may have to "reconfigure" them to do so. If your clutch pedal was never cut or modified, I'd assume that it's bone stock and the brake pedal should line up with it. The modification to the brake pedal doesn't change it's angle from it's pivot point.

Doc

[NiceGuyEddie]

thanks dude, my clutch pedal was bent with the pedal bender, but not so great. i hope i can straighten it out a little better and get the pedals more even.

still not understanding how the pedal won't lift "up", the pushrod just goes right inside the master hole with nothing holding it in place except gravity acting on the pedal (i think?) i guess i'll have to wait until i assemble everything.

.

[cobradawg]

Eddie; If you have the brake petal resting against the full out stop and adjust the new plunger till it bottoms out against master cylinder piston it cannot come out.

[NiceGuyEddie]

(I forgot to look at the inside of the old master cylinder to see if it was scored.)

top photo is the bump stop thingy. it wasn't doing anything before. I now understand that to keep the pedal from "bouncing", the pushrod is to be adjusted so the pedal presses against the crossbar in the frame. that makes the pedal a little higher than it was previously, and that's okay, but I'll need to somehow secure a rubber bumpstop on the crossbar. I hope my right angle drill will fit in there.

and now, the more harcore questions.

seems the master won't be as plug-and-chug as I hoped. the larger hole is in the front of the old master, and it's the opposite on the new one. our friend Mark from Breeze sent me two adapters. they screw into the new master cylinder, and also screw into the old one, but the female sides won't accept the male fittings on the car.

the male fittings on the car seem to fit into the new master (trying them separate) but with my rear brake retro, I've learned these threads can look very similar and may seem correct, but may not actually be, so I don't want to force anything.

Edit:

http://www.imperialsupplies.com

you can buy all sorts of adapters here. the real question is what are the fitting sizes on the old and new master?

.

[NiceGuyEddie]

http://www.oreillyauto.com/site/c/de...2033&ppt=C0248

http://www.oreillyauto.com/site/c/de...2033&ppt=C0248

Breeze 21565 = Adaptor, 3/8-24 Female IF to M10-1.0 Male bubble flare
Breeze 21566 = Adaptor, 3/8-24 Female IF to M12-1.0 Male bubble flare

Both of these screw quite nicely into each master cylinder, but in opposite ports. They fit better into the new cylinder, a wee less nice on the old one, but it's worn, and it by no means does it seem as if i am forcing them in.

Confirming, JeffK said I have on Mustang Cylinder:
Primary Outlet Size= (2) M10x1
Secondary Outlet Size = M12x1


So don't i need:

M12-1.0 Female ??? flare to M10-1.0 Male bubble flare
M10-1.0 Female ??? flare to M12-1.0 Male bubble flare

oreilley's #267000 seems to be close for the first one, but i don't know what kind of flare is already on there.

i'll call Mark tomorrow, unless, of course, someone can figure this out.

and for the record, if i make new brake lines with fresh fittings, i won't know the fitting on the other side. down the line.. down the line, etc.

going on vacation soon and i'd love to order these before i leave.

.

.

[CraigS]

Re: brake pedal position. I don't like the idea of adjusting the pushrod so the pedal is against the cross tube on the frame. The idea of an adjustable pushrod is so you can place the pedal where you want it. My car came came w/ a small bracket for the plunger style brake light switch so I can adjust the switch which limits the up/rearward pedal travel.

Click to enlarge
The switch has a plastic body and came w/ just one nut.So the nut is on the other side of the piece of aluminum and is easy to adjust by hand. The small hose clamp is tightened on this side of the aluminum so the switch is captured. If you don't have this style switch you cold subsitute a 1/4 inch carriage bolt w/ two nuts.Coat the fat head of the bolt w/ some silicone and let it dry before you install it to cut down on rattles or use the plastic rubber bumpy thing if it lines up.
http://shop.advanceautoparts.com/buy...t-400-212.html

[NiceGuyEddie]

Thanks for that idea, Craig. i think i will wind up with something between what you did, somehow using the spring/brake light switch anyway, or just adjusting the pedal so it's 1/16" away from a rubber bumper (rather than flush against it.)

here are my brake flares if someone can help me with my fittings. is this a standard flare, inverted flare, double-flare, or ???

[Big Blocker]

"adjusting the pedal so it's 1/16" away from a rubber bumper (rather than flush against it.)"

Good idea . . . you want about 1/8" to 1/4" free space between the frame (or a frame mounted bumper) and the pedal arm. Last thing you want is the pedal to be applying pressure to the master when you're NOT on the brakes . . . causes disks to "drag".

Get the master mounted and then put the push rod into it and see where it's pedal mounting hole lines up with the stud on the pedal arm, with the pedal pulled all the way up to contact the frame (or bumper). Then adjust the push rod to give you a small amount of free-play and you'll be good-to-go.

Remember, Eddie, the master has enough spring pressure internally to lift the pedal by itself, you shouldn't need any "additional" springs. If the above adjustment makes your pedal sit too high, you can cut a wedge (3/4 of the way thru) out of the back of the arm, bend the arm down to close the wedge and then have it re-welded.
OR
build a bump stop that makes the pedal top out (return) lower and then adjust the push rod accordingly.

As for your flares, they look to be standard flares . . . but we would need a picture of the other side to determine for sure (looking into the tube) If looking in to the tube you see little funnel-like \ / ends, they are standard . . . bubble flares look more like a compression ring ( ) is installed on the line. Sorry for the crude symbols.

HTH

Doc

[NiceGuyEddie]

at this point, I would be happy to remove my front brake lines, get new single fittings and make new flares.

the Master is Raybestos MC390217. the paperwork that came with it said nothing about the flare type, but we know it uses:

M10-1.0 Male bubble flare
M12-1.0 Male bubble flare

I have both OEM/SAE and OEM/Metric flaring tool kits, like Autozone 27015 & 27012.

so my final question on this subject is "is a double flare a bubble flare?" some things online say "double/bubble flaring tool" but you never know.

.

[CraigS]

To me a double flare is a two step process where you flare the line and then fold half of that flare back into the funnel shape. A bubble flare --oh heel, this is much better than I can describe it.
bubble flare vs double flare - Google Search

[JKleiner]

Eddie,
There is a lot going on here but I think I have it figured out. You're going to need to take a step or two back.

Let's begin with the double flare and bubble flare question:



The one on the left is a double flare---note that it is concave
The one on the right is a bubble flare---note that it is convex
Take a good look at the flare nuts and the difference between them because that is going to be important in a minute.

The ports on your old Mustang MC and the new Cobra MC are both set up to accept a bubble flare. See how the seat is concave, tapered down into the hole that fluid passes through? Now look into the ports of the black MC pictured in post #71 which is made to accept a double flare and you'll see that the seat is convex, tapered away from the hole.

We want to match concave to convex and vice versa; i.e. concave seat to convex line

Looks to me like when you made your original brake lines you used the old bubble flare nuts but put a double flare on the lines. Look closely at the nuts in post #74 and you'll see it. What you did was put concave double flares into concave bubble flare ports. Frankly I am surprised that you got them to seal.

Long story short, you have two options, both of which will require reconfiguring or replacing the lines to the master cylinder:

1) Keep the bubble nuts on the lines and remake the flares into bubbles.
---OR---
2) Cut the flares off of the lines, replace the nuts with the proper double flare style and put a double flare on the lines then use them with the double to bubble adaptors. On the subject of those adaptors it looks like you have a 3/16 to M12 (265000) which would be correct but the other is 3/16 to 3/16 (271300)---it needs to be 3/16 to M10.

Good luck!

Jeff

[pavieSD]

Here's a better picture that illustrates the difference between double and bubble flare.

[NiceGuyEddie]

great stuff, guys. definitely understanding the difference between the two types of flares as well as the shape of the end of the fitting itself. I should have just done a google image search DUH!

Jeff's information is spot-on.

i fully understand jeff's two choices, including that instead of 3/16-3/16 i need one of them to be 3/16 to M10. that's probably what threw me off the most.

• this won't shock anyone, but the flares were made by the same guy that built my first engine.
• i had loads of practice doing double flares when i did my rear brakes.
• one of my fittings is a bit stripped, so i'll be happy to buy new ones and make new flares.

….so I got it!

my choices are:

use two fittings: fitting & double flare + adapter fitting
one fitting: fitting & bubble flare (need to buy bubble flare tool).

bubble flare tools seem to be significantly more expensive than double flare tools, so I will probably go the adapter route. unless I can find a SoCal local that has a quality bubble flair tool.

[pavieSD]

If you're not in a hurry, amazon has a nice package deal:

Amazon.com: Lisle 31310 Double Flaring Tool Set: Automotive

Amazon.com: Lisle 31310 Double Flaring Tool Set: Automotive

Lisle 31310 Double Flaring Tool Set by Lisle $31.04
In Stock.
Ships from and sold by Amazon.com.
This item ships for FREE with Super Saver Shipping. Details

Ridgid 32975 1/8-Inch to 5/8-Inch Close Quarters Tubing Cutter by Ridgid $12.70
In Stock.
Ships from and sold by Amazon.com.
Eligible for FREE Super Saver Shipping on orders over $25. Details

OEM 25179 Tubing Bender by OEM $12.00
In Stock.
Ships from and sold by Amazon.com.
Eligible for FREE Super Saver Shipping on orders over $25. Details

[canuck1]

Eddie,

I used a couple brass adapters, but would go a different route if I were to do it again.

My front lines are pretty short, yours may be as well, If it were me... I would just buy a couple lengths of pre flared (bubble flare) line, cut one end off, use a standard tube nut and double flare the end to fit the corresponding connection at that end of your line (assuming that's what you need?).

Sean

[NiceGuyEddie]

GUYS

fitting vs. adapter - i hope i got this right.

I decided I will do the two fitting method, cutting off the flares I have, putting on fresh fittings, and making new Inverted Flares.

I know I need a 3/8-24 Female IF fitting, but I am having trouble finding the correct fittings. Breeze does not have them, just the adapters.

I even went to Autozone and O'Reilleys, and they could not find the "standard" fittings used on a 1994 Mustang Cobra. Everything on their website shows adapters, I just need the standard fittings.

On Summit, it lists fitting end 1, fitting end 2, fitting 3, male thread, female thread, etc. even then, everything seems to be adapters.

all I need is two (2) 3/8-24 Female IF (Inverted Flare) Fittings - if I am correct.
EDIT:
all I need is two (2) 3/8-24 Male IF (Inverted Flare) Fittings - if I am correct.


I would appreciate it if someone can find them for me, somewhere, anywhere, then I will see if I can get them from Autozone or somewhere else.

cheers,

[NiceGuyEddie]

test... where is page 3?

keeps going in a loop.

EDIT: i can see page 3 with Internet Explorer

.

[2FAST4U]

Works for me

[QSL]

Confused... do you need a fitting to go on the end of your tube? That would be a male, not a female? If you simply need the nuts to put on your tubing, i am sure i have some, or get a generic piece of tubing with them on it at the parts store and cut the tubing in half and you have two nuts!

[NiceGuyEddie]

doing this "BLIND" - for some reason, I can't see page 3 on my computer, (loops to 3) but I can see it on my smartphone. (if I hit "post reply" it replies.)

EDIT: i can see page 3 with Internet Explorer

this page from Edelmann is close, but i can't get just the right one. Standard Steel Nut comes close, they have 3/16" line, but i can't find the right thread size.

http://www.plews-edelmann.com/invert...tube-fittings/

Cheers,

[NiceGuyEddie]

Originally Posted by QSL

Confused... do you need a fitting to go on the end of your tube? That would be a male, not a female? If you simply need the nuts to put on your tubing, i am sure i have some, or get a generic piece of tubing with them on it at the parts store and cut the tubing in half and you have two nuts!

this guy is a BLITHERING GENIUS!

DUH how can i be so stupid??????? (retorical, don't answer.) haha

i is an engineer, and i is tend to over-think at times.

i'll visit Pep Boys tonight and see what i can do!



Sean: i may do exactly what you suggest, but first, i want to see if i can save my existing brake lines. it's short on one end, so i am guessing 50/50 if i have enough room for the flaring tool once the end is cut off.

Cheers,

[cobrathegreat]

Eddie, try a Napa near you. Your chances of finding what you need are much higher there than at Pep Boys.
They have lines with the fittings and just fittings etc.
BTW man, you are making this harder than it is supposed to be!!!
Good luck and keep us posted.

[NiceGuyEddie]

i went to find a pre-made brake line like QSL suggested, and wouldn't you know it, they had loads of fittings below the rack. must have been 100 of them, it took me a while to find it. $2.49 for a pack of five, just 1/4 mile from my house.

i hadn't the slightest clue these would be stock items, i thought they would be special order like the -AN fittings for my rear brakes.

of course next time, it will be obvious!

.