Master cylinder "gasket" to firewall with integrated bellows seal retainer.

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Dana67Dart

Dana67Dart

The parts you don't add don't cause you no trouble
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This is my latest reverse engineering project.

The CAD is ready to go, I just need to work out if my materials will stand up to brake fluid


Origional on the left. 3D printed on the right. Hard to see the details of the one on the right but they are all there!

PXL_20230209_005445327.jpg


PXL_20230209_005505917.jpg
 
Does anyone know what years used this part?

Or even a part number?
 
Now to narrow it down...

5-39-18 seems to be the foam gasket.

5-40-1 rubber bellows???

5-40-4 retainer????
Screenshot_20230208-202545.png




Looks like the metal one is
1828 389

Screenshot_20230208-204805.png


The boot is
1828 388

Screenshot_20230208-205053.png



Maybe 3461 205 is the plastictic one???? The number shows up in the 74 parts book too.
Screenshot_20230208-205309.png
 
I replaced to a 74 MC when I converted to Disc on my 68 Dart. The brakes wouldn't fully release. That was when I noticed the spacer under the packing material in the box which corrected the issue.
 
MidnightSwinger said:
Make some extras and I’d buy one! It was on my 74 when I removed the power brakes for manual
Click to expand...
I have to switch material in my printer and do some testing to make sure they won't desolve in brake fluid, but I'll let you know.

Was your mc a drum drum?

The parts book seems to indictate that there is a different number for the drum drum vs disk drum
 
Dana67Dart said:
I have to switch material in my printer and do some testing to make sure they won't desolve in brake fluid, but I'll let you know.

Was your mc a drum drum?

The parts book seems to indictate that there is a different number for the drum drum vs disk drum
Click to expand...
It is Disc/Drum. I wonder if I even need it now that I am thinking about it. I am converting to the lightweight master and it comes with its own spacer.

Still awesome, and I’ll be following along.
 
I have that same plate. Mine is Manual 10" drum converting to manual 11.75 discs. Not sure which year those pics are for but other than the nylon plate, the boot differs from my '72 and I don't have that medal adapter.
 
Looks good Dana, our 67 has foam, but it's been changed out over the years, so who knows what's what.
I think the aftermarket "foam" has been used in a variety of gaskets over the years for ease of production.
 
4spdragtop said:
Looks good Dana, our 67 has foam, but it's been changed out over the years, so who knows what's what.
I think the aftermarket "foam" has been used in a variety of gaskets over the years for ease of production.
Click to expand...
I actually have a foam gasket on my Demon too, between the Master and that plate. It didn't appear to have any other material between the nylon plate and the firewall?
 
So yours has foam as well as what Dana is making? I'll have to chk 67 parts manual to see what's what for ours. But brakes work great, factory disc with a drum/drum reservoir.
ajarofclay said:
I actually have a foam gasket on my Demon too, between the Master and that plate. It didn't appear to have any other material between the nylon plate and the firewall?
Click to expand...
 
4spdragtop said:
So yours has foam as well as what Dana is making? I'll have to chk 67 parts manual to see what's what for ours. But brakes work great, factory disc with a drum/drum reservoir.
Click to expand...
Let me know what you find, 4spd. I've got body, chassis and parts manuals on disc but from what I've searched I can't find Master cylinder details for the A body. It shows a complete view for the Imperial and another for B and E bodies but all they show for the A's then is the pedal assy. Very strange unless I'm missing something. I heard yay's and nay's regarding needing a different master with the disc brakes switch but decided to change over just to be safe. Glad I did so far considering what I found upon removing the original.
 
Yep, I'll post what I find out here. I've heard the same myth about the reservoirs. I actually have a proper #'d MC, but since brakes work fine, I'll leave it alone.
ajarofclay said:
Let me know what you find, 4spd. I've got body, chassis and parts manuals on disc but from what I've searched I can't find Master cylinder details for the A body. It shows a complete view for the Imperial and another for B and E bodies but all they show for the A's then is the pedal assy. Very strange unless I'm missing something. I heard yay's and nay's regarding needing a different master with the disc brakes switch but decided to change over just to be safe. Glad I did so far considering what I found upon removing the original.
Click to expand...
 
I would be tempted to put some form of sealer between the MC the plastic bellows holder and the plastic bellows holder and the firewall
 
Dana67Dart said:
I would be tempted to put some form of sealer between the MC the plastic bellows holder and the plastic bellows holder and the firewall
Click to expand...
There's a foam gasket that goes between the master and the nylon plate but nothing between the plate and the firewall. I'll probably put something there even if it's just making my own gasket.
 
Depending on thickness you could use sill gasket that framers use.
When you say "nylon plate" are you meaning the part Dana has made?
ajarofclay said:
There's a foam gasket that goes between the master and the nylon plate but nothing between the plate and the firewall. I'll probably put something there even if it's just making my own gasket.
Click to expand...
 
4spdragtop said:
Depending on thickness you could use sill gasket that framers use.
When you say "nylon plate" are you meaning the part Dana has made?
Click to expand...
Yes, mine appears to be nylon which became popular back then though I could be wrong. My new MC is here and I think I've found the boot on ebay.
 
The one I have that is used shows almost no crush so I'm not sure how well is would seal.

It does have a circle ridge around the hole for the pushrod so may d that would provide enough of a seal?
 
Yes, same here. It wasn't stuck to the firewall at all other than 50 years of probable Road film so I don't think it was ever silicone down or anything. I imagine I'm just going to put that on as is. I could probably use the old foam gasket that came off but I did find one available on eBay for $4 so I'll do that too.
 
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