The Ford Barn

rbone · 08-18-2020, 06:08 PM

I'm trying to make an adapter for my master cylinder (M1050) so that I can use my pressure brake bleeder on it. I am having a heck of a time finding the thread type on the fill plug. I also see that some of the new master cylinders on the internet have what appears to be a removable plug inside the fill cap. Does anyone know the thread type for the fill plug? The information I had was 1 1/4 MNPT, but that is not correct. It is smaller than that and has much finer threads.

Two questions - 1. what is the correct thread type for the regular fill plug? and 2. does anyone have one with the removable plug in the filler? If so, is it a regular 1/4" NPT pipe fitting?

Here is a link to the cylinder on which you can see the fill plug and cap.
https://www.partsgeek.com/gbproducts...CABEgLyZfD_BwE

Thanks,
Ron

fordor41 · 08-18-2020, 10:48 PM

if it like everything else, the co. can put just about any thread they want. could take the cap to a machine shop and have them check the thread and fab one for you.

Mart · 08-19-2020, 04:36 AM

I've pressure bled the ford cylinders by making a flat plate that I clamp over the opening. The plate has an 1/8 npt thread in it and a common barbed fitting in it. I use a piece of inner tube rubber between the plate and the reservoir. I have also used a plate on dual master cylinders with the large opening.

I can warn, though.. "Prepare for spillage".

Mart.

big job · 08-19-2020, 05:05 AM

Marts way is the simple fast way. I remember those sold in auto part stores It had a
chain that went around the cylinder with a rubber gasket.

Don · 08-19-2020, 06:37 PM

I took cap from old MC or even new one and drilled a tap for 1/4 pipe,then used a compression fitting to apply air and fluid,,when done ,just removed the comp fitting and put a 1/4 pipe plug in BE SURE TO DRILL A SMALL VENT HOLE IN PIPE PLUG!!
I think I used another gasket on cap and really tightened it so no leaked,, couldn’t get it loose ,that why I left it there and used pipe plug,
Like Mart said be prepared forleakes,,,after you get itplumed up ,just put about 15# air to see if it holds pressure before putting fluid in container,,
I made my own bottle with a gauge and valve and reg,,worked great,best brakes I ever had on 35

russcc · 08-19-2020, 06:52 PM

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Another off topic option is to vacuum bleed the brakes. You can get the vacuum hand pump on loan form Auto Zone in my area. But you have to buy the reservoir, $10. including shipping from Discount Tool. These are all Mityvac products. As you bleed each wheel you can see the air bubbles in the fluid which ends up in the reservoir which you can then re-use. No mess, spilled fluid, the only out off pocket expense is $10., and then you can use the vac pump for vacuum, fuel, EGR and other system testing.

08-18-2020, 06:08 PM	#1
rbone Member Join Date: Mar 2016 Location: Frisco, TX Posts: 95	Master cylinder fill cap I'm trying to make an adapter for my master cylinder (M1050) so that I can use my pressure brake bleeder on it. I am having a heck of a time finding the thread type on the fill plug. I also see that some of the new master cylinders on the internet have what appears to be a removable plug inside the fill cap. Does anyone know the thread type for the fill plug? The information I had was 1 1/4 MNPT, but that is not correct. It is smaller than that and has much finer threads. Two questions - 1. what is the correct thread type for the regular fill plug? and 2. does anyone have one with the removable plug in the filler? If so, is it a regular 1/4" NPT pipe fitting? Here is a link to the cylinder on which you can see the fill plug and cap. https://www.partsgeek.com/gbproducts...CABEgLyZfD_BwE Thanks, Ron Last edited by rbone; 08-18-2020 at 06:13 PM.

08-18-2020, 10:48 PM	#2
fordor41 Senior Member Join Date: Oct 2011 Location: elmira,ny Posts: 1,516	Re: Master cylinder fill cap if it like everything else, the co. can put just about any thread they want. could take the cap to a machine shop and have them check the thread and fab one for you.

08-19-2020, 04:36 AM	#3
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 8,745	Re: Master cylinder fill cap I've pressure bled the ford cylinders by making a flat plate that I clamp over the opening. The plate has an 1/8 npt thread in it and a common barbed fitting in it. I use a piece of inner tube rubber between the plate and the reservoir. I have also used a plate on dual master cylinders with the large opening. I can warn, though.. "Prepare for spillage". Mart.

08-19-2020, 05:05 AM	#4
big job Senior Member Join Date: Sep 2013 Location: Dighton, Mass Posts: 1,230	Re: Master cylinder fill cap Marts way is the simple fast way. I remember those sold in auto part stores It had a chain that went around the cylinder with a rubber gasket.

08-19-2020, 06:37 PM	#5
Don Senior Member Join Date: May 2010 Location: Ashland KY Posts: 1,159	Re: Master cylinder fill cap I took cap from old MC or even new one and drilled a tap for 1/4 pipe,then used a compression fitting to apply air and fluid,,when done ,just removed the comp fitting and put a 1/4 pipe plug in BE SURE TO DRILL A SMALL VENT HOLE IN PIPE PLUG!! I think I used another gasket on cap and really tightened it so no leaked,, couldn’t get it loose ,that why I left it there and used pipe plug, Like Mart said be prepared forleakes,,,after you get itplumed up ,just put about 15# air to see if it holds pressure before putting fluid in container,, I made my own bottle with a gauge and valve and reg,,worked great,best brakes I ever had on 35 __________________ DON P

08-19-2020, 06:52 PM	#6
russcc Senior Member Join Date: May 2010 Posts: 2,871	Re: Master cylinder fill cap Sponsored Links (Register now to hide all advertisements) Another off topic option is to vacuum bleed the brakes. You can get the vacuum hand pump on loan form Auto Zone in my area. But you have to buy the reservoir, $10. including shipping from Discount Tool. These are all Mityvac products. As you bleed each wheel you can see the air bubbles in the fluid which ends up in the reservoir which you can then re-use. No mess, spilled fluid, the only out off pocket expense is $10., and then you can use the vac pump for vacuum, fuel, EGR and other system testing.