Topic: Rebuilding a single resevoir Master Cylinder 1965 Mustang

[must69]

I am trying to rebuild the master cylinder.  The piston does not want to come out.  I am soaking it in some penetrating fluid.  Any suggestions?
Thanks.
Phil

[67350#1242]

After soaking, I'd try compressed air to force it out.    If that not good enough, rigging up a grease gun should do the trick.

A couple months ago, was rebuilding a K/H 4 piston caliper and had to use grease gun to force out the pistons that were rusted in the bores.  Was a PITA but they came out with no damage.  Some trouble cleaning out grease afterwards, but worth the effort.   (you can put much more force with a grease gun than with compressed air)

[Scott302]

100 psi into the brake line port and a catchers mitt on the back side.
 
Regards,
Scott

[rockhouse66]

Be very careful with the compressed air.  The piston will come out of there like a rocket!

[must69]

All: Thanks!  I never thought of using a grease gun to get it out.  The compressed air did not do it.  I used a screw extractor in the piston and turned it with a wrench.  Came out very easily.   Does anyone know if there is a direct replacement top available that is copper?  I have what I believe to be the original and it is stamped Ford and is made of copper. 

Thanks.
Phil

[Bob Gaines]

All: Thanks!  I never thought of using a grease gun to get it out.  The compressed air did not do it.  I used a screw extractor in the piston and turned it with a wrench.  Came out very easily.   Does anyone know if there is a direct replacement top available that is copper?  I have what I believe to be the original and it is stamped Ford and is made of copper. 

Thanks.
Phil

Phil, if you are referring to the master lid (top) then it is not copper but steel that has a zinc Dichromate (gold) coating. FYI from the factory the outside master and lid was painted black by the sub contractor before being delivered to the assembly plant. The cheap paint didn't last long and flaked or rusted off which is why many are not aware of the original black.

[ChrisV289]

I'd be curious to know the steps to rebuild it.  Did you get the rebuild kit from NPD?

http://www.concoursmustang.com/forum/index.php?topic=14432.msg89883#msg89883

[must69]

Yes, I obtained the kit from NPD.  I have honed the cylinder and ready to reassemble.  Looks like a simple process. 

[must69]

Chris, just looked at your post.  Agree, would be nice to have some instructions included. I have attached a pdf of the way the parts came out and how I think they go back in.  <a href="" target="_blank"></a>

[must69]

Bob, I have attached a pdf of the master cylinder cap.  I believe it is the original. The top photo is before blasting (black as you stated), the bottom after blasting.  Looks more like copper than zinc dichromate.  The replacement is from Scott Drake, but is somewhat taller.  Which is correct for a 1964-1/2 Dearborn with 4 wheel manual drum brakes, 260, auto?  I ask because I see you are a judge.
Thanks.
Phil

[carlite65]

the domed cap would be correct for your application. it too would be painted black with the master cyl. paint as an assembly.

[Bob Gaines]

Bob, I have attached a pdf of the master cylinder cap.  I believe it is the original. The top photo is before blasting (black as you stated), the bottom after blasting.  Looks more like copper than zinc dichromate.  The replacement is from Scott Drake, but is somewhat taller.  Which is correct for a 1964-1/2 Dearborn with 4 wheel manual drum brakes, 260, auto?  I ask because I see you are a judge.
Thanks.
Phil

Phil, in my tunnel vision I assumed you were talking about a disc brake single reservoir master cylinder . I can say with a high confidence level the observations to be the case on a disc brake version. On the other hand I am not sure on the manual brake version. I can say that if you blasted the inside portion of the cap and it is still a gold/copper color then it is not zinc dichromate. The least little abrasion let alone a purpose blasting would take away that dipped gold coating.  I am a judge for 65-70 Shelby cars which all had disc brakes.