Rebuilding Paramount Master Cylinder

[Grandmas Flying Couch]

My mechanic and I have taken out the master cylinders when we went to change the 4 O-rings listed in the parts diagram.  All the rings match up perfectly except the one on the valve.  The parts diagram calls for AN6227-3 (MS28775-008) but the one on the brass valve appears to be a flat washer unless it formed this way over time from the hydraulic pressure.  In the parts diagram the O-ring for the valve appears as number 87.  O-rings 85 and 91 match up perfectly.  In one of the pics I threw the supposed O-ring on the valve for a visual.  The rubber on the valve is still soft, I'm tempted to change the other O-rings as they have taken on a square cross section and just leave the rubber washers, what do you all think?  Kits provided to rebuild these master cylinders include the same O-rings I have.  

[jetdriven]

i think that is Called a statoseal and. Is not avaialble anymore   

[carusoam]

Remembering the statoseal issue, but none of the detail... I looked it up...

It seems to be a product by Parker... Might give enough detail to determine next steps...

http://www.allsealsinc.com/statoseals.pdf

Or call Dan at Lasar to see what the Mooney world is using lately for that...

Best regards,

-a-

[Heloman]

There's a different style that holds an O-ring. Not sure if you could replace just that piece, I might have one.

Edited October 18, 2019 by Heloman

[Grandmas Flying Couch]

3 hours ago, Heloman said:

There's a different style that holds an O-ring. Not sure if you could replace just that piece, I might have one.

I don't know, I would have to put the part in and see if it operated as a check valve like this one does.  I am going to assemble them tonight using existing washers, they are nice and pliable with no cracking.  Even if one were to die 5 years from now I have the other brake and don't use brakes much anyway.  It would probably be a progressive failure in the mean time I will look for the parts.  I don't think it is a statoseal like seen on the fuel valve as those are incorporated into a washer, perhaps there are variations.  

[Heloman]

4 hours ago, Grandmas Flying Couch said:

I don't know, I would have to put the part in and see if it operated as a check valve like this one does.  I am going to assemble them tonight using existing washers, they are nice and pliable with no cracking.  Even if one were to die 5 years from now I have the other brake and don't use brakes much anyway.  It would probably be a progressive failure in the mean time I will look for the parts.  I don't think it is a statoseal like seen on the fuel valve as those are incorporated into a washer, perhaps there are variations.  

???? I'm only saying that O-ring doesn't go there, there is another type that does hold an O-ring, the brass piece looks different than yours. I'm not saying they're interchangeable, maybe they are, but probably not; good luck.

[Grandmas Flying Couch]

That's how I understood you, I was saying the only way I would know would be to pop in the alternative brass piece and see if it worked.  I was replying to jet driven about the statoseal.  I was tired and unclear when I posted.  I am going to keep the current brass valve as is.  Looks like it was available with the seal as a service item but no longer.  

[Grandmas Flying Couch]

Update: Rebuilt both cylinders using new O-rings and keeping the brass valve with original seal that was still pliable.  Both breaks work great.  Remember that the cotterpin that contacts the fluid inside the cylinder is stainless MS24665-151.  Also a piece of safety wire tied in a loop from inlet of the cylinder to rod to keep the cylinder collapsed while installing the snap ring will help you with your sanity.  

[JoeM]

Rebuilding my paramount master cylinder, the statoseal valve and seal are damaged. Any ideas on where to get a replacement? I would be willing to buy a used master cylinder if that part was usable.

[Yetti]

21 minutes ago, JoeM said:

Rebuilding my paramount master cylinder, the statoseal valve and seal are damaged. Any ideas on where to get a replacement? I would be willing to buy a used master cylinder if that part was usable.

Call LASAR  and then ask for the fancy seal kit for the gas colater while you are getting things.

[JoeM]

Good advice. Had already done that. Dan said it has been 12 years since he could get this. He recommended a used master cylinder. Of course Mooney offers their upgrade kit for $2,500.

[Yetti]

1 hour ago, JoeM said:

Good advice. Had already done that. Dan said it has been 12 years since he could get this. He recommended a used master cylinder. Of course Mooney offers their upgrade kit for $2,500.

Try SWTA in Smithville

[Yetti]

Call a Parker Hanofin dealer

 

https://ph.parker.com/us/en/600-series-stat-o-seal

 

[Yetti]

2 hours ago, JoeM said:

Good advice. Had already done that. Dan said it has been 12 years since he could get this. He recommended a used master cylinder. Of course Mooney offers their upgrade kit for $2,500.

 

 

[EricJ]

3 hours ago, Yetti said:

Call a Parker Hanofin dealer

 

https://ph.parker.com/us/en/600-series-stat-o-seal

 

Many metropolitan areas have a "Parker Store" that sells nearly everything Parker makes.   They will make custom hoses as well.

I needed a stat-o-seal in a pinch a few years back (to rebuild my master cylinder) and our local (actually aviation parts) store near the airport had them.

[tony]

I know this is an old thread.  One of my cylinders is weeping and I'm going to have to give it some attention.  I found this video.  Thought I should share......