O rings for Scott 4200 parking brake valve

[Captnmack]

 Was able to remove and service Flap Pump and Valve Assy along with parking brake valve. Took some fine tuning but got it right. Now to observe for any leakage...

[carusoam]

Definitely use caution with steal tools and smooth aluminum sealing surfaces... the hardness differences between the tool and the aluminum can leave a leaky scratch...

Best regards,

-a-

[Captnmack]

9 hours ago, carusoam said:

Definitely use caution with steal tools and smooth aluminum sealing surfaces... the hardness differences between the tool and the aluminum can leave a leaky scratch...

Best regards,

-a-

Next time I’ll get my wooden tools I got from Geaorge Washington....

[carusoam]

Whatever it takes to not have to redo the work... 

 

marauder said you you are good to go with brass...

did GW’s boat have a parking brake? 

-a-

[Prior owner]

Univair is now making what looks like the Scott 4500...I’m going to contact them next week to see if they will sell the valve head separately.

Univair parking brake

[Atalla]

On 1/23/2019 at 8:55 PM, Marauder said:

 

The 4500 kit won’t work for you. Those O rings are much bigger. Aircraft Spruce has the ones you need. I circled the ones you need. Disregard the B in the number.

 

The new guy at Lasar told me the same thing about my brake master cylinder kit and it was the wrong one.

 

Same thing happened to me from Lasar and flap pump rebuild kit.  I will from now on use the parts manual and order exactly the things needed.  I had to combine two rebuild kits (flap pump and brake cylinder) to just get my flap pump back together with only the essential o-rings replaced.  I will end up doing it again as I know I did not replace all that is needed.

[Prior owner]

I talked to Univair this morning- their U-4500A1 parking brake is an exact reproduction of the Scott 4500.

they do not sell the valve head or conical seal separately, but the entire valve stem/head assembly is available for $113.15. 2-3 weeks to get it.

part # U4504A  valve stem assembly

[Captnmack]

19 hours ago, PilotCoyote said:

I talked to Univair this morning- their U-4500A1 parking brake is an exact reproduction of the Scott 4500.

they do not sell the valve head or conical seal separately, but the entire valve stem/head assembly is available for $113.15. 2-3 weeks to get it.

part # U4504A  valve stem assembly

Not a bad price considering...

[MinneMooney]

Can anyone identify this parking brake valve that’s on my ‘65 M20C?

 

[Prior owner]

Definitely not a Scott 4500

[carusoam]

Interesting... the date code looks like a 65 made in the 3rd Q...   a touch late for being placed into many of the 65 Cs...?

Pp thoughts only, not a mechanic.

Best regards,

-a-

[Captnmack]

On 2/3/2019 at 7:59 PM, MinneMooney said:

Can anyone identify this parking brake valve that’s on my ‘65 M20C?

 

That’s a mystery but my guess is an older Cleveland valve...

[MinneMooney]

I just found this image of a Scott 4200. Looks like this might be it.

 

If so, the identifying markings would be on the back side. 

[MinneMooney]

I just took this picture of the back side of my parking brake valve and (although it’s blurry), now I’m wondering if I have a Scott 4500? Or Mfg. XYZ 4500?

Every picture of a Scott 4500 I have seen look like they were machined from aluminum flat stock. Mine obviously started from a casting.

[JamesRussell]

Hi supercop0184:

A little late now - but I found these pages from a '58 Scott parts manual for your 4200 series park brake valve. I have (2) that I'm installing in my Cozy Mk IV.

Hope this helps.

PS: You can cross-over AN O-ring p/ns to M/S p/ns here:

http://spenceraircraft.com/hardware/o-rings-seals-gaskets/ms28775-006-o-ring-packing-preformed-hydraulic-109-119-id-alt-part-an6227b1-an6227-1.html

AN6227-1 = MS28775-006 

AN6227-5 = MS28775-010

Regards,

James

 

 

Scott m:n 4200 park brake valve #2.tiff Scott m:n 4200 park brake valve #1.tiff

Edited February 27, 2021 by JamesRussell
Added files after becoming a member.

[carusoam]

Welcome aboard James.

I’ll see if @Supercop0184 is cruising by, it’s been a while...

Best regards,

-a-

[TCUDustoff]

On 2/3/2019 at 7:59 PM, MinneMooney said:

Can anyone identify this parking brake valve that’s on my ‘65 M20C?

 

 

Sorry for the thread bump, but wanted to share.  I had the exact same question and decided to take mine apart today since it was leaking -- internals are 100% the same as a Scott 4500.  Since the part number for my 68 says 4500A1, and looks like this and not the rectangular body posted earlier, I hypothesize that they were originally cast and switched to machined at some point after the early 68s (I am 68-0008).

Used the o-ring specified in the manual screenshot posted on page one and so far, no leaks with a filled res on my workbench!   I bought a brass dentist pick off amazon per previous poster and, while it took a while, I got the o-ring out and swapped in about 30 min.

Also, for my knowledge, what do you guys and gals put on the AN fuel / hydraulic fittings when putting them back together?  Some sort of anti-seize or sealant?  I'm thinking of the white plumbers tape you use in your house, but know you wouldn't want to use that on an airplane in case it started to come apart and contaminate your system -- do you need anything since the fittings are tapered?  I was going to ask my A&P tomorrow when he helps me put it all back together, but I'm curious what y'all use so I can learn me some

[carusoam]

Compression Fittings are designed to work with no added sealants…

Pipe threads are designed to use Teflon tape… Conical in shape… often marked NPT (national pipe thread)

There is one place where Teflon tape gets used in a Mooney…

But, I forgot what made that unique…. 

 

PP thoughts only, check with your mechanic, or wait for one to arrive here…

Best regards,

-a-

[Shadrach]

Thread bump. I just removed my 4500A. Neither I nor my mechanic have ever rebuilt one.  It was not immediately obvious how the shaft is released from the valve body but I did not spend a lot of time on it.  I have the parts schematic, but cannot find a manual that covers disassembly and reassembly. Any firsthand experience would be greatly appreciated.