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New brake fluid and grease approved by Mooney


KSMooniac

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From Don Maxwell today:

 

Mooney has approved the synthetic brake fluid for use in all Mooney’s.. Royco 782 & Aeroshell 31.  It really needs to be used in any of the Models with the heavy duty dual puck brakes. Those models are the M20K Encore, M20M, M20R, M20S, M20TN, M20U & M20V.

 

Aeroshell has a new grease that has the molybdenum in it that can be used on the Dukes actuators. Aeroshell  64 .

 

 

 

Cold weather starting tip   Prime and wait 30 seconds. Fuel needs time to vaporize.

 

 

 

Please share with other lists .

 

 

 

Don Maxwell

 

dmaxwell@donmaxwell.com

 

 

 

Sent from my LG-US996 using Tapatalk

 

 

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The SB for the Dukes actuator spcifies 10% molybdenum.

From the Aircraft Spruce site:

AeroShell Grease 64
Synthetic Grease for Aircraft Containing Molybdenum Disulfide
An extreme pressure (EP) grease
Meets MIL-G-21164D
P/N 08-00824
Extreme-Pressure Airframe Grease

AeroShell Grease 64 is an EP airframe grease based on the proven lithium thickener technology of AeroShell Grease 33. It can help to extend component life through its exceptional load-carrying and EP properties from fortification using 5% molybdenum disulphide and its excellent wear and corrosion protection. It also helps to reduce the risk of product misapplication by being fully compatible with AeroShell Grease 33. Together, these greases are perfect partners, thereby helping to reduce costs by protecting over 98% of the grease application points on a typical airliner. 

Benefits at a glance

Longer component life through exceptional load-carrying and extreme pressure properties from its formulation with 5% molybdenum disulphide, and excellent wear and corrosion protection1 
Longer grease life from excellent mechanical stability and controlled oil separation1 
Reduced costs through excellent protection and longer grease life1 
Reduced product misapplication risk through complete compatibility with AeroShell Grease 33 
Peace of mind through the use of proven lithium compound thickener technology.  

Attention: Aeroshell greases are now slightly darker in color than before due to new factory formulations.

...has the SB been modified?

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Neat!! Love the A/S #64 idea!! I’ve always thought it was crazy mixing our own grease for that 15%. 

I would caution a willy-nilly switch to mil-83282. Only if needed would be my approach. 

Its a really thin oil. It weeps if things are not perfect in a hydraulic system. Also, switching from std oil to synthetic is a cause of concern for more leaking. 

Just some thoughts from a guy that hates oil leaks.

-Matt

 

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I’m not really good at being first...

Fully synthetic fluids have not been airplane friendly...

But, I am looking forward to somebody else going first with a hydraulic fluid that doesn’t gel over time...

Don’t forget to write a good MS pirep.

Best regards,

-a-

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There is nothing new about the fire-resistant synthetic MIL-PRF-83282. I understand most military aircraft were using it by 1985. It has total compatibility with the oil based 5606. It has other benefits in it's temperature range for stabilizing viscosity over a larger range that is perhaps more applicable to turbo flying up high, but it also last longer in service and is not prone to geling with time in service.
Interesting on the concern for leaks but I have never experienced what might be referred to as premature leaking like we have seen in engines with multi-weight synthetics. Maybe it's a sign that seals are ready for replacement anyway?


Sent from my iPhone using Tapatalk

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An interesting thing occurs with oils and rubber... or seals and Orings....and fuel and plastics...

Some rubber can absorb some oils... this can cause swelling of the rubber based on how much oil it can absorb...

Often a seal will be designed with a specific rubber chemistry to be used, in a specific oil environment... this allows the seal to expand to the right size...  change the oil chemistry, and the balance of the relationship with the rubber may be thrown for a loop...

What I have seen so far, the synthetic oil is not much different in chemistry?  But changing its viscosity will allow it to seep through tiny spaces easier... if those tiny spaces exist already...

 

Applying this to My Mooney experience....

Orings in the fuel caps of my M20C must have been owner produced parts... they absorbed the fuel and grew an inch in circumference... not able to seal out anything...

The weird plastic caps I had were from a race car supply store, and didn’t use a standard o-ring shape either... getting real Mooney gear is a bit more expensive... and a lot more reliable...

If we run into difficulty with this hydraulic oil with our O-rings, There is a good chance that we have a knowledgeable Teflon O-ring guy around here somewhere... Our OSU aviator...

PP thoughts only, not an O-ring guy...

Best regards,

-a-

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That’s what I have always wondered. I’ve had Aeroshell 33MS (now 64)in the shop for a few years now but I’ve never used it on the Dukes actuator because it doesn’t contain the 10% Moly. 

We’ve used the Royco 782 because it’s fully miscible and compatible with  the 5606 which is actually an obsolete part number.  I didn’t know we need permission for that . 

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Without further clarification, I'm going to keep mixing the molybdenum like I've always done.  Why mess with what works?

I'm coming up on doing part A of the AD soon.  In the years I've been doing it, I've never found a measureable degradation of the gear lash.

Mixing the grease/molybdenum is a messy job, but it is cheaper than the newly approved grease.

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  • 10 months later...

I recently replaced O-rings in wheel cylinders and bled the system from the bottom up with 83282 (Aeroshell 31) instead of 5606.  To my surprise the next day both master cylinders were leaking.  The fluid was coming from the actuator rods on both cylinders.  They did have thickened 5606 fluid on them before I started working on the airplane so they had leaked a little in the past just a weep.  Now they are completely shot.   I don't know if it was the synthetic fluid ruining what was left of the ancient seals, the fact the system was empty for month or if the thickened ancient 5606 was too thick to leak appreciably.  I am picking up new O-rings today and can report back.  I don't know if I should fill it back up with Aeroshell 31 or go back to 5606.  The wheel cylinders are not leaking now.  As a side note, the fluid in the wheel cylinders was thick like pancake syrup (maybe not that bad) change your fluid once in a while!  Master cylinder seal numbers for the old black round master cylinders are MS 28775-008, MS 28775-010, MS 28775-111, MS 28775-112.  Need one of each for each cylinder.  I am picking up20191016_190726.thumb.jpg.02a922cd5fa6fbdb111458e18f0d92c6.jpg 3 of each in-case I damage one during installation.  

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FYI...I am in the commercial refrigeration business...when we do refrigeration conversions and we have to change to synthetic oil we find that the "O" rings shrink and leak.  Before you take any system that utilizies mineral oil, you need to question what you are prepared to do if you change to a synthetic oil.

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