1) The plane is on jacks and when I run the free-fall gear test, it
stops before the overcenter link finishes. Pulled the bolt on the
over-center link and all indications are that the Matco hydraulic
cylinder is sticking as everything else swings very free. The kit was
started in ‘91 and started flying in ‘99. I changed out the hydraulic
fluid last year during the annual (the pump plastic tank was splitting.)
and used new bulk fluid, type 41, from Aircraft Spruce. Do the cylinder
seals go bad around this time frame on Matcos? If so, can I get just the
elastomer parts and rebuild myself or is it a factory job only?

2) In a similar vein, it appears the Matco brake pucks are also
sticking. So same question – do they tend to go bad around this time frame?

Charles,

 

I have been flying since 1996 and never had the problems you mention although all of the gear actuators are now Wolstenholme (replacements from AeroCrafters).  I have rebuilt some of them with the rebuild kits from Lancair.

 

I am still using the milspec H5606A fluid from the gallon I got in about 1992.  H5606G (type 41) is slightly different.  See:

 

 

I wonder if the mix of old and new created the problem? OR, if the MATCO seals are rubber based?

 

The rebuild is relative easy (but messy) as long as everything is kept clean, seals are lubricated before sliding everything back and forth and the trapazoidal shaft seals are correctly re-installed.

 

Good Luck,