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GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
I'm wondering if Gary @Geedee will be with the Collings Foundation tour this year.
What are you doing today? (6 Viewers)
- Thread starter GrauGeist
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Lucky13
Forum Mascot
....enjoying the blue sky, sun, cuppa and Victoria Sponge Cake!
MIflyer
Captain
Well, today I enjoyed one of the most thrilling aspects of owning my own airplane, raising it up so I could top off the MLG shock struts with brake fluid.
By the way, the brakes use hydraulic fluid while the hydraulics use brake fluid.
It is somewhat less thrilling than before because I have switched from jacking up the MLG gear at the knee joints to using an engine hoist to lift the wing at the outer/inner wing joint. The former method was exciting since you never know if it might just decide to fall off the jack or having the jack jam in the UP position. The hoist approach eliminates that concern, although you still have to remember to chock the other wheel to keep it from rolling off somewhere as well as checking to make sure the other wing is not crushing something during its travel toward the floor.
I have switched to DOT5 silicone brake fluid for the shock struts, since it does not absorb water like the DOT3 alcohol-based stuff and thus does not promote corrosion. Of course DOT5 silicone costs about 10 times as much as DOT3. And since the total amount of fluid involved is only about 3 ounces for each side it is not that costly (maintenance manual says 20 ounces per side so maybe they were consuming another form of alcohol when they wrote that). In any case I got out the actual manufacturing drawings, calculated the maximum amount of fluid in the strut, and came up with a tad under 3 OZ.
Unlike DOT3, the DOT5 fluid does not strip the paint off the landing gear. I had one shock when I started to pump some DOT5 into the strut and found out that, rather than the translucent blue stuff I recalled, this DOT5 looked like used motor oil! Horrified, I opened a fresh bottle and found it also looks like motor oil except that it has a purple tone rather than the yellowish tint of the stuff in the pump oiler. I decided to trust the stuff out of the new bottle.
So tomorrow I start putting it all back together.
By the way, did y'all know that alcohol-based brake fluid like DOT 3 originally was known as "Lockheed Fluid" circa WW2? There were two Lockheed brothers, originally spelled more like "Loaghead" which is pronounced "Lockheed." After trying their hands at building a seaplane, with a young chap named Jack Northrup as an employee, one of them stuck with the airplane business (and was never heard of again). The other one developed hydraulic brakes for automobiles and became a rip-roaring success as a result, his handiwork being used in billions of automobiles all over the world - and Ercoupe shock struts.
By the way, the brakes use hydraulic fluid while the hydraulics use brake fluid.
It is somewhat less thrilling than before because I have switched from jacking up the MLG gear at the knee joints to using an engine hoist to lift the wing at the outer/inner wing joint. The former method was exciting since you never know if it might just decide to fall off the jack or having the jack jam in the UP position. The hoist approach eliminates that concern, although you still have to remember to chock the other wheel to keep it from rolling off somewhere as well as checking to make sure the other wing is not crushing something during its travel toward the floor.
I have switched to DOT5 silicone brake fluid for the shock struts, since it does not absorb water like the DOT3 alcohol-based stuff and thus does not promote corrosion. Of course DOT5 silicone costs about 10 times as much as DOT3. And since the total amount of fluid involved is only about 3 ounces for each side it is not that costly (maintenance manual says 20 ounces per side so maybe they were consuming another form of alcohol when they wrote that). In any case I got out the actual manufacturing drawings, calculated the maximum amount of fluid in the strut, and came up with a tad under 3 OZ.
Unlike DOT3, the DOT5 fluid does not strip the paint off the landing gear. I had one shock when I started to pump some DOT5 into the strut and found out that, rather than the translucent blue stuff I recalled, this DOT5 looked like used motor oil! Horrified, I opened a fresh bottle and found it also looks like motor oil except that it has a purple tone rather than the yellowish tint of the stuff in the pump oiler. I decided to trust the stuff out of the new bottle.
So tomorrow I start putting it all back together.
By the way, did y'all know that alcohol-based brake fluid like DOT 3 originally was known as "Lockheed Fluid" circa WW2? There were two Lockheed brothers, originally spelled more like "Loaghead" which is pronounced "Lockheed." After trying their hands at building a seaplane, with a young chap named Jack Northrup as an employee, one of them stuck with the airplane business (and was never heard of again). The other one developed hydraulic brakes for automobiles and became a rip-roaring success as a result, his handiwork being used in billions of automobiles all over the world - and Ercoupe shock struts.
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- #1,404
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
DOT 3 and 4 are glycol based, DOT 2 (which is obsolete) was Mineral oil or Caster oil based.
The "oil" based brake system (later defined as DOT 2) was the first hydraulic braking system patented by Ernest Weight in 1909, seven years before Lockheed's system.
And just a head's up: DOT 5 has a different hydraulic reaction to compression than DOT 3/4.
People who put Silicone fluid in a vintage vehicle's system without upgrades, will find the pedal "spongy" and braking is not as aggressive as it would be with the original DOT 3.
I'm not sure how this will affect the oleo's response when landing, but I thought I'd mention it.
The "oil" based brake system (later defined as DOT 2) was the first hydraulic braking system patented by Ernest Weight in 1909, seven years before Lockheed's system.
And just a head's up: DOT 5 has a different hydraulic reaction to compression than DOT 3/4.
People who put Silicone fluid in a vintage vehicle's system without upgrades, will find the pedal "spongy" and braking is not as aggressive as it would be with the original DOT 3.
I'm not sure how this will affect the oleo's response when landing, but I thought I'd mention it.
N4521U
Plastic Pirate
I don't plan....... it just rears it's ugly head and I have to get thru it best I can!
Greg Boeser
1st Lieutenant
Dreaming up all the things I could do this weekend while the wife is up north with her BFF for the weekend. Oh, sure. I could fix the bathroom ceiling, finish painting the garage, reassemble the patio bench I repainted last year, or any number of tasks on the "honey do" list.
Or I could start working on the CR 32 for GB 70. Or set up a monster game and play all weekend.
Probably spend it doomscrolling.
Or I could start working on the CR 32 for GB 70. Or set up a monster game and play all weekend.
Probably spend it doomscrolling.
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Time is a terrible thing to not waste.
Travelling down to Norfolk to meet up with Terry.
I wish I could be with you together there.
Warspite63
Staff Sergeant
- 1,112
- Dec 8, 2022
Don't forget these words of wisdom: hard work pays off later .... but procrastination pays off RIGHT NOW!. I live by this philosophy
Lucky13
Forum Mascot
Trying my best to keep my sanity....
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SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Brother, you're preaching to the choir.Don't forget these words of wisdom: hard work pays off later .... but procrastination pays off RIGHT NOW!. I live by this philosophy
Viking1066
Brigadier General
It's nice to have absolutely no classes until July 7th.
Warspite63
Staff Sergeant
- 1,112
- Dec 8, 2022
I've been told I have absolutely no class ... ever .... ;-P
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So do we my friend
N4521U
Plastic Pirate
Hmmmmmm...................... what to do? I'll leave it there for now
Greg Boeser
1st Lieutenant
OK. Bathroom ceiling fixed. AC installed in bedroom window. Puttered around in the garden. Some Fighting Wings lined up for this afternoon. Beer chilling in fridge.
N4521U
Plastic Pirate
Having a rum and coke!!!!!
Lucky13
Forum Mascot
Greg Boeser
1st Lieutenant
'Cuz it didn't exist?
