[GMAs]

Hey I thought that a ppt presentation would work out for sending across the web... but....

So here you are... you answer to your question about the Waist gate clean out kit...

If you look at the picture of the actuator in the service manual you will see that it is comprised of a inlet... unfilterd nat... a orfice... where the dirt usually gets stuck in... a piston...a big spring.... and a outlet... which goes to the controler..

Now we have been thru the way the system works before so we won't cover that here... you already know what happens when... so lets just look at the actuator and how to clean it without taking it out...

What you will need....

Your compression checker.. the thing you check your cyc compression/blowdown ... it has a regulator on it as well as a on off air valve...

You will need a clean small paint pot... or some other canister that can stand up to 60 lbs pressure on it... tubing/pipe..etc... and can be filled with a cleaning fluid... stodard solvent, gas.. etc... fire here is the key word... as we are going to creat a enviroment that can be damaging if care is not taken... sort of a risk management kind of things... not to be done in a hangar ...

You will need a couple of fittings with some alu tubing already flaired so that you can attach them to the Outlet of the paint pot... to the OUTLET of the actuator... and some clamps...to keep the hose from blowing off...

and you will need some hose...to connect the thing up... we use tigon hose... some can use nlyon and other may want to use plain old rubber hose... that is clean inside...

How it all goes togeather......

Remove the and clean out the lines from the actuator.. and remove the inlet fitting gaining access to the chamber where the orfice hole is drilled... (note the direction it was facing and the number of threads showing above the locking nut...

You connect your compression tester to the air supply... it then in turn has the on off valve that goes to the regulator... which is set for 60 lbs... not 80 that you use for testing the cyc's... this output then goes to the paint pot or in some cases we have seen them use just a longer piece of tigon tubing that is loaded with gas or cleaning fluid.... the end of the paint pot..(liquid output) is attached to the OUTPUT of the waist gate... so that when we apply the pressure.. we get fluid that is forced backwards into the actuator... which then will flush out the orfice and clean out the piston and cyc area...

Ok you say.. but will that clean it out ... well yes and no....

you have to remove the small inlet fitting on the actuator so that all the dirt can be blown out without any being left in the bottom of the inlet orfice area... otherwise if you didn't take the fitting out.. and it has a o ring on it... so you need to look at 43.13 for how to tighten them back up correctly.... you could have some dirt still stuck in it....

Look but, never try and force a piece of wire down into the orfice... as all you will do is get the dirt piece stuck in the controller and now you will have other problems...

Ok .. why only 60 lbs.... of air pressure.. well your oil system operates on that that most of the time... and when you bring the air on line.. its going to force the piston down to the bottom of the actuator... if you used more pressure you might take the chance of blowing the piston seal... not good... so we limit ourselves to 60 lbs...of air pressure... and let it flow.. till the fluid is all forced thru.. and air is the only thing left coming out... which will dry the cleaning fluid/gas.... and no you can not use anything else... sorry... you will hurt the seals if you do...

When you get done.. look with a inspection mirror down into the actuators inlet... with a light it should look clean... if not repeat the process again...

This should save lots of time for taking the thing appart and putting it back togeather again... sure it makes a mess but, its less time finishing and cleaning the engine with a spray gun than taking the bolts out and removing the actuator...

Now if dirt gets up into the controller.. your on your own... as this is much more than just flushing it thru.... Gary Main down at Main turbo has told me many times at the maintaince meetings that he has seen the skymasters have more problems with wear and dirt in their contollers than just about any other plane... and it seems to wear the control pins... faster...

Here my suggestion is that you take it off and send it to him... as he has the necessary set up tools and shop to do the job... it runs about 500 buck to have one gone thru... and overhauled... so you want to make sure the oil is clean.. another reason we say to use the 25 hr rule... but, others will say thats not economical... OK...

Oh and when you go to put the inlet fitting back in the actuator.. you might want to go look at the part on setting the O ring.... yes their is a special way to do it...

And when done have your mechanic make sure the lines are not twisted, kinked or otherwise... leaking or could leak...

We have found that if you start to get dirt/parts of carbon.. which start to block up the inlet orfice... you might want to pull the plug on the bottom of the accessory case... the big one... along with the oil filter adapter.. and clean out the bottom of the casting... as you can be sure that if their was one speck... of carbon their.. that their are others just waiting... to make the trip down the hose to the actuator.... smile...

runing the engine and keeping the system clean is the best way... change the oil often is the other... and lastly... flying the plane and maintaing it is the last.... the actuators do get plugged up... and we have asked for permission to change the line to the "flitered oil" but, it seems that they are recluant to make any changes...even though the early engines has a tap on the main feed of oil to the engine gally where the oil pressure line attaches...(this was filtered oil)... to many lawyers... I guess... so we have been working on a inline filter assembly that would/could be put on as a STC thing... but, that takes time and with the small few in numbers.. that would need it.... is un-econimically sound.. sorry...

Hope this helps... it would be better if I could show you the pictures of the stuff.. and how we do it... usually takes about 30 min to clean both.. front and rear... and oh ya.. this is a pilot/owner/ helping the mechanic kinda thing... so you do have to have him around.. when you do it.. but, hey he may learn something and not charge you for his time... smile.. GMAs...