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CJ6 Maintenance question

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threein60(at)yahoo.com
Guest

Posted: Fri Sep 22, 2006 11:57 am Post subject: CJ6 Maintenance question

Question to that maintenance savy out here.   When inflating the main gear of a CJ-6 (or maybe a Yak), with Nitrogen, do you inflate to the stated strut distance in the MM or do you use a gauge that can read 720psi?

   

  Thanks for you input..

  Larry 8181C

Larry Pine



  		Get your email and more, right on the [url=http://us.rd.yahoo.com/evt=42973/*http://www.yahoo.com/preview] new Yahoo.com[/url]   [quote][b]

cjpilot710(at)aol.com
Guest

Posted: Fri Sep 22, 2006 2:37 pm Post subject: CJ6 Maintenance question

I've used pressure.  I wasn't aware there was strut measurement.  

 Jim "Pappy" Goolsby

  [quote][b]

dave(at)davelaird.com
Guest

Posted: Fri Sep 22, 2006 3:01 pm Post subject: CJ6 Maintenance question

I jack the leg up so the wheel is clear of the floor and set the tank  

regulator the desired pressure and then inflate.   I do this because  

the first time I was inflating I messed up and deflated

the leg... the wing gets lower and lower.... Lucky for me I had made  

sure nothing was UNDER the wing so it didn't touch anything and bend  

any metal....



Although I have wondered if I should instead just set the jack to  

just touching the jack point and not lift the wing at all because the  

pressure in the strut might be slightly different with weight of the  

plane on it.



comments?

Dave Laird

N63536  1983 CJ6A  "Betty"

Dallas

Ernie

Joined: 11 Jan 2006
Posts: 513

Posted: Fri Sep 22, 2006 4:59 pm Post subject: Re: CJ6 Maintenance question

If you have the appropriate tool its easy. A lot of people use an adapter which doesnt allow them to measure the existing pressure in the strut. With a proper strut inflation tool, you can measure the correct pressure then fill to spec. The specs are listed in the manuals, I'm sorry but I dont have them handy, but they do specity that you do the inflation while on jacks.



Ernie

pa3arw(at)euronet.nl
Guest

Posted: Sat Sep 23, 2006 4:09 am Post subject: CJ6 Maintenance question

Dave,



It doesn't make any difference whether you put the plane on jacks. The

pressure in the struts remain the same, as in the tires.....Boyle's law....



Hans



-----Oorspronkelijk bericht-----

Van: owner-yak-list-server(at)matronics.com

[mailto:owner-yak-list-server(at)matronics.com] Namens Dave Laird

Verzonden: zaterdag 23 september 2006 1:01

Aan: yak-list(at)matronics.com

Onderwerp: Re: CJ6 Maintenance question






I jack the leg up so the wheel is clear of the floor and set the tank  

regulator the desired pressure and then inflate.   I do this because  

the first time I was inflating I messed up and deflated

the leg... the wing gets lower and lower.... Lucky for me I had made  

sure nothing was UNDER the wing so it didn't touch anything and bend  

any metal....



Although I have wondered if I should instead just set the jack to  

just touching the jack point and not lift the wing at all because the  

pressure in the strut might be slightly different with weight of the  

plane on it.



comments?

Dave Laird

N63536  1983 CJ6A  "Betty"

Dallas

cjpilot710(at)aol.com
Guest

Posted: Sat Sep 23, 2006 4:57 am Post subject: CJ6 Maintenance question

In a message dated 9/23/2006 5:11:05 A.M. Pacific Standard Time,  pa3arw(at)euronet.nl writes:

  

 Hans,

 You are correct about Boyle's law,  however - - -

 To do a complete service of a gear strut, you need to jack up the  airplane.  

 Release all the pressure from the strut. 

 Remove the valve assembly from the strut. 

 Make sure the fluid level in the strut is high enough to flow from the  opening with strut fully extended.  

 Reassemble the valve and pressurize the strut. 

  

 If you know that its just pressure that is down, you are correct, there is  no need to jack up the airplane.

  

 To make life easier you can tap and replace those Chinese valves with  standard US valves.  This makes serving away from home a whole lot  easier.

  

 Jim "Pappy" Goolsby

  

  

  

  	  Quote: 	
		  -->    Yak-List message posted by: "Hans Oortman 1"    <pa3arw(at)euronet.nl>



Dave,



It doesn't make any difference    whether you put the plane on jacks. The

pressure in the struts remain the    same, as in the tires.....Boyle's    law....



Hans



-----Oorspronkelijk bericht-----

Van:    owner-yak-list-server(at)matronics.com

[mailto:owner-yak-list-server(at)matronics.com]    Namens Dave Laird

Verzonden: zaterdag 23 september 2006 1:01

Aan:    yak-list(at)matronics.com

Onderwerp: Re: CJ6 Maintenance    question



--> Yak-List message posted by: Dave Laird    <dave(at)davelaird.com>



I jack the leg up so the wheel is clear of    the floor and set the tank  

regulator the desired pressure and then    inflate.   I do this because  

the first time I was    inflating I messed up and deflated

the leg... the wing gets lower and    lower.... Lucky for me I had made  

sure nothing was UNDER the wing so    it didn't touch anything and bend  

any metal....



Although I    have wondered if I should instead just set the jack to  

just touching    the jack point and not lift the wing at all because the  

pressure in    the strut might be slightly different with weight of the  

plane on    it.



comments?

Dave Laird

N63536  1983 CJ6A   es  Day       -->                - NEW MATRONICS WEB FORUMS -

bsp;    -->  nbsp;                - NEW MATRONICS LIST WIKI -

_-=  ;  p;               - List Contribution Web Site  ;                             =========================



	


 

  

  [quote][b]

pa3arw(at)euronet.nl
Guest

Posted: Sat Sep 23, 2006 6:52 am Post subject: CJ6 Maintenance question

Jim,  

   

The few times I have done the struts on my Yak52 we indeed have put her on jacks, of course, it makes life a lot easier. I also made some tools to fit to the valve because I couldn’t get to original Russian tool. It works fine and has a pressure meter on it as well. Normally we do this about once every 100hours. The oil makes it really messy though…  

   

Fly safe!  

   

Hans  

         

  

Van: owner-yak-list-server(at)matronics.com [mailto:owner-yak-list-server(at)matronics.com] Namens cjpilot710(at)aol.com

 Verzonden: zaterdag 23 september 2006 14:57

 Aan: yak-list(at)matronics.com

 Onderwerp: Re: CJ6 Maintenance question  

  

       

In a message dated 9/23/2006 5:11:05 A.M. Pacific Standard Time, pa3arw(at)euronet.nl writes:  

    

   

    

Hans,  

    

You are correct about Boyle's law,  however - - -  

    

To do a complete service of a gear strut, you need to jack up the airplane.    

    

Release all the pressure from the strut.   

    

Remove the valve assembly from the strut.   

    

Make sure the fluid level in the strut is high enough to flow from the opening with strut fully extended.    

    

Reassemble the valve and pressurize the strut.   

    

   

    

If you know that its just pressure that is down, you are correct, there is no need to jack up the airplane.  

    

   

    

To make life easier you can tap and replace those Chinese valves with standard US valves.  This makes serving away from home a whole lot easier.  

    

   

    

Jim "Pappy" Goolsby  

    

   

    

   

    

   

   	  Quote: 	
		    

--> Yak-List message posted by: "Hans Oortman 1" <pa3arw(at)euronet.nl>

 

 Dave,

 

 It doesn't make any difference whether you put the plane on jacks. The

 pressure in the struts remain the same, as in the tires.....Boyle's law....

 

 Hans

 

 -----Oorspronkelijk bericht-----

 Van: owner-yak-list-server(at)matronics.com

 [mailto:owner-yak-list-server(at)matronics.com] Namens Dave Laird

 Verzonden: zaterdag 23 september 2006 1:01

 Aan: yak-list(at)matronics.com

 Onderwerp: Re: CJ6 Maintenance question

 

 --> Yak-List message posted by: Dave Laird <dave(at)davelaird.com>

 

 I jack the leg up so the wheel is clear of the floor and set the tank  

 regulator the desired pressure and then inflate.   I do this because  

 the first time I was inflating I messed up and deflated

 the leg... the wing gets lower and lower.... Lucky for me I had made  

 sure nothing was UNDER the wing so it didn't touch anything and bend  

 any metal....

 

 Although I have wondered if I should instead just set the jack to  

 just touching the jack point and not lift the wing at all because the  

 pressure in the strut might be slightly different with weight of the  

 plane on it.

 

 comments?

 

 

 Dave Laird

 N63536  1983 CJ6A  es Day   -->             - NEW MATRONICS WEB FORUMS -

 bsp; --> nbsp;             - NEW MATRONICS LIST WIKI -

 Web Site ;                         

 

 

   	
  

    

   

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        [quote][b]

wlannon(at)cablerocket.co
Guest

Posted: Sat Sep 23, 2006 9:28 am Post subject: CJ6 Maintenance question

Jim;

  

 Very true. You should know if the fluid level in the oleo strut is adequate  before topping up the air pressure. However the method you describe for checking  it will overfill the strut to the point where it will no longer function since  it will be full of fluid

  

 The Chinese manual gives a specific volume of fluid which is impossible to  check without fully draining and re-filling. The less accurate but  acceptable method of checking fluid level is much as you describe but with  the oleo's fully collapsed NOT extended. Fill to overflow with the  struts collapsed.

  

 Cheers;

 Walt   

 [quote]   ---

philgower(at)rappsystems.
Guest

Posted: Sun Sep 24, 2006 1:28 am Post subject: CJ6 Maintenance question

Hi, if the airplane's weight is on the strut, the  strut length will be shortened, the space for the gas is reduced and thus  the pressure is higher - surely???

  

 Phil Gower (interested in a Yak  18T)

  

  



  

 

    [quote][b]

cjpilot710(at)aol.com
Guest

Posted: Sun Sep 24, 2006 4:00 am Post subject: CJ6 Maintenance question

In a message dated 9/24/2006 2:29:44 A.M. Pacific Standard Time,  philgower(at)rappsystems.com.au writes:

  	  Quote: 	
		        Hi, if the airplane's weight is on the strut, the    strut length will be shortened, the space for the gas is reduced and thus    the pressure is higher - surely???

    

   Phil Gower (interested in a Yak    18T)



	
   

 With the airplane's weight on the jacks and off the wheels - think of the  pressure in the strut as a "preloaded" pressure.  Yes the pressure  increases when the strut is shorten, but that is the shock  absorbing function of the gas.

  

 Jim "Pappy" Goolsby



  [quote][b]

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