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Changing Crush Gasket

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peteohms

Joined: 31 Oct 2007
Posts: 224
Location: Leander, TX

Posted: Fri Jul 25, 2008 3:19 pm Post subject: Changing Crush Gasket

I'm about to do my first oil change on my 912ul.  Instructions call for changing the crush gasket.  Is there a generic gasket available at local auto parts stores?



Pete

jack.kuehn(at)gmail.com
Guest

Posted: Fri Jul 25, 2008 4:13 pm Post subject: Changing Crush Gasket

I don't even remove the plug any more.  I just remove the whole can from the airplane and take the top off, dump out the old oil and clean everything up as clean as new.  Depends on your installation though.  It's actually easier for me to remove the entire sump than to stand on my head and remove the darn plug.  The can needs a good cleaning anyway.  

 

Jack



On Fri, Jul 25, 2008 at 5:19 PM, peteohms <apeterchristensen(at)sbcglobal.net (apeterchristensen(at)sbcglobal.net)> wrote:

 	  Quote: 	
		   --> RotaxEngines-List message posted by: "peteohms" <apeterchristensen(at)sbcglobal.net (apeterchristensen(at)sbcglobal.net)>

 

 I'm about to do my first oil change on my 912ul.  Instructions call for changing the crush gasket.  Is there a generic gasket available at local auto parts stores?

 

 Pete

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=194969#194969

 

 

 

 

 

 

 

 

 

 

 	


 

  [quote][b]

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Fri Jul 25, 2008 5:53 pm Post subject: Re: Changing Crush Gasket

Hi Pete,



Your right that Rotax says to replace the crush washer every time. What I'm about to say is not politically correct, but most people don't replace it every time. Unless it leaks it is still good. Just don't over torque it when you put it back together and smash it. You can use it 3-4 times before replacing the crush washer. Like I said this is against the Rotax manual, but I have never seen one leak that has just been used once.

If you want to replace it now you could probably pick up a crush washer at a motorcycle shop or order one from Lockwood or California Power Systems.

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

hgmckay

Joined: 23 May 2006
Posts: 397

Posted: Fri Jul 25, 2008 6:50 pm Post subject: Changing Crush Gasket

Pete:



Not to my knowledge. The copper crush washers recommended by Rotax should

always be used. Your life is at stake. The Rotax Engines DO NOT LIKE LOSS OF

OIL. Use the recommended crush gasket!! You can get them from Lockwood

Aviation.



Hugh



--

craig(at)craigandjean.com
Guest

Posted: Fri Jul 25, 2008 7:13 pm Post subject: Changing Crush Gasket

You could install one of the quick-drain valves from Saf-air or Curtis and

be done with it. Aircraft Spruce and California Power Systems both carry

them:



http://www.rotaxparts.net/Scripts/prodView.asp?idproduct=1306



http://www.aircraftspruce.com/catalog/eppages/safairsump.php



http://www.aircraftspruce.com/catalog/appages/curtisquickdv.php (scroll to

bottom)



-- Craig

pwmac(at)sisna.com
Guest

Posted: Sat Jul 26, 2008 4:42 am Post subject: Changing Crush Gasket

Now this item is a concern. Add a mechanical gadget that has failure modes out of your control does present life threatening issues. Not very likely, for sure, however I would take a torqued bolt as the safest way to go even with out the crush washer.

 Paul

 ===============

 At 09:10 PM 7/25/2008, you wrote:

 [quote]--> RotaxEngines-List message posted by: "Craig Payne" <craig(at)craigandjean.com>



 You could install one of the quick-drain valves from Saf-air or Curtis and

 be done with it. Aircraft Spruce and California Power Systems both carry

 them:



  http://www.rotaxparts.net/Scripts/prodView.asp?idproduct=1306



  http://www.aircraftspruce.com/catalog/eppages/safairsump.php



  http://www.aircraftspruce.com/catalog/appages/curtisquickdv.php (scroll to

 bottom)



 -- Craig[b]

pwmac(at)sisna.com
Guest

Posted: Sat Jul 26, 2008 4:42 am Post subject: Changing Crush Gasket

Boy what a gross exaggeration. O\If the bolt is torqued it just wont come out - period. Every car manufacturer says the same thing as Rotax. We have been ignoring that forever. What happens is one gets some weeping. No big deal. Don't worry about it.

 Paul

 =================

 At 08:51 PM 7/25/2008, you wrote:

 [quote]--> RotaxEngines-List message posted by: "Hugh" <hgmckay(at)bellsouth.net>



 Pete:



 Not to my knowledge. The copper crush washers recommended by Rotax should

 always be used. Your life is at stake. The Rotax Engines DO NOT LIKE LOSS OF

 OIL. Use the recommended crush gasket!! You can get them from Lockwood

 Aviation.



 Hugh[b]

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Sat Jul 26, 2008 7:30 am Post subject: Re: Changing Crush Gasket

Hi Jack,



Just a note.

If you are flying an ELSA then the quick drain valve is certainly not a bad way to go. If you are SLSA you need an approval from the MFG. I don't believe Rotax sanctions the quick drain valve. We have tried to get them in use for the Flight Design CT, but the FD won't sign off on it because Rotax wouldn't. If you are registered ELSA you can do anything you want. That being said Rotax has it's own warranty items they like or dislike. 

This is one of those discussions that you have to personally decide. 

The book says new crush washer. The experience in the field says it is ok to reuse it a few times. The majority don't change out the crush washer and don't have any problems.



Up to you now to decide.

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

peter.rees01(at)tiscali.c
Guest

Posted: Sat Jul 26, 2008 10:56 am Post subject: Changing Crush Gasket

Why not just buy a new one? At UK fuel prices, if  you fun on Mogas, you're going to burn about 900GBP of fuel per oil change  (based on 15l/h, 50hr service and 1.20GBP per litre (ocuh!)) - I think that the  washers are about 1GBP or less. Same goes with the oil filter - why try and find  an alternative to the Rotax part - its only about 5GBP or so - is your engine /  life really worth risking to save 6GBP??? 

  

 Peter

    [quote][b]

peteohms

Joined: 31 Oct 2007
Posts: 224
Location: Leander, TX

Posted: Sat Jul 26, 2008 1:21 pm Post subject: Changing Crush Gasket

Jack,

  

 That's exactly what I did.  I just removed the whole can and I  found out that there is NO drain plug on my Kitfox III.  So that's  what I had to do.  Next time I think I'll just suck out all of the oil  from the reservoir through the pickup line and call it good.  I'll probably  shorten the oil change time to make up for not getting all the oil.

  

 Thanks to all who responded!

  

 Pete

 Hell Paso, TX

 Kitfox III SN 1000, 912ul

  

  

 [quote]   ---

_________________
Pete
Leander, TX
Kitfox III, 912ul, Grove

thilo.kind(at)gmx.net
Guest

Posted: Sat Jul 26, 2008 2:26 pm Post subject: Changing Crush Gasket

Hi Paul,  

   

that statement is not entirely correct. A bolt will come out, even, when properly torqued – especially at airplanes due to the vibrations. Torquing only makes sure, that the bolt is loaded with the proper tension required for the connection. To avoid loosening of a bolt, several methods are available such as safety wiring, stop nuts, Locktite, etc. The oil release bolt should be safety wired – otherwise the bolt will come loose eventually. Not a good in-flight experience.  

   

The function of the crush washer is to seal the opening. Threats / bolts provide no seals, so liquids – in this case oil – will leak. The crush washer is made from copper. The soft copper metal is pressed by the bolt to the engine house. Due to the pressure the surface of the copper washer deforms to comply with the surface of the bolt and the engine housing, respectively, and hence acts as a seal. Since the surface is deformed after one use, a new washer should be used whenever the bolt was removed.  

   

Best regards  

   

Thilo Kind  

Zodiac CH 601 HDS with Rotax 912 flying  

RV 8A under construction  

         

  

From: owner-rotaxengines-list-server(at)matronics.com [mailto:owner-rotaxengines-list-server(at)matronics.com] On Behalf Of paul wilson

 Sent: Samstag, 26. Juli 2008 14:32

 To: rotaxengines-list(at)matronics.com

 Subject: RE: RotaxEngines-List: Changing Crush Gasket  

  

   

Boy what a gross exaggeration. O\If the bolt is torqued it just wont come out - period. Every car manufacturer says the same thing as Rotax. We have been ignoring that forever. What happens is one gets some weeping. No big deal. Don't worry about it.

 Paul

 =================

 At 08:51 PM 7/25/2008, you wrote:

 

   

--> RotaxEngines-List message posted by: "Hugh" <hgmckay(at)bellsouth.net>

 

 Pete:

 

 Not to my knowledge. The copper crush washers recommended by Rotax should

 always be used. Your life is at stake. The Rotax Engines DO NOT LIKE LOSS OF

 OIL. Use the recommended crush gasket!! You can get them from Lockwood

 Aviation.

 

 Hugh   	  Quote: 	
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        [quote][b]

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Sat Jul 26, 2008 3:15 pm Post subject: Re: Changing Crush Gasket

I knew this was going to be a hot topic. 

The drain screw gets 18.5 ft/lbs or 222in/lbs of torque.

Whether you use the old one or a new one it needs to be safety wired. 



We could discuss topics like these for days and it will eventually come down to just you to determine "Do I like Ford's or do I like Chevy's. 

You can't go wrong if you follow the book.

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

pwmac(at)sisna.com
Guest

Posted: Sat Jul 26, 2008 6:24 pm Post subject: Changing Crush Gasket

You are repeating what all manufacturers say. In the real world its no big deal. Our race trucks seldom get a new washer and when we do its never copper its dead soft aluminum.  Never had a leak an never heard of  the bolt falling out. Been doing this to many years and so we know its no sweat. Bolts fall out at the quick lube place because they are installed finger tight.

 If you think the vibration is bad in an airplane check out the vibration on an off road race truck. We lockwire on a lot of fasteners but the drain bolt is just torqued.

 Paul

 ================

 At 04:24 PM 7/26/2008, you wrote:

 [quote]Hi Paul,

  

 that statement is not entirely correct. A bolt will come out, even, when properly torqued – especially at airplanes due to the vibrations. Torquing only makes sure, that the bolt is loaded with the proper tension required for the connection. To avoid loosening of a bolt, several methods are available such as safety wiring, stop nuts, Locktite, etc. The oil release bolt should be safety wired – otherwise the bolt will come loose eventually. Not a good in-flight experience.

  

 The function of the crush washer is to seal the opening. Threats / bolts provide no seals, so liquids – in this case oil – will leak. The crush washer is made from copper. The soft copper metal is pressed by the bolt to the engine house. Due to the pressure the surface of the copper washer deforms to comply with the surface of the bolt and the engine housing, respectively, and hence acts as a seal. Since the surface is deformed after one use, a new washer should be used whenever the bolt was removed.

  

 Best regards

  

 Thilo Kind

 Zodiac CH 601 HDS with Rotax 912 flying

 RV 8A under construction

  

  

 From: owner-rotaxengines-list-server(at)matronics.com [ mailto:owner-rotaxengines-list-server(at)matronics.com (owner-rotaxengines-list-server(at)matronics.com)] On Behalf Of paul wilson

 Sent: Samstag, 26. Juli 2008 14:32

 To: rotaxengines-list(at)matronics.com

 Subject: RE: Changing Crush Gasket

  

 Boy what a gross exaggeration. O\If the bolt is torqued it just wont come out - period. Every car manufacturer says the same thing as Rotax. We have been ignoring that forever. What happens is one gets some weeping. No big deal. Don't worry about it.

 Paul

 =================

 At 08:51 PM 7/25/2008, you wrote:



 --> RotaxEngines-List message posted by: "Hugh" <hgmckay(at)bellsouth.net>



 Pete:



 Not to my knowledge. The copper crush washers recommended by Rotax should

 always be used. Your life is at stake. The Rotax Engines DO NOT LIKE LOSS OF

 OIL. Use the recommended crush gasket!! You can get them from Lockwood

 Aviation.



 Hugh

 

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http://www.matronics.com/contribution[/b] 	
 

 [b]

thilo.kind(at)gmx.net
Guest

Posted: Sat Jul 26, 2008 10:54 pm Post subject: Changing Crush Gasket

Hi Paul,  

   

on a car it’s not a big deal, because the vibrations are different (not uniform) due to always changing RPM setting and induced non-uniform vibrations from the un-even road. This reduces the tendency for bolts to loosen. Airplanes run at almost constant RPM settings, which results in a very uniform vibration. Fasteners will definitely come loose and therefore should be properly secured.  

   

There are two reasons for the replacement of the crush washer: the deformation of the surface after first use and work hardening of the copper as well as many aluminium alloys after exposure to vibrations. This can result is breaking of the crush washer. That’s why good practice dictates to replace the crush washer every time.  

   

I admit, that in a car both the safety-wiring of the bolt and the replacement of the crush washer could be overkill – worst that can happen to you is that the car stops at the shoulder of the raod. In an airplane, this is an entirely different story… That’s why all the manufacturers as well as the FAA recommend / insist on those measures. It is definetly not a money making deal of manufacturers – they are not make a lot of money on a piece of safety wire and a copper washer….  

   

Thilo Kind  

         

  

From: owner-rotaxengines-list-server(at)matronics.com [mailto:owner-rotaxengines-list-server(at)matronics.com] On Behalf Of paul wilson

 Sent: Sonntag, 27. Juli 2008 03:31

 To: rotaxengines-list(at)matronics.com

 Subject: RE: RotaxEngines-List: Changing Crush Gasket  

  

   

You are repeating what all manufacturers say. In the real world its no big deal. Our race trucks seldom get a new washer and when we do its never copper its dead soft aluminum.  Never had a leak an never heard of  the bolt falling out. Been doing this to many years and so we know its no sweat. Bolts fall out at the quick lube place because they are installed finger tight.

 If you think the vibration is bad in an airplane check out the vibration on an off road race truck. We lockwire on a lot of fasteners but the drain bolt is just torqued.

 Paul

 ================

 At 04:24 PM 7/26/2008, you wrote:

 

   

Hi Paul,

  

 that statement is not entirely correct. A bolt will come out, even, when properly torqued – especially at airplanes due to the vibrations. Torquing only makes sure, that the bolt is loaded with the proper tension required for the connection. To avoid loosening of a bolt, several methods are available such as safety wiring, stop nuts, Locktite, etc. The oil release bolt should be safety wired – otherwise the bolt will come loose eventually. Not a good in-flight experience.

  

 The function of the crush washer is to seal the opening. Threats / bolts provide no seals, so liquids – in this case oil – will leak. The crush washer is made from copper. The soft copper metal is pressed by the bolt to the engine house. Due to the pressure the surface of the copper washer deforms to comply with the surface of the bolt and the engine housing, respectively, and hence acts as a seal. Since the surface is deformed after one use, a new washer should be used whenever the bolt was removed.

  

 Best regards

  

 Thilo Kind

 Zodiac CH 601 HDS with Rotax 912 flying

 RV 8A under construction

        

  

From: owner-rotaxengines-list-server(at)matronics.com [ mailto:owner-rotaxengines-list-server(at)matronics.com (owner-rotaxengines-list-server(at)matronics.com)] On Behalf Of paul wilson

 Sent: Samstag, 26. Juli 2008 14:32

 To: rotaxengines-list(at)matronics.com

 Subject: RE: Changing Crush Gasket

  

 Boy what a gross exaggeration. O\If the bolt is torqued it just wont come out - period. Every car manufacturer says the same thing as Rotax. We have been ignoring that forever. What happens is one gets some weeping. No big deal. Don't worry about it.

 Paul

 =================

 At 08:51 PM 7/25/2008, you wrote:

 

 --> RotaxEngines-List message posted by: "Hugh" <hgmckay(at)bellsouth.net>

 

 Pete:

 

 Not to my knowledge. The copper crush washers recommended by Rotax should

 always be used. Your life is at stake. The Rotax Engines DO NOT LIKE LOSS OF

 OIL. Use the recommended crush gasket!! You can get them from Lockwood

 Aviation.

 

 Hugh   	  Quote: 	
		   	
  

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        [quote][b]

grahamsingleton(at)btinte
Guest

Posted: Sun Jul 27, 2008 9:52 am Post subject: Changing Crush Gasket

Paul

Thilo is right, and there's another good reason for using new crush 

washers, this is not a drain plug and solid, it's a banjo bolt. Over 

torque it and it will stretch or break, also the barrel.will deform and 

no longer be flat.

The crush washers are oval section so they easily deform when new to 

form a seal. It takes too much torque to deform them when they are 

already crushed. Not wise to try and vent a well designed wheel 

Graham



Thilo Kind wrote:

 	  Quote: 	
		  

 Hi Paul,



 I admit, that in a car both the safety-wiring of the bolt and the 

 replacement of the crush washer could be overkill – worst that can 

 happen to you is that the car stops at the shoulder of the raod. In an 

 airplane, this is an entirely different story… That’s why all the 

 manufacturers as well as the FAA recommend / insist on those measures. 

 It is definetly not a money making deal of manufacturers – they are 

 not make a lot of money on a piece of safety wire and a copper washer….



 Thilo Kind



 ------------------------------------------------------------------------



 *From:* owner-rotaxengines-list-server(at)matronics.com 

 [mailto:owner-rotaxengines-list-server(at)matronics.com] *On Behalf Of 

 *paul wilson

 *Sent:* Sonntag, 27. Juli 2008 03:31

 *To:* rotaxengines-list(at)matronics.com

 *Subject:* RE: Changing Crush Gasket



 You are repeating what all manufacturers say. In the real world its no 

 big deal. Our race trucks seldom get a new washer and when we do its 

 never copper its dead soft aluminum. Never had a leak an never heard 

 of the bolt falling out. Been doing this to many years and so we know 

 its no sweat. Bolts fall out at the quick lube place because they are 

 installed finger tight.

 If you think the vibration is bad in an airplane check out the 

 vibration on an off road race truck. We lockwire on a lot of fasteners 

 but the drain bolt is just torqued.

 Paul

lucien

Joined: 03 Jun 2007
Posts: 721
Location: santa fe, NM

Posted: Sun Jul 27, 2008 11:45 am Post subject: Re: Changing Crush Gasket

My .02,



If I have a crush washer on me when I do my oil change, I replace it. I'll reuse old ones, tho. Copper will harden a bit once it's crushed so a used washer isn't as pliable as it was (besides already being flat as a pancake).



But at the specified torque (195 in/lbs I believe?, can't remember off top of my head), the drain plug usually still gets a good seal and doesn't leak.



And yes, I wouldn't even consider not safety-wiring the drain plug after installation new crush washer or no....... yeah it's extremely unlikely a properly torqued plug could come out but the wire reduces that probability to as close to zero as you can reasonably get for just a little bit of effort 



LS

_________________
LS
Titan II SS

ptag.dev(at)tiscali.co.uk
Guest

Posted: Sun Jul 27, 2008 11:49 pm Post subject: Changing Crush Gasket

Hi! Lucien

Just to explore the topic further ...whilst I would never advocate not

changing the crush washer.... if it is a solid copper ring and you have

forgotten to have a replacement on hand then it would be best to refit

it after you have annealed it .....heated it cherry red and quenching it

in oil.(the opposite to hardening steel!) That will restore it's

flexibility to reuse. However many crush washers are made of light gauge

copper and are rolled and so folded to allow the crush to take place

(like on ignition plugs) these would not be suitable for annealing.  I

have a 1936 Velocette OHC 350cc motor cycle and it's head gasket is a

solid copper ring about 3" diameter which I have never renewed but

always annealed without ever leaking

Regards

Bob Harrison. Europa G-PTAG 914 Rotax.



--

peteohms

Joined: 31 Oct 2007
Posts: 224
Location: Leander, TX

Posted: Tue Jul 29, 2008 2:38 pm Post subject: Changing Crush Gasket

Jack,

  

 Do you have to then purge the oil  system?

  

 Pete

 [quote]   ---

_________________
Pete
Leander, TX
Kitfox III, 912ul, Grove

jack.kuehn(at)gmail.com
Guest

Posted: Tue Jul 29, 2008 5:00 pm Post subject: Changing Crush Gasket

Pete,

I have not purged exactly as the Rotax video and documentation says you should, but I am going to start doing it.  I didn't really understand the process until I saw the video they posted at the Rotax web site.  Until now I have made sure the oil line to the thermostat and oil cooler and oil pump were full, and removed spark plugs and simply turned the engine a bunch by hand, then with the starter until I get oil pressure on the guage.  Next time I will apply air pressure and check the lifters as recommended.  May be overkill, but it's an expensive engine and deserves the best of care!!  And I would prefer that it not stop running at the wrong moment!

 

Jack



On Tue, Jul 29, 2008 at 3:35 PM, Pete Christensen <apeterchristensen(at)sbcglobal.net (apeterchristensen(at)sbcglobal.net)> wrote:

[quote]        Jack,

  

 Do you have to then purge the oil  system?

  

 Pete

 [quote]   ---

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