The Hose Change Experience

[FlyingMonkey]

Having just finished up doing my five year Rotax hose change myself, I thought I'd share my experiences.  First some background:

My condition inspection expired at the end of April, so it was time for that right as I received my inspection rating, and thus could do my own condition inspection for the first time.  I knew that for the past couple of years that my rubber engine mount isolators were questionable.  I had put it off because the engine was not sagging or suffering excessive vibration, but it was definitely time for them to go.  That requires removing the engine from the firewall.  

As long as the engine was coming off anyway, I decided to do the Rotax rubber replacement.  It's not due until 2018, but I don't want to have to pull the engine twice.  I got the list of needed hoses and parts from Roger, and gathered all the materials.  So that is how the story begins.

Overall, I'd say that the job is not crazy difficult.  It's just time consuming, and there are a *lot* of little details to remember as you go.  A notebook really comes in handy.  As does an extra set of hands.  You could do it alone, but there are some things that really, really go faster with two people.

I only had my friend Brian's help for one full day, so I tried to get everything ready by the time he got there.  Things like pulling the muffler and disconnecting the gascolator.  My goal was to get the engine off, replace everything that needed to be replaced with the engine off, and then replace the engine while I had Brian to help me.  The rest I could do on my own.  We managed to get that done, but it was a long day, about 14 hours of straight work.

We did the engine mounts first; here is what we saw externally that made me want to change them:

Pretty terrible, right?  Well...maybe not.  When we pulled them out, they all looked like this:

Not bad at all!  I think the mounts could have soldiered on longer, apparently only the outer areas were cracked from engine heat.  Anyway, they are swapped now and should be good for another hose change interval at least.

We reused the firesleeves and most of the clamps, but replaced any clamps that were questionable, the wrong type, or just looked sketchy.  The previous hose change used the wrong coolant hoses (3/4" automotive hoses instead of the correct 17mm hoses); and because they were slightly oversized many  of the clamp points had second clamps on them.  We fixed all those points, and they all were leak-free after with just the single Rotax spring-type clamps.

We worked methodically, and were very careful to only remove/change *one* hose at a time, and make sure it was reattached and tight before moving on.  We didn't want to leave anything loose, misconnect a fitting, or have other mistakes.  The hoses that attach to the rear of the engine are tough to get to, even when the engine is pulled away from the firewall a good amount.  Plenty of cuss-words and skinned knuckles later, it all got done and we got the engine back on.

I had to take the next day off to let my back rest a bit, since I have a marginal spine anyway and folding myself under that engine all day didn't do it any favors.  The following day I went out and did the top "spider" coolant hoses, they were relatively easy.  I re-checked all hose fittings and routing, and then put the muffler back on.  That is a pain in the butt with only one set of hands, but I got it done and it even aligned will with the cabin heat cowl opening without adjustments.  I went ahead and used all new exhaust springs and safety wired them all.  The takeoff springs will go in my travel kit as field replacement spares.

The part I was most worried about, the oil purge, was a non-event.  I just followed the rotax-owner.com video instructions, and it went exactly as described.  I used 10psi to pressurize the oil tank (the video says 5-14psi), oil pressure came up to 40psi after about 50-60 prop revolutions (I did some extra anyway), and when I checked the lifters they were all hard as a rock and I could not move them at all.

I also did a carb sync, which went very quickly and only took a little adjustment.  The engine ran very smoothly afterwards (duh!).

I flew the airplane around the pattern, three takeoffs and landings, then taxied back and pulled the cowl.  Not a single leak, drip, or problem anywhere.  Yay!   I taxied back to fly it some more, I wanted to put at least an hour or two on it before taking any passengers or making long trips.  At the hold short line for the runway the airplane didn't want to move...flat nose tire!  WTF!!!     So I got to spend some quality time changing the tube in the grass beside the taxiway.  There was a tiny cut in the tube but I had a spare.  By the time I finished up it was late afternoon and I was a bit dehydrated and too tired to fly anymore, so I put her to bed.

The next morning (Sunday/Memorial Day) I went out and flew a solid 1.5 hours, did nine landings, tested WOT and all other engine settings.  It ran perfectly, maybe even a tiny bit cooler than before.  Here are my numbers at 75°F OAT in steady state 5000rpm cruise.  Hard to complain:

So to those who worry about "losing value" by going E-LSA, I would put forward that on just this maintenance cycle of condition inspection plus hose change, I saved approximately $2500.  I have a BRS repack coming up in 2019, and I will surely save a lot there too on removal/reinstall.  From what I have seen so far, I am very confident that I will save at least as much if not more than any possible lost value when I sell my airplane years from now.  In the meantime I can enjoy maintenance on my own schedule, and am free to substitute parts or make modifications free from the LOA/MRA hassle that SLSA owners have to endure (and which I have gone through several times).  So all I can say is:

  

[Doug G.]

E-LSA is not the only way to do it. I did mine since I have an LSRM-A and Rotax training. 

The most difficult things I ran into were 1) like you said, keeping track of everything, and, 2) pulling the exhaust springs (I think these are beefier on the CTLS).

How did you lift your engine? What did you attach to?

Oh, and the BRS is a piece of cake compared to the hose change. You will want your assistant there. Especially when you go to put it back in. It is awkward to lift and see where it needs to align at the same time.

[FlyingMonkey]

Of course Doug, I didn't mean to say there were not other approaches.  Only that I'm happy with my decision to go ELSA and feeling pretty good about the overall financial situation it puts me in.

We used an engine hoist.  Roger recommended we put straps between the cylinders and around the bottom, but we didn't like how that looked like it might interfere getting to some items.  So we put straps around each intake and another under/behind the gearbox.  It balanced very well like that and those areas are plenty beefy for the ~125-130lb of weight.

[sandpiper]

Way to go Andy!! It's a great feeling when it's all done and everything checks out.

[FlyingMonkey]

8 hours ago, sandpiper said:

Way to go Andy!! It's a great feeling when it's all done and everything checks out.

Thanks John!  It was a pretty intimidating amount of maintenance, and by far the most complicated operation I've ever done on my CT.  But like all very complicated tasks, I try to think in terms of:  "How do you eat an elephant?  One bite at a time."

I'd like to get the Maintenance rating down the road, but I'm going to wait a bit and see what shakes out with BasicMed and the LSA market before making the investment.

[Runtoeat]

Thanks for the report Andy.  No better way to know your airplane than to roll up your sleeves and get involved.

[Doug G.]

6 hours ago, FlyingMonkey said:

Thanks John!  It was a pretty intimidating amount of maintenance, and by far the most complicated operation I've ever done on my CT.  But like all very complicated tasks, I try to think in terms of:  "How do you eat an elephant?  One bite at a time."

I'd like to get the Maintenance rating down the road, but I'm going to wait a bit and see what shakes out with BasicMed and the LSA market before making the investment.

Yeah, I have thought about BasicMed, but I am happy with where I am and with the plane. - If I was younger...?

[FlyingMonkey]

26 minutes ago, Doug G. said:

Yeah, I have thought about BasicMed, but I am happy with where I am and with the plane. - If I was younger...?

Same here.  I don't like the "you have to get a medical to fly without a medical" provision.  Plus I'm *very* happy with my CT.  It's hard to imagine a more economical and efficient two seat airplane, and I just about never need "more airplane", or to fly at night or above 10,000ft.

[WmInce]

Way to go Andy . . . well done!

Thank you for updating us on the status of your hose change experience and those pictures.

Regarding your comments on going E-LSA, I agree with everything you said.