Condition Inspection Item - Radiator Hose Abrasion

Working on the Condition Inspection. See the photo. The hose from the top of the radiator to the reservoir is resting on the engine mount and abrading. You can see the rubber smudges on the mount. Maybe a mil is worn on the underside of the radiator line.

Some type of clamp will be required to hold the hose in position. Ideas?



And before anyone notices, I had to remove the engine mount bolt on the left/top to relieve the washer, as it was in contact with the mount as mentioned in a previous post. The top/right was OK. The two bottom washers are close but also OK.

my .02 cents--

make a stand-off bracket to keep a NEW hose from contacting anything. If you allow something like a hose, or a piece of tubing to rub itself on a engine mount tube, it "could" wear enough to weaken the mount in that area. I'm not saying it will, 'cause I wouldn't want to find out. Least that could happen is wear a hole in a hose. Worst---I dont want to go there-----
Tom

Stand off or add a little RTV and stick the hose to it and let it cure.

The subject of engine mounts and things touching them has been a big topic of discussion on VAF and amongst several builder buddies.

I know the judges at OSH this year were very sensative to tie wraps directly attached to the engine mount (like the white one behind the black hose in the pic). We can go round and round about it. I concluded (pre-OSH) it wasn't a big deal since I would be checking it fairly often. I then decided to change it because the judges said the FAA is being very headstrong about it not being an acceptable "technique."

I went to the Lowe's/Home Depot aviation store and picked up some clear tubing that had the same inside diameter as the engine mount's outside diameter. Then I used the tie wraps for securing, standoffs, etc as normal. It looks great and it will definitely hard cushion the mount so the ties don't "saw" or "eat" into the mount (maybe just into the tube -- yet TBD). That would be my suggestion, but like everything else, you'll get 10 suggestions and you have to figure out what you'll be happy with. Dave

I have this "problem," if it is a problem. At the suggestion of VAF, I went up and over the right-angle oil filter. It's impossible to take that route and NOT rub against the engine mount. A stand-off in this configuration does not seem entirely possible because it would require about a 1" clearance once everything is installed, you could only lift the hose higher, and that's going to put a kink in the hose itself. Note on the left side after it clears the oil filter that there is a stand-off with the engine mount.

The hose is "pinched" (with acceptable diminishing of the hose diameter) with the oil filter.

What if I just wrap a bunch of electrical tape around the engine mount there and let it rub against that and just change it -- if need be -- at oil change time?

db8 said:

I went to the Lowe's/Home Depot aviation store and picked up some clear tubing that had the same inside diameter as the engine mount's outside diameter. Then I used the tie wraps for securing, standoffs, etc as normal. It looks great and it will definitely hard cushion the mount so the ties don't "saw" or "eat" into the mount (maybe just into the tube -- yet TBD). That would be my suggestion, but like everything else, you'll get 10 suggestions and you have to figure out what you'll be happy with. Dave

Click to expand...

I did something similar when tying up the blast tube from the back of the baffling to the magneto. I had a piece of firesleeve so I cut it, wrapped it around the engine mount and tie-wrapped it to that.

I like to use Uni-Wrap silicone tape for preventing chafing, it's high temp, bonds to itself and long wearing. I will not tie wrap directly to engine mount without some silicone tape around the mount.

http://www.aircraftspruce.com/catalog/appages/uniwrap.php

Awesome, Walt! I'm adding that to my cart. Thanks!

Clamp...

A simple blob of high quality silicon will hold them in place and stop the chaffing? It is highly effective, and inexpensive. It doesn't look bad either if you do it cleanly? its a good idea for holding a lot of wires and hoses in place so they don't vibrate or rub when there isn't room for a clamp?

Wal-Mart has this stuff called "rescue tape" - peel-and-stick- it is mentioned in several other posts. It sticks to itself, not to other stuff, and cures tough. I wrap it around the motor mounts and put tie-wraps over it, not on the bare mount.

Yes. I have used the rescue tape around scat tubing with tie wraps and wire bundles with tie wraps . I decided not to use it on the engine mount because the tie wraps are generally tighter there and might have more of a tendancy to cut into the tape (though I don't know). It sounds like guys have been using it with no problems. I do know the clear tubing so far has held up very well and is very tough. Dave

For the idea of a soft layer around the engine mount tube, just be sure that your material can withstand the heat. Likewise, if you're using a dab of silicone, use the high-temp kind.

I used some non-heat-resistant spiral wrap around some wires on a different plane, and the stuff melted. Unfortunately the melted and cooled material was difficult to remove.

The max heat usually occurs sometime after shut-down.

Dave

maybe-

for those that want to wrap tape around the mount---use Firesleeve tape. High temp, self adhesive, and with layers, should protect the mount and the hose.

MartySantic said:

Some type of clamp will be required to hold the hose in position. Ideas?

Click to expand...

There's three MS21919-series ideas within your photo...
I'm one of those people here on VAF that says the bare ziptie on your engine mount needs to go, too.