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Old 06-26-2021, 06:09 PM
chevytoo chevytoo is offline
Join Date: May 2011
Location: Langley B.C.
Posts: 31
Default Cowl retaining pin

I came back from a flight and there was a large puddle of oil under the engine. I opened the oil door on the upper cowl and saw the right hand pin that holds the cowl in place sitting on the battery. It turns out the pin had shorted between the battery and the oil pressure hose. The hose has a large leak. I obtained new hose and will assemble it and install it soon. Vans drawings do not show a retainer for the pins at the firewall. I know how I will make retainers for both top cowl pins and that will be done after I clean up the oil mess. I lost only 1/2 quart but that does make a big mess. I see the advantage of modifying the cowl attach to 1/4 turn fasteners. I am confident the vertical pins on the side of the firewall will not be a problem.

Last edited by chevytoo : 06-26-2021 at 07:43 PM.
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Old 06-26-2021, 07:00 PM
Scott Hersha Scott Hersha is offline
Join Date: Jan 2005
Location: Cincinnati, OH
Posts: 2,027

You didnít say what model of RV you have, but cowl pins work very well on all RV models that i have seen, even on the top cowl. You just need a cowl pin retainer bracket mounted on the firewall - very easy to make/install. If you have a side by side model, it may be easier to make a small access panel in the aft surface of the top cowl in the center, to access the pins and provide the locking mechanism, but that makes it even easier to remove/install your cowl. The hinge holds the cowling very securely, doesnít pillow if done correctly, and is a fraction of the cost and weight of camlock fasteners.
Iíve used both methods, and I will be using hinges again on my current RV build.
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Old 06-26-2021, 07:49 PM
chevytoo chevytoo is offline
Join Date: May 2011
Location: Langley B.C.
Posts: 31

I have an RV-9A. What you describe as a retainer is what I had figured to make.
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Old 06-27-2021, 12:50 AM
gasman gasman is offline
Join Date: Mar 2007
Location: Sonoma County
Posts: 4,143

I would question the installation of the "pin".

First, If a pin backed out, it would conflict with the left "pin" and would need to bend forward or down to continue to back out of the hinge.

Second, the "pin" is under tension due to the curve of the cowl and is difficult to install and remove by hand. I would say that the "pin" was not properly installed.

If your "pin" slid in and out with ease, then it was the wrong diameter. There is reason most all car manufacturers have a non metallic cover on the + terminal of the battery.

There is a reason Vans drawings do not show a retainer for the "pins" at the firewall.
VAF #897 Warren Moretti
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Old 06-27-2021, 06:03 AM
BH1166 BH1166 is offline
Join Date: Nov 2017
Location: Eatonton Georgia
Posts: 537

Several months ago I inquired as to a Vans design of top pin retention…. someone shared this firewall top pin retainer. I believe this is a part in 14 kits.
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Last edited by BH1166 : 06-27-2021 at 06:05 AM.
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Old 06-27-2021, 08:18 AM
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Walt Walt is online now
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 6,356

I've seen lots of migrated pins, retainers are a good idea especially over the battery.
That situation could have been much worse. A boot on leads also helps prevent this from happening.
Walt Aronow, DFW, TX (52F)

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Old 06-27-2021, 02:03 PM
chevytoo chevytoo is offline
Join Date: May 2011
Location: Langley B.C.
Posts: 31

Thanks for the feedback. I do have boots on the battery terminals. The pin slid under the boot when it fell out. The pin is the diameter per Vans drawings and was fully installed. I like the retainer in the photo and will make one similar. Ray
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Old 06-28-2021, 02:51 PM
WingsOnWheels WingsOnWheels is offline
Join Date: Mar 2009
Location: Plano, TX
Posts: 2,248

I don't have a good picture, but I just added a couple screwes to the firewall with a spacer and washer to for a T. The handle on the pin just goes behind the T under some tension. Easy peasy.
Colin P.
RV-6A #20603
Complete 5/10/19
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Old 06-28-2021, 03:41 PM
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bruceh bruceh is offline
Join Date: Mar 2008
Location: Ramona, CA
Posts: 2,512

Easy retainer fix. Just a small section of aluminum angle riveted to the firewall. Notched out a little slot to hold the ends of the pins.

Bruce Hill
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Old 06-29-2021, 02:48 PM
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avrojockey avrojockey is offline
Join Date: Aug 2019
Location: Appleton, WI
Posts: 423

Great ideas here! My pins walk but then they run into each other and stop. My battery box is in the plans location (far left side of firewall) so not sure if there's a threat of a pin short.
Tim Holmes
Appleton, WI
RV-9A N904DC
2022 Dues Paid
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