Possible '48 fuel check valve supply

[brianm]

I'm in the process installing the missing fuel pump in my ragwing. While searching for a reasonably priced check valve I spotted these items on eBay: https://www.ebay.com/itm/165189689308

They have a very similar part number to the Parker 475-GG-1/4D, and look very similar based on the photos. Hoof, the manufacturer, seems to supply other hydraulic parts for aircraft. I suspect these are equivalent to the Parker valve, just built by a different supplier. At $15 for two I figured it was worth a shot, especially with the Teledyne 453-1/4S2-6 (superseded part number for the original) going for over $500 new.

[GAHorn]

The original installation instructions have often been overlooked…. but instruct to remove the internal check-valve spring and install the check valve without it.

[voorheesh]

The original installation instructions have often been overlooked…. but instruct to remove the internal check-valve spring and install the check valve without it.

I don’t think this answers the question about whether or not the check valve on EBay would be suitable for installation on a Cessna 170. Unless, reading between the lines, you are saying a check valve is unnecessary due to an installation instruction that sounds like it’s function should be disabled by removal of a spring.

It is a legitimate issue for owners of older aircraft to research available parts and to have some means of identifying approved (safe) versus unapproved (possibly unsafe). Especially considering prices such as the $500 quoted for this case. I think the best answer to the original question would come from the IA who annuals this airplane. That person will sign his or her name to a maintenance record, thus certifying the installation.

[GAHorn]

The original installation instructions have often been overlooked…. but instruct to remove the internal check-valve spring and install the check valve without it.

I don’t think this answers the question about whether or not the check valve on EBay would be suitable for installation on a Cessna 170. Unless, reading between the lines, you are saying a check valve is unnecessary due to an installation instruction that sounds like it’s function should be disabled by removal of a spring.

It is a legitimate issue for owners of older aircraft to research available parts and to have some means of identifying approved (safe) versus unapproved (possibly unsafe). Especially considering prices such as the $500 quoted for this case. I think the best answer to the original question would come from the IA who annuals this airplane. That person will sign his or her name to a maintenance record, thus certifying the installation.

That is NOT what I was saying, Harlow. Without addressing whether or nor that Ebay product is appropriate… … the original check valve had a compression spring inside it…which must be REMOVED at installation….in order for the check valve to function as intended. (If the spring is not removed, gravity cannot be overcome to provide a pump-bypass action should the pump fail. This information was received directly from the Cessna Fuel Systems Engineer.)

BTW, Here is a thread which Bruce created to consolodate discussions about sourcing one of these valves: viewtopic.php?f=24&t=14181&p=133747&hilit=fuel+check+valve#p133642

[voorheesh]

Thanks George, that makes your post a lot more clear, at least for me. An IA friend recently mentioned his worries about owners who buy their own parts between annual inspections and do not record the installations. Then they sometimes forget to mention it to the inspector who is responsible next time around. This IA has no problem assisting owners who work on their own airplanes, but sees room for improvement in communications. The high cost of approved parts is almost always an issue. The original question in this thread sounded possibly like that scenario. The other thread you included should be helpful for figuring out the parts for sale on eBay.

[brianm]

I assure you I have no intention of installing one of these valves on my airplane without getting my IA involved. I'm just taking a chance on buying them because for $15, why not? Maybe they'll work, maybe I'll throw them in the garbage. I just thought others 48 owners might be interested and figured I'd share.

[voorheesh]

I apologize for any inference that the original poster was doing anything improper. There is nothing wrong with making an inquiry like this on a public forum with the experience and knowledge of this association. I was prompted by the question of verifying part numbers when maintaining aging general aviation airplanes. That along with shrinking availability and higher cost can result in mistakes and I was hoping for a conversation on the subject. In my own experience as a 170 owner, I was fortunate to have an IA who would thoroughly search for needed parts and always kept me out of trouble. Hope you get a good answer and don’t have to spend $500 on a check valve.

[brianm]

Update on this. I got my eBay valves in the mail. My mechanic and I cracked one open and the guts are essentially the same as the valve seen here. We removed the spring and he is happy to install it in the airplane. A good outcome and $480 saved.