Bendix RSA-5 (precision airmotive) pitting in throttle body

NTex · #1 02-17-2014, 10:17 AM

I'm about to send this to Airflow Performance - they did the overhaul in 2012 - but wanted to post this here first and see if anyone's seen anything like this.

Yesterday I was trying to get the mixture cable and arm linkage sorted out yesterday and pulled the servo/FAB from the bottom of the sump.

Then I noticed this:

This is a rebuilt servo that has not been run. The throttle/mixture linkages were manipulated maybe 20 times to get the cable routing figured out, but the engine has never been run (i.e. I can't imagine anything was ingested).

These gouges are deep enough to catch your fingernail. It looks like mechanical pitting vs. chemical because the anodized finish seems to be gouged away - not corroded.?

Anyway, this has me worried. If it's common and no big deal that's great, I just don't know. But if it needs to be fixed I'm wondering how/why this happened.

Chris

Tbone · #2 02-17-2014, 10:38 AM

Looks like moisture corrosion to me.

NTex · #3 02-17-2014, 09:33 PM

Quote:

Originally Posted by Tbone

Looks like moisture corrosion to me.

Well...#(*&!

Is this acceptable, or am I worrying about nothing? Seems like it would be a big deal.

The only fix I can think of is to hone the body and re-anodize it.. aka refurb.

But, why did this thing corrode so badly? Has anyone else noticed something like that?

Tbone · #4 02-18-2014, 04:00 AM

I would send it back to Manufacturer. They would have seen this before. Possibly the finish was applied over a small bit of corrosion. I don't think it is a problem unless corrosion is in air meter or fuel passages.

NTex · #5 02-25-2014, 06:58 PM

Quote:

Originally Posted by Tbone

I would send it back to Manufacturer. They would have seen this before. Possibly the finish was applied over a small bit of corrosion. I don't think it is a problem unless corrosion is in air meter or fuel passages.

They got me sorted out - this was prior corrosion damage (likely caused by a fire extinguisher), and they won't be a problem.

Figured I would close the loop in case anyone else sees anything similar.
Thanks for the replies.