• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

Oil pressure????

flynlow

FRIEND
Fowler, Ks
1798 hours on 0-290. This engine has always pumped 30lbs at idle and 78 lbs at any rpm over 1700.

Last week I noticed 55 lbs at cruise and after landing It showed 15 lbs at 500 rpm idle.

I thought maybe debri under ball and spring or gauge problem. I changed oil and the screen was clean except for very small amount of carbon.

I put a mechanical gauge on port by screen and it showed 80 lbs of pressure with 80 degreetemp oil while the gauge showed 50 lbs. Ok bad gauge, I was going to call Wag Aero and invest in a new gauge Monday.

This afternoon I cranked up the cub and was going to confirm the pressures with hot oil...Now everything is back to normal 30+ lbs at 500 rpm and 78 lbs pressure at 1700 rpm with 180 degree oil. ????????????

? crud in oil line to gauge?? any thoughts?
 
Yeah. You lucky guy. My oil pressure took a dive, and today I hung the new "stroker". I am expecting to see a broken center main web.

One time long ago 30 miles east of Amarillo the Cub oil press went to zero. Zero! As I reduced power and picked out a cow pie for landing, it came back! Never did that again!
 
Did you check the oil pressure relief valve?

No, i was going to next but since my mechanical gauge plugged into the port on the screen housing showed good pressure I decided I had a gauge problem.

I visited with a friend A&P and his theory was the pressure gauge gears slipped a cog and showed low pressure....then as the cub was sitting in the hangar with zero oil pressure with the needle resting on the peg, the gears popped back in the original cog showing normal ops.
Makes sense..so iam still in the market for a new gauge...this one has served since 1951 so it's time.

Yeah Bob I had a RV6 that suddenly went to zero, I pulled power and put it down on a 'lonely' country road and called my 'wrench'.. He put the hose on the engine and it showed good pressure...it was a electrical connection on the back of the gauge from the sender... Lucky me.
 
I visited with a friend A&P and his theory was the pressure gauge gears slipped a cog and showed low pressure....then as the cub was sitting in the hangar with zero oil pressure with the needle resting on the peg, the gears popped back in the original cog showing normal ops.
Makes sense..

:pop:
 
I would send it to the John Wolfe Company and get it fixed. The e ones are made in China and not certified and junk. I have some originals but would be cheaper to get yours repaired.
 
I checked with Air Parts of Lockhaven..$480 with no capillary...$787.50 with dials and capillary. They were 40 days out on getting it repaired.

I'll check with John Wolfe Company...thanks Steve. Do you know anything about Kelleys in Wichita?
 
.... I had a RV6 that suddenly went to zero, I pulled power and put it down on a 'lonely' country road and called my 'wrench'.. He put the hose on the engine and it showed good pressure...it was a electrical connection on the back of the gauge from the sender... Lucky me.
This is why I always prefer a direct reading oil PRESSURE gauge. Oil pressure is the one most important instrument in the airplane. Everything else can be electric since they produce only nice to know information. Direct reading is also the least expensive.
 
Wag Aero sells a dual oil pressure/ temperature gauge p/n A-038-000. It is not TSO'd and I am unsure if the oil pressure function is electric or direct. Have been considering installing this gauge on my PA-12. I have noticed on Barnstormers.com the -12's listed for sale over half have this gauge installed in place of the old cub original. Anyone out there have any experience with this gauge?
 
I would send it to the John Wolfe Company and get it fixed. The e ones are made in China and not certified and junk. I have some originals but would be cheaper to get yours repaired.

I called John Wolfe. He estimated $170.00 and 2 weeks lag. Will pull gauge this afternoon

Steve
 
Wag Aero sells a dual oil pressure/ temperature gauge p/n A-038-000. It is not TSO'd and I am unsure if the oil pressure function is electric or direct. Have been considering installing this gauge on my PA-12. I have noticed on Barnstormers.com the -12's listed for sale over half have this gauge installed in place of the old cub original. Anyone out there have any experience with this gauge?

There is a J3 here that has one of those gauges installed. The temperature started reading incorrectly. It had jumped a cog, and John Wolfe was able to fix it. If the plane was mine I would have changed to two separate instruments but the owner wanted the dual gauge even if it's not exactly correct for the period. Not electric. Is it even legal in a certified aircraft since it has no approval?? jrh
 
I would have to check with my I.A., There may be some Form? etc. that would need to be completed. Is the gauge made overseas?
 
I would have to check with my I.A., There may be some Form? etc. that would need to be completed. Is the gauge made overseas?

W-A answered the question with their code system.
Code 8 To our knowledge, these items do not carry an FAA/PMA, TSO, and/or STC, and no application is in process. These products are offered for sale only for experimental category aircraft.
 
W-A answered the question with their code system.
Code 8 To our knowledge, these items do not carry an FAA/PMA, TSO, and/or STC, and no application is in process. These products are offered for sale only for experimental category aircraft.

Just for fun I checked the PA-12's for sale on Barnstormers.com tonite and found that there are 9 photos of instrument panels shown with the various sellers' listings and of the 9, five have the Wag Aero gauge in question. How does that happen? I too have seen the code descriptions in the W.A. catalog. Nice gauge, why does no one have a TSO'd model?
 
Are TSO gauges required in a 1949 airplane? A fed once told me my Air Force seat belts were ok.

What regulation requires a TSO/PMA oil pressure gauge in a CAR 3 privately operated airplane? Was there such a thing as TSO/PMA instruments in the 1940s?

I understand why catalog retailers print generic approval disclaimers but I don't understand why owners perceive them as limitations.
 
Last edited:
What regulation requires a TSO/PMA oil pressure gauge in a CAR 3 privately operated airplane? Was there such a thing as TSO/PMA instruments in the 1940s?

I understand why catalog retailers print generic approval disclaimers but I don't understand why owners perceive them as limitations.

I wonder if the installation of non TSO'd instruments would require some type of 337 form and a field approval? I would think that as many of these that are in use someone has been through the legal process for their certified aircraft. Having said that, I think that all of these older classic aircraft have modified their current panels as none seem to have the stock factory configurations , so that leads me to believe there is some guideline to legally proceed.
 
What regulation requires a TSO/PMA oil pressure gauge in a CAR 3 privately operated airplane? Was there such a thing as TSO/PMA instruments in the 1940s?

I understand why catalog retailers print generic approval disclaimers but I don't understand why owners perceive them as limitations.



§ 3.18 Approval of materials, parts, processes, and appliances.

(a) Materials, parts, processes, and appliances shall be approved upon a basis and in a manner found necessary by the Administrator to implement the pertinent provisions of the Civil Air Regulations. The Administrator may adopt and publish such specifications as he finds necessary to administer this regulation, and shall incorporate therein such portions of the aviation industry, Federal, and military specifications respecting such materials, parts, processes, and appliances as he finds appropriate.

NOTE: The provisions of this paragraph are intended to allow approval of materials, parts, processes, and appliances under the system of Technical Standard Orders, or in conjunction with type certification procedures for an airplane, or by any other form of approval by the Administrator.

(b) Any material, part, process, or appliance shall be deemed to have met the requirements for approval when it meets the pertinent specifications adopted by the Administrator, and the manufacturer so certifies in a manner prescribed by the Administrator.
 
That requires a better lawyer than me. How about AC 23-27?

We could easily ground over half the Cubs by requiring paperwork for gauges. My personal Cub still has its original compass and altimeter - no TSO. I would have a difficult time proving the factory installed them. In fact, my USG combo has no TSO or paperwork. It came out of a wrecked duster in 1962. Still works!
 
Just for fun I checked the PA-12's for sale on Barnstormers.com tonite and found that there are 9 photos of instrument panels shown with the various sellers' listings and of the 9, five have the Wag Aero gauge in question. How does that happen? I too have seen the code descriptions in the W.A. catalog. Nice gauge, why does no one have a TSO'd model?

Since these gauges are knock offs of the original ones, I'm not sure how you can tell by the pics that they are the Wag-Aero gauges.

Rule on panel stuff: Items required by TCDS need to be 'certified'. All others, no. So if you replace one gauge with another, if both have been 'certified' (through one means or another) the replacement is legal. If you replace a gauge required by the TCDS with a 'non-certified' unit, you need to get a field approval.

In some cases, older aircraft were produced at the factory with gauges we wouldn't put on a lawn mower, now. Those gauges are still legal as they were okay'd by the faa (or CAA) under the original certification of the aircraft.

Web
 
Since these gauges are knock offs of the original ones, I'm not sure how you can tell by the pics that they are the Wag-Aero gauges.

Rule on panel stuff: Items required by TCDS need to be 'certified'. All others, no. So if you replace one gauge with another, if both have been 'certified' (through one means or another) the replacement is legal. If you replace a gauge required by the TCDS with a 'non-certified' unit, you need to get a field approval.

In some cases, older aircraft were produced at the factory with gauges we wouldn't put on a lawn mower, now. Those gauges are still legal as they were okay'd by the faa (or CAA) under the original certification of the aircraft.

Web

I was assuming the gauges must be the W.A. ones as I have not been able to find any other source for that horizontally split gauge. Was hoping that there was another source that offered a TSO'd or PMA gauge even at twice the price....
 
Since Univair does not seem to list their approved Piper pressure/temp gauge, formerly U450-680 I would say Bob Turner got the deal of the day with the free one from Eddie!
 
Try umainstruments.com they manufacture certified instruments and are great to work with. Their phone 800 842-5578
 
Yes, Eddie was good to me. I am trying to pay it forward double.

His gauge has worked flawlessly for 20 hours. My personal Cub has a US Gauge version (looks the same) and I put it in in 1963. It, too, works flawlessly. It has survived 54 annual inspections without a TSO.

I guess I would say the Wag gauge is not a bad deal, considering US Gauge would probably charge a grand each if they still made them. Most modern gauges are cheapie electrically powered stuff.

My Decathlon came from the factory with Stewart-Warner hot rod gauges.
 
Back
Top