Andy95W

Just spit balling here, but if there was unconscious pressure on one brake pedal by a lazy foot, and then the parking brake was engaged, pressure would be trapped below the park brake valve. The master cylinders are connected with a Tee fitting, which could theoretically allow pressure to equalize between both master cylinders. And as Richard pointed out, it would take very little hydraulic pressure to lock a brake before rotation. At this point we're all just guessing, right? It sure would be nice to know the real answer.

Yes, I've seen your picture with the parking brake knob hiding behind the iPad. I had to label my knobs because I kept pulling on the wrong one...

The parking brake valve simply traps fluid and pressure. Once the parking brake is set, fluid and pressure below it are trapped and physically separated from the fluid reservoir above it. Is it possible that in flight you pulled on the parking brake knob instead of the heater knob? And when it didn't pull out as far as you were expecting, you pulled hard enough for the plunger with the 6227-1 o-ring to be jammed into the seat? My bet is that if you stick one arm into your pilot window and push on the knob at the same time you're pushing the plunger arm away from the valve it'll unstick itself and everything will be back to normal (except your tires, of course.)

I used the Airtex carpeting and I can say that for the money, it is probably the best bang for the buck in the industry. It fits perfect, is bound nicely, and for your M20F is only $289- including the baggage area. The only thing I don't exactly love is the style of the carpet itself. I'd prefer a closed-loop type, but I'm a CB so I love it.

Please do not adjust anything on your landing gear unless your A&P has the landing gear rigging tools. Paul Steen's former gorgeous M20C will never fly again for probably this exact reason. There is no "Up" adjustment on the Johnson Bar Mooneys. Only down. This gets checked every annual inspection with the gear rigging tools. By adjusting the rod ends to get more up travel, you will remove the pre-load on the overcenter link and the gear will collapse. It doesn't matter that the right gear doesn't touch the pad in the wheel well. There is a thread here recently about a broken rod end due to an electric gear Mooney that was pulling the gear up too far. Your A&P should put a good, critical eye on all of the pushrods to make sure none are bent. This will require removing the small panels in the gear wells that are inboard and forward to follow the pushrods from the wing into the belly. If all of the tubes are straight, and the downlock pre-load test is correct per Service Instruction M20-32/ Service Bulletin M20-155 (not the maintenance manual- that was for the original gear links) for both mains and the nose gear, then it's good and you should adjust the rigging of the gear door. (I'm not right about everything but I'm an A&P/IA that's owned 2 different M20Cs for about 17 years total.)

I just did mine last summer in Airtex seats. The main reason was that I was redoing my whole interior and wanted all the fabrics and colors to match. From a cost perspective, it's really not cheaper than having a local upholsterer do it. The up side is that you can do it at your own pace, which is particularly useful if you're doing your whole interior as I did. Additionally, you can do extra work on your seat frames while you have everything stripped. The workmanship of the Airtex products is exceptional. The downside is that what you get in the package is glued foam forms, sewn fabrics, a big flat panel for the rear seat back, and no instructions. This was my third aircraft interior, and I'm an A&P, and I still found a friend who had done car and airplane interiors to help. Some pieces were intuitive and some weren't.

+1. And it keeps raw fuel from running out of the carburetor air box.

I'm not going to give a definitive yes or no, but about 20 years ago I had a student that bought a brand-new A36 with GAMIs installed at the factory. It ran very well and very smooothly LOP. He/we put a lot of hours on it. Over time, it wouldn't run smoothly lean of peak anymore. Then, after his first annual, it was back to smooth LOP. After that he started having the fuel injectors cleaned every 50 hours and didn't have a problem.

I just removed "Repair Parking Brake Valve" from my to-do list.

This is my door, with fabric covered Kydex installed with 6-32 screws and rivnuts. I should probably take pictures of my complete interior using some Spatial Interior pieces, some original, and some fabricated.

For anyone interested, these are examples of the clips the OP was referring to. Again, they weren't used after the 1964 models.

I beat you to it, Chris. Bruce Jaeger's 3M Dual Lock:

Yes- but it may be more trouble than it's worth. I used to have a '67 M20C, with window trim that mounts similarly to your M20F. From what I remember of that interior installation, it was better to use the sheet metal screws. It would be worth taking the time to remove the frames and discuss it with someone who's installed rivnuts in the past, though.

Those clips are used for the pre-65 models. Since you bought the Airtex interior pieces, you'll be kind of stuck using them. They're really not that bad and hold very well without the gap that you would get from Velcro or the Dual-lock fasteners. I just redid my 1964 interior and got rid of all of those clips by using 6-32 rivnuts and fabricating my own panels. You could definitely do the same with the Airtex pieces, but it's a lot of work. https://www.aircraftspruce.com/catalog/hapages/rivetnuts.php

And I agree with Ross- he's very knowledgeable- the pump could have been reassembled incorrectly. That is a potential source for air to get into the system.

I was just going to go back and edit my post. The 20-25 extensions and retractions will slowly get the air out of the pump only after the rear hydraulic cylinder has been bled per the maintenance manual and there is no air in that cylinder forward to the pump unit. I hate to say it, but I would remove that rear cylinder and replace that o-ring again, make sure it's not rolled, re-install, and start the bleeding process again. Should only take about 30 minutes and an o-ring for less than $1.

Did your mechanic rebuild the pump unit, the slave cylinder at the flaps, or both? The extra pumping before movement sounds like air in the system. About 20-25 extensions/retractions, with a few minutes pause between each, will slowly get the air out- just as long as air isn't getting in, of course. The other issues such as not locking in position, no hydrolock on the pump, and not extending in flight sounds like the slave cylinder back by the flaps has a bad o-ring or a definite air leak somewhere in the system. Good luck. You'll find the culprit eventually and get it working right. Please keep us posted.

AirParts will overhaul them for a lot less. http://www.airpartsoflockhaven.com/air-parts-services

Probably Silicone Spray, then wipe with a clean rag or paper towel.

Last year my CO was usually around 4-5 in flight. This past summer, I installed a new interior, re-taped the floor, fabricated new rudder boots that actually fit tight, and redid the seals in the nose wheel well. My CO now reads 2 and doesn't seem to change. On the ground, it is less than 10. I didnt think the work would affect the CO until I read this thread and noticed the difference myself.

^ ^ ^ ^ One of the best, short descriptions of the charging system and ammeter I've seen.

You probably don't need the shims, but I would suggest installing them now, one at each mount point. This way, when the time comes in 500 hours to adjust it, it will be easier than having to add shims later. Also, this is per Don Maxwell's write up.

3) Leave everything as is, use the belly antenna for the hand held. 4) Remove the belly antenna and gain 10-20 knots of speed (and your mechanic will appreciate it every time he has to slide beneath your airplane).

And to add to the above- if you still can't find it, give them a call. The people there are knowledgeable enough to know what you need just from a year/model and a description of the part. (That's how I got the speaker cover for my 1964- it wasn't in the catalog.)

If it clogs with ice, you just need to warm it up. Consider using the extra long one, for safety: