Lubrication and Other Fluids

[noema]

I have finally started my build and I am loving it so far. It's a lot to take in at first but it's also very addiction to solve all the small mysteries and riddles.

I started with the tank cap and the main landing gear. It turned out I am missing all kinds of fluids. This is the list I came up with but would be interested what other builders are using.

• MIL-H-5606 ATF to fill shock struts and lube o-rings
• MIL-H-5606 brake system (later)
• Loctite 243 565 to seal threads
  • shock struts (don't like handling leaky parts)
  • NPT threads in fuel system (with Loctite 7649 primer)
• Loctite 620 retaining compound (tailwheel rod/socket, in case of play)
• EZ Turn to lubricate tank cap threads
• Aeroshell-22 to pack Grove wheel bearings
• Aeroshell-22 to lube o-rings in tank cap and other general lubrication needs

I am also wondering what lubes people generally use. For example I would like to stick with one general purpose grease (e.g. Aeroshell-22) but I noticed that Aurora (for rod ends) doesn't list it as recommended grease. My main concern is mixing incompatible lubes. There are lots of stories about the two mixed greases liquifying and significantly decreasing the lubrication intervals, for example.

[Mark Goldberg]

Hello Stefan. I will send you an email. Mark

[Bcone1381]

You'll need a tapered thread sealant. Seems like Loctite 567 or Permatex #2 is often used. I have both.... Permatex was on hand but they did not recommend it for the fuel sight gages clear PVC tubing (plastic) but Loctite is proven successful there. So you might consider Loctite 567 superior.

....and Torque Seal to indicate a nut was torqued to specifications.

disclaimer. I have not yet tested any of my joints for leaks in real life. Lets see if others chime in and see what they use.

[Nev]

Is there any issue with using a normal automotive transmission fluid in the shock struts, and an automotive wheel bearing grease for the wheel bearings ?

For the Brakes, Grove specify Mil-H-5606 red hydraulic fluid Here

BTW An excellent website you have put together there Stefan.

[Mark Goldberg]

ATF is what you want to use in the shock struts Nev. And if Grove does not give any guidance for which grease to use on their bearings - I do not see why a good quality auto grease would not be OK. Probably a good question for one of your AME friends. Mark

[noema]

I guess I took some recommendation from the forum about MIL-H-5606 without checking it much. Are ATFs all the same? What kind are you using? I don't like it's not spec'd. Is this mostly about viscosity, ATF having higher viscosity?

FYI, Grove does recommend Aeroshell-22 and has the bearings lightly greased with it when shipped.

Thx Nev, website is just getting started I like yours too. It has been very helpful.

[svyolo]

I was about to ask about sealant for the PVC sight gauges. Loctitte 567? I already have it.

[Bcone1381]

I may have been presumptuous by mentioning the 567 product. "Loctite Thread Sealant" without any specifics is specified in the Beartracks article. I'm cautious..... Loctite thread LOCKER (not sealant) around Lexan resulted in cracks. I spent way too much time down the "fuel sight gage sealant rabbit hole". It would benefit out community if we had a specification.

[jaredyates]

Brooks, which article is that? I'll get some clarification.

[Nev]

I was about to ask about sealant for the PVC sight gauges. Loctitte 567? I already have it.

I’m curious if anyone has Not sealed their sight gauges…….and if so, how that worked.

[N942VT]

Why would you not Nev? Maybe because it looks terrible through the PVC? If so shrink a 1 inch piece of black shrink tube to cover the threads.

[Nev]

Why would you not Nev? Maybe because it looks terrible through the PVC? If so shrink a 1 inch piece of black shrink tube to cover the threads.

The type of AN fitting that I’ve used doesn’t have threads, rather a small flange that inserts into the clear tubing.

[jaredyates]

The type of AN fitting that I’ve used doesn’t have threads, rather a small flange that inserts into the clear tubing.

If you are using a barb fitting into soft tubing, don't use sealant. If you are cutting NPT threads into hard clear PVC, absolutely use sealant.

[noema]

Just a side note. There is this Loctite guide (pdf). All their different thread lockers and sealants did not make sense to me before I read this. For example 567 is a less strong version of 565.

image_9417.jpg

[svyolo]

Near the bottom of my tube of 567 it says "NOT FOR USE ON PLASTIC PIPING". I wonder about just using PVC glue?

[svyolo]

I did find a brand called Rectorseal that has a couple thread sealants compatible with PVC and gasoline.

[Bcone1381]

Very Good! I did not see that. We'll see what happens...if I have issues I will report back.

[zkelley2]

There's a bunch of types of ATF. Generally it's viscosity changes a lot in the cold. 5606 is good down to -60F.

[podo]

Although Grove recommends MIL-H-5606 here: https://www.groveaircraft.com/brakeinstall.html
they refer to a replacement in MIL-PRF-87257 here: https://www.groveaircraft.com/fluid.html

[svyolo]

I did a little more looking and ordered Rectorseal #5 off Amazon. 1.75 oz tube was less than 4 bucks. Recommended for PVC, gasoline, and gas/ethanol.