Right landing gear oleo oil leaking

With the oil near the rear, I would also check the brake caliper for any leakage. It is much easier to correct than the main strut.

Bob Ripley
ABS Technical Advisor

That sure is VERY black for MIL-5606.

I’m with Tracy, that does not look like even very dirty 5606. I have had good luck with jacking the airplane and flushing the struts occasionally with a mixture of 5606 and Granville Strut Seal. Bleed it in and out by taking the valve core out, putting a clear vinyl hose over the valve stem and into a jar of clean 5606 and Strut Seal. Pump the strut until clean fluid and no bubbles comes out. I also use this mixture to bleed my brakes. My airplane has over 7500 hours on it and lives outside, so it needs all the help it can get!

I'd tend to agree with Bob. The lower strut casting and exposed piston would likely have an accumulation if it was the strut. If you blow the photo up, the bottom of the slave cylinder has a reflection on it, likely due to it being wet. Brake 5606, weeping past the seals, will wash out brake dust (a natural by-product of using your brakes), and look like that.

If it is the strut, a proper resealing and servicing is much better than 'swelling the seals'. The fluid can darken like that through age, moisture, and other debris being introduced to the fluid. Keep in mind the bottom 5" of the strut housing is not supposed to have 5606 in it; the felt pad contains engine oil for lubrication / proper operation of the strut.

Mike
ABS Tech Advisor

Metallic or organic brake linings?

Looks like a 6" wheel; that would be organic.

the image suggest that you may not have enough air in your strut. If I recall, the manual recommends about 4 1/2 inches of the strut to be seen.

I would put the plane on jacks so the strut is not compressed and then put connect an air compressor to it and inflate to 120 pounds. I would wait a day and then put a gauge on the strut to see how much pressure remains.

If there is still 120 pounds, then I would lower the plane and see how if there is about 4 1/2 inches showing. IF not, I would send both my mains strut to Delta Strut for overhaul.

Most professionals prefer Nitrogen, but the Model 35 manual section 5 page 8a only says 100 PSI.

When you get the struts back from Delta, they look brand new!

But, before I would do this, I would put my Bonanza on jacks, remove the wheels and brakes and examine the brakes. That material looks too black to be from the struts.

Tom

Wow, thank you all for the help! Here is a rear view of my A36. The leak is more visible from the rear. Does it changes anything to your evaluation of the culprit?

Thanks! Frank

In the new photo, it does look more like a strut leak than the brake caliper. I do not think the strut has been serviced with fluid in quite a while based on the color of the leakage.
My suggestion is to remove the strut, clean the strut and replace all of the seals and service with fresh MIL5606 and Nitrogen.
I agree with Mike that fresh fluid WITHOUT Granville Strut Seal is the best option.

Bob Ripley
ABS Technical Advisor

Thank you Bob! My mechanic asks if there are landing gear service kits available to buy or will he need to buy each seals separately? He is used to service Pilatus PC-12 landing gears and the landing gear service kits cost way less than ordering each separate parts individually.

Also, I have the service manual and the ABS landing gear inspection checklist and repair guide. It would save him some research time if you could point me to recommended repair instructions.

Thank you! Francois