Grease fittings question

[BaldEagle]

I tried searching this site but couldn't find anything.  I cannot get grease through these two Zerk fittings on either main gear.  I replaced the Zerk fittings and a 120 PSI of grease with my pneumatic grease gun won't push grease through.  At this point, are there any options other than pulling out the bolts and cleaning everything up? (I'd ask my A&P / IA but he's out of town).

[Guest]

I’ve seen this a few times we’re the bushing is virtually seized and won’t take grease.  I made a steel drive pin on my lathe, it and a piece of steel tubing on the opposite side with a large C clamp to press the bushing out.

I polish the bushing in the lathe and run a reamer through the gear leg and reassemble it.

Clarence

[Warren]

Every year this is a fight for me.  Usually jacking the aircraft and taking the weight off will allow grease to flow in without too much pressure.

[RobertGary1]

Do you have the weight off the gear?

 

-Robert 

[smwash02]

I had the same problem this year on all 4.

Loosen the bolts a bit and try again.

[PT20J]

As others said, jacking and getting the weight off it often works. Also, I found that the front MLG bearing that attaches to the spar takes grease better if you retract the gear slightly so you can wiggle it while greasing.

Skip

[GeeBee]

That is it. Get the weight off the gear. I even used a "Zerk Zapper" with an air hammer attached and could not even get Marvel Mystery Oil through them. Then during annual while it was on jacks, I walked up and with hand grease gun and pushed grease through like soft butter. 

 

 

 

[BaldEagle]

Partial success after putting it back on jacks.  I was able to get grease through 3 of the 4 fittings.

[GeeBee]

First replace the zero, they're cheap. If that does not work, try a Zerk Zapper with weight off the wheels using Marvel Mystery Oil.

 

[1980Mooney]

On 11/1/2020 at 4:04 PM, BaldEagle said:

Partial success after putting it back on jacks.  I was able to get grease through 3 of the 4 fittings.

Did you partially retract the gear while up on jacks?  Just jacking up and releasing the vertical force does not always unload the joint especially if the clearances are really tight on that particular joint.  I like to unload the overcenter springs and be able to wiggle the gear a bit if it is not taking grease.

[larrynimmo]

FYI...I am going through annual now and I have 3 Zeek’s not taking grease....even with my mains in partial, and wiggling I am not getting any grease at the front main gear swing bearing...I have ordered a “Zerk buster” off of eBay and I will give it a try...thankfully none of these three bearing areas show any wear or play what so ever.

[PT20J]

7 minutes ago, larrynimmo said:

FYI...I am going through annual now and I have 3 Zeek’s not taking grease....even with my mains in partial, and wiggling I am not getting any grease at the front main gear swing bearing...I have ordered a “Zerk buster” off of eBay and I will give it a try...thankfully none of these three bearing areas show any wear or play what so ever.

Be a little careful with the front MLG bearings as they use press-in zerks rather than pipe threaded zerks. @M20Doc might have some thoughts on these. 

[MikeOH]

1 hour ago, larrynimmo said:

FYI...I am going through annual now and I have 3 Zeek’s not taking grease....even with my mains in partial, and wiggling I am not getting any grease at the front main gear swing bearing...I have ordered a “Zerk buster” off of eBay and I will give it a try...thankfully none of these three bearing areas show any wear or play what so ever.

Discounting pressed in Zerks, why not just replace the Zerk versus trying to clear it with a "Zerk buster?". They can't be that expensive, can they???

[larrynimmo]

3 hours ago, MikeOH said:

Discounting pressed in Zerks, why not just replace the Zerk versus trying to clear it with a "Zerk buster?". They can't be that expensive, can they???

These pressed in zerks have no ball and I can press locking wire well through the oriface....

but still won’t take grease

[GeeBee]

They are not, but the blockage is not always at the zerk (which you should look at first). Old grease at the bearing surface often blocks new grease entry.

 

[1980Mooney]

17 hours ago, PT20J said:

Be a little careful with the front MLG bearings as they use press-in zerks rather than pipe threaded zerks. @M20Doc might have some thoughts on these. 

Also be careful on the rear MLG bracket/bearing if you have a J with serial number 763 and below.  The early models also used a drive-in/press-in #3019 zerk fitting there.  Newer models were screw-in.  You can put enough pressure to blow them out.  At that point you will be stuck having to use a grease gun needle with rubber tip.

[larrynimmo]

My issue is with the front MLG....and my serial is 1189, and they are pressed in...I will tread carefully on experimentation and I will report back on success or failure.

[PT20J]

According to my M20J IPC, the MLG front trunnion bearing uses an Alemite 3019 1/8" straight steel drive grease fitting without check ball.

Effectivity lists 24-0001 thru 24-1487, 24-1489 thru 24-2999, 24-3079 thru 24-TBA.

Skip

[Bolter]

For the Zerk impaired...what is Zerk Zapper and Zerk Buster?

Is either of those this grease coupler attachment (that I already have)?  

https://smile.amazon.com/LockNLube-fittings-best-selling-Long-lasting-rebuildable/dp/B00H7LPKKU/ref=sr_1_7?dchild=1&keywords=zerk+zapper&sr=8-7

[RobertGary1]

On 11/4/2020 at 10:08 PM, Bolter said:

For the Zerk impaired...what is Zerk Zapper and Zerk Buster?

Is either of those this grease coupler attachment (that I already have)?  

https://smile.amazon.com/LockNLube-fittings-best-selling-Long-lasting-rebuildable/dp/B00H7LPKKU/ref=sr_1_7?dchild=1&keywords=zerk+zapper&sr=8-7

The tool you note is about the most amazing thing invented for saving hours pushing grease but for clearing out a goobered up fitting something like this.  
Innovative Products Of America 7862 Grease Joint Rejuvenator https://www.amazon.com/dp/B000JFL7TY/ref=cm_sw_r_cp_api_fabc_P2dQFbS9G59R3

 

[GeeBee]

https://www.zerkzapper.com

 

 

[Tom Johansen]

Hi, I too have had difficulty with stubborn grease fittings on a M20C. Pneumatic grease gun really helped. A really great source of fittings is https://www.huyett.com/

It's always good to see nicely painted LG. Kudos

[67 m20F chump]

I have had good luck with Lock N Lube.  It doesn’t cost much and saves some time.

[larrynimmo]

Update....on the front MLG I used the grease buster device and when I hammered you could see liquid come out at the shaft...and while I did put some grease in, did not get the full transfer I was hoping for..

when I went to remove the grease fitting from the MLG zerk, the pressed in zerk actually pulled out...the bearing base appears to be a brass body, and I was able to tap the zerk back in...it stayed in...from now on I will be using the release lever type of grease fitting when I grease or bust these more delicate zerks

[PT20J]

On 11/16/2020 at 3:59 PM, larrynimmo said:

when I went to remove the grease fitting from the MLG zerk, the pressed in zerk actually pulled out...the bearing base appears to be a brass body, and I was able to tap the zerk back in...it stayed in...from now on I will be using the release lever type of grease fitting when I grease or bust these more delicate zerks