Trouble replacing grease fittings - suggestions?

[Cave]

'31 Coupe


I ordered the modern style zerks from Snyder's along with the modern installation tool. Unscrewed the threaded ones and replaced with no problem, then pried out the old press-ins with a chisel (worked great) and I can't drive the new press-ins in more than about 1/4 of their shank... the grease gun blew two of them right back out.


I'm using a heavy ball-peen hammer with the installation tool (A-353020-M) and fram the fitting like I mean it... only one of the four ridges on the shank drive into the car part - which ever it may be. WHAT am I doing WRONG?

And the angled drive-in ones are still on my bench... don't have a clue how to drive them in.

[Joe K]

Originally Posted by Cave

'31 Coupe

I ordered the modern style zerks from Snyder's along with the modern installation tool. Unscrewed the threaded ones and replaced with no problem, then pried out the old press-ins with a chisel (worked great) and I can't drive the new press-ins in more than about 1/4 of their shank... the grease gun blew two of them right back out.

I'm using a heavy ball-peen hammer with the installation tool (A-353020-M) and fram the fitting like I mean it... only one of the four ridges on the shank drive into the car part - which ever it may be. WHAT am I doing WRONG?

And the angled drive-in ones are still on my bench... don't have a clue how to drive them in.

The advantage of the old style alemite fitting on the Model A is that the pressure of the gun helps hold them in place.

Think of the Model A grease gun - the one that was part of the tool kit. You push with your hand on the handle and the pump portion of the gun takes on this hand pressure and moves grease into the alemite fitting and bearing cavity. You also push down on the alemite fitting to make and hold the seal.

Thus, you pressurize the bearing cavity BUT for alemite system the pressure in the cavity cannot exceed the pressure of the gun on the top of the alemite fitting. Everything works although the arm and hand of the alemite operator is not QUITE so happy having to do the "opposite & equal" force on each and every fitting.

NOW replace an Alemite fitting with a Zerk fitting. You have possibly 10s of thousands of pounds of hydraulic pressure to move grease and pressurize the cavity and you need only a modest hand pressure to hold it in place because the grease gun "locks" onto the fitting. You pressurize the bearing cavity and the relatively unrestrained pressed in Zerk backs out of its press fit doing what hydraulic forces meant for it to do.

I have tried the Zerk fittings when I was into my "make it better - make it easier" stage of Model A evolution. Unfortunately I had EXACTLY the same problems as you're having now. And I imagine a whole lot of those who "did the conversion" are now wishing they did not.

It is possible to compensate for the tendency of Zerk fittings to back out: this done by HOLDING the Zerk gun in a press fit on its Zerk fitting. But that kind of defeats the purpose of a Zerk fitting? Besides possibly messing up the click-on clutch inside a Zerk nozzle?

I mean how badly do you want to have the advantage of a Zerk fitting? It is possible to tap and use a 1/8" pipe thread on EVERY lubrication point - no doubt there are Zerk fittings made that will accommodate and replicate every funny Model A type fitting - and they all screw into 1/8" pipe. Or some other thread?

Sorry for the bad news. I wish I kept all those Zerk conversion fittings for the Model A - so I could sell them half price to those who want to experience a Model A mistake at lesser total cost.

As it was they went in the trash.

Joe K

[emf]

Is it possible that when you used the hammer and chisel the old fitting was cut? Maybe there is a piece of the old fitting still in the hole... When I converted mine, I grabbed the old fitting with a pair of Vise Grips and twisted them out. Piece of cake! When the new zerk comes out with the grease pressure, inspect the hole to look for parts of the old fittings. While some in the know think it's a mistake to remove the old fittings, I found it quite an improvement.



Frank

[Cave]

Removed this way - tapped a chisel at 3 or 4 places around the circumference of the old fitting and then actually rolled them out by hand, not even pliers. I'm confident there are no remains in the holes. Keep the ideas coming, they're APPRECIATED. Thanks.

[duke36]

Just completed the job on some shackles with the drive in types. I normally use the threaded ones but not this time. Had the same issue and had some older new drive in zerks that fit better than the vendor's. With the latter, one can use a drill bit to ream the holes slightly by hand. I use some Permatex threadlocker before knocking them in with a bearing removal tool to suit. One can use a small socket as well as a driver.

[Jeff/Illinois]

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Interesting thread. I always thought that the modern type fittings had to be better now I'm re-thinking that.

I blew the end off the drag link on the '36 Ford a couple years ago with the modern fitting, now I know why I did that.

[Pete]

You can get fittings with either 1/8 pipe thread or 1/4-20 thread.

[redmodelt]

There should or you need to make a notch in the side of the driver to fit over the angled type. Would still work with the notch to drive in the straight type.
I do not recall having a modern drive in Zerk come out using a hand type grease gun. In fact a few i have installed are not seated all the way because they would not go in any further. If it is taking that much pressure to get the grease in the fittings than I would be looking for problems with fit of part, blocked passage or bad Zerks.

[larrys40]

I put them in all the time. Sometimes the fittings are tight. You will notice the ribs on them. On tightcfits I have taken them to my small belt sander and sanded down the rib portion so the OD is smaller. If you have a dial caliper measure hole and fitting. You need enough press in interference to make them tight.

I typically don’t have any issues doing it when needed after this fix.

Larry

[Garagekulture13]

Originally Posted by Joe K

The advantage of the old style alemite fitting on the Model A is that the pressure of the gun helps hold them in place.

Think of the Model A grease gun - the one that was part of the tool kit. You push with your hand on the handle and the pump portion of the gun takes on this hand pressure and moves grease into the alemite fitting and bearing cavity. You also push down on the alemite fitting to make and hold the seal.

Thus, you pressurize the bearing cavity BUT for alemite system the pressure in the cavity cannot exceed the pressure of the gun on the top of the alemite fitting. Everything works although the arm and hand of the alemite operator is not QUITE so happy having to do the "opposite & equal" force on each and every fitting.

NOW replace an Alemite fitting with a Zerk fitting. You have possibly 10s of thousands of pounds of hydraulic pressure to move grease and pressurize the cavity and you need only a modest hand pressure to hold it in place because the grease gun "locks" onto the fitting. You pressurize the bearing cavity and the relatively unrestrained pressed in Zerk backs out of its press fit doing what hydraulic forces meant for it to do.

I have tried the Zerk fittings when I was into my "make it better - make it easier" stage of Model A evolution. Unfortunately I had EXACTLY the same problems as you're having now. And I imagine a whole lot of those who "did the conversion" are now wishing they did not.

It is possible to compensate for the tendency of Zerk fittings to back out: this done by HOLDING the Zerk gun in a press fit on its Zerk fitting. But that kind of defeats the purpose of a Zerk fitting? Besides possibly messing up the click-on clutch inside a Zerk nozzle?

I mean how badly do you want to have the advantage of a Zerk fitting? It is possible to tap and use a 1/8" pipe thread on EVERY lubrication point - no doubt there are Zerk fittings made that will accommodate and replicate every funny Model A type fitting - and they all screw into 1/8" pipe. Or some other thread?

Sorry for the bad news. I wish I kept all those Zerk conversion fittings for the Model A - so I could sell them half price to those who want to experience a Model A mistake at lesser total cost.

As it was they went in the trash.

Joe K

I've been considering converting over to all zerk fittings also so this thread got my attention. After reading Joe's response it settles it for me and stock it'll be.

Sent from my SM-N950U using Tapatalk

[ahirt]

I replaced some grease fittings. Had same problem. Put them in the freezer overnight and they drove right in. If they still don't go in, buy some dry ice. Getting that cold will shrink them enough to go in for sure.