Last year, I did a post on Care of Your Older Sewing Machine, where I took apart several machines and went through how to clean and oil them yourself to save money. Older machines, out of warranty, are easy to clean and this usually solves most stitch problems too. A small stray thread can create all kinds of problems! Unplug the machine before you start.
One thing that stymied me last year was getting the cover off my Pfaff 7550, which was running rough and skipping stitches. I knew there had to be some trick to it, but I didn’t know what that was. Thanks to Karen, a fellow Pfaff owner who recently came across the other article and emailed me, I now figured out all the steps to getting the covers off. Karen said ‘after you flip up the lid and remove it…”, ah what? That was the part I was stymied by! The screws were obvious, but the cover wouldn’t budge with the flip lid in place.
The clips seem to indicate that you move the flip lid towards the front of the machine but that didn’t work. I didn’t want to break the lid, so I left it.
No amount of searching told me how to remove that flip lid. But if Karen went by it that fast, it must be something reasonably easy. So I went back to it again, with a little more daring. I looked again, tried this and it worked. Push the clip towards the left with your thumb, and the little pin will disengage.
Then lift the lid off.
Move the bobbin winder to the right.
Remove the two screws. Do not remove the screw holding the bobbin check in place, it isn’t necessary and is a pain to get back in the right place.
Raise the handle.
Lift off the under cover.
Here are my tools for servicing a sewing machine. Several screwdrivers, three flat and one Phillips head, a tiny bottle brush, a nylon stiff bristle brush, several kinds of tweezers, canned air, sewing machine oil. and (not pictured) blue gear grease. New needles are good too.
Now, remove the needle and the presser foot. Raise the presser bar.
Take out the bobbin case. This will allow us to move the gears without damaging the bobbin case or the presser bar. Blow out the bobbin case with air, remove any stray threads, and put a drop of oil on the mechanism where the parts slide over each other, keeping it out of the area where the bobbin sits. Remove the throat plate to get to this area easier. Clean out the area around the feed dogs.
Back up top, look around for any obvious threads, and there was a big one here.
It was wrapped around one of the moving mechanisms, and deep in the workings. I used a hemostat to clamp onto the thread and gently pull while moving the hand crank to loosen it and pull it out.
The thread must have been there for some time, it broke twice while trying to remove it. I was able to pull some out, but there was a big loop left. Eventually, I did get all of it. Look for more fuzz and crud on the other moving parts and clean them.
Now look for gears and moving parts by rocking the hand crank back and forth. They need to be cleaned off, and regreased or oiled. All those spots where there are parts moving against each other need lubrication. The hole between the orange circles is a receptor for the screw, it doesn’t allow oil to get to the piston. It won’t hurt anything if you put some oil in there, it just won’t do anything.
Clean off the rods, oil the parts that move. There will likely be gunk in lots of places, so use a tiny bottle brush, and a nylon brush to get out the crud. Moving the hand crank will show you this piston moving along its bar.
One caveat, do not get any oil on the belt from the motor to the first gear. That will cause the belt to slip and your machine will run but not make stitches. If you think you got oil on it, turn the hand crank while you thread a paper towel under the belt to soak up any oil. Look around for any other gears or moving parts, remembering to stay away from the motor belt.
Also, keep the oil off the electronic boards.
Using a six pointed metric allen wrench, take out the side cover screw. Be careful to use the right tool, it isn’t a Phillips head and you can strip the points if you aren’t careful. Be aware it is metric and not US sizing. Just another way that Pfaff wants to keep you out of the machine. I removed it, but actually all you need to do is loosen it for the plate to slide off.
I borrowed this set up from DH’s garage.
If you have removed this screw with a Phillips, and you don’t have metric allen wrenches, replace the screw with a Phillips head for the next time you need to remove it. Take the side cover off.
Clean the schmutz out here too, and then lubricate the gears and pistons in this area as well.
Now, look at the batteries. Just lay the machine on its back, and take the battery cover off.
Oh, heavens! Maybe this is why the screen keeps changing back to German.
Change the batteries if they are corroded. Replace the cover and set the machine back up.
When you think you have all of it oiled, plug in the machine and turn it on. Step lightly on the foot control to listen to it work. If it sounds smooth, increase the speed. If you hear a clunking noise, or a squealing, there is something you missed with the oil or grease. Go back to the hand crank and follow all the moving parts to figure out where the noise is coming from. Inspect it carefully and remove any gunk, then oil. Then go back to the foot control, and increase the speed until you are pedal to the floor and the machine is running at its highest speed. Don’t worry, this won’t hurt it, but it will be sure that all the oil is distributed. If all sounds good, wipe off any excess oil inside and out so it won’t collect dust and become gunk in the future. Then, turn the machine off, replace the covers, place a paper towel under the presser bar, and let it sit for a day to allow any excess oil to drain out.
Replace the presser foot, insert a new needle, put the bobbin back in and you are ready to go. When you are done, thread it with different colors of thread in the top and bobbin and check your stitches. You can adjust the tensions to create perfect stitches if you know which one is the problem.
So, don’t be afraid to open up that out-of-warranty Pfaff machine and take a look. That noise you hear, or the rough running is might be a bit of crud on a gear or a rod, a stray thread, or something else that you can easily take care of yourself.