DIY Convertible Top Cylinder Replacement (and rear seat removal details)

Discussion in 'SN95 4.6L Mustang Tech' started by Oh3yeller, Aug 23, 2011.

  1. Hopefully this will get stickied. I looked everywhere for instructions or pics on this subject and found bits of scattered info but no real pics or definitive "how to's". So here's my contribution. Hopefully more to come later.

    One of my top cylinders started leaking pretty badly. Both of them had puddles of fluid under them when I removed the seat. I was hoping it was just leaking lines, but the lines are perfectly good. Mine were both leaking around the O-rings where the lines thread into the cylinders. The stock cylinders are notorious for failure, and Ford has recently discontinued the OEM cylinder. There are 2 replacement cylinders being made (to my knowledge). One is sold (and perhaps made by) Convertible Service out of California. These are not crimped together at the top, but made as a solid unit. Probably the best design, but they were on backorder for at least a month or so and I wasn't willing to wait. The other replacement unit is sold by Blue Oval Industries. No idea who actually makes them, but the top of the cylinder is crimped to the pivot head similar to the stock units. They have a 5 year warranty when used with Dexron III, so I'm good with that.

    You will know your stuff is leaking if you hear the motor running at normal rpms when you hit the button, and it starts making funky whining noises and either doesn't want to go all the way up or takes forever. There is air in the system. If there's air in there, there is a leak somewhere.

    First, you need to remove the rear seat. This is done by locating the tabs under the seat bottom and pushing in the clips one side at a time to release the seat bottom. I've shown it with the seat removed for simplicity. You can't really see the clips with the seat in place.


    Once you have the seat bottom out, you'll loosen the two nuts on either end of the seat back. On the 2003 models, there is a LATCH bracket there for attaching a child seat. It stands to reason that this bracket could be placed in any SN95 if you found one at a wrecking yard or whatever.


    Pull slightly forward and then slide the seatback upwards to free it. It's actually harder to put back in than to remove. Watch the seatbelt guides that come over the top of the seatback. They are plastic after all..

    Now, you need to remove the rear interior trip panels on both sides. There are four plastic retainer plugs that hold it in. Locations are denoted by white dots in the picture. You will also need to remove the front seatbelt anchor bolts with a torx socket so that you can slide them through the hole in the plastic panel. You need a set of torx sockets anyway, so go buy a set.


    Next, we'll remove the speaker assemblies on both sides of the car. Each one is held in by two torx screws (I told you you need a set). Unplug the speaker connectors first, then remove the two screws.

    Once you have the speaker assemblies off, you can see and access the lift cylinders. You will likely see puddles of transmission fluid on your floor there. Soak that stuff up. Kittly litter and a shop vac actually work wonders. You may want to wait till your done with the job to do the 100% cleanup though, b/c there will be spillage.

    Notice you have 2 lines coming into that cylinder. They are reverse flare fittings with orings in there. If you just have a little leakage, and there is nothing squirting out the top of your cylinder when you actuate the top - you may be able to just replace the little orings there where your fittings go in. This would be ideal, but was not the case for me. Mine was a squirter.

    The cylinders only have two fasteners. You can easily reach the pivot bolt. The second fastener holds the eyelet to the convertible frame lever. You will need the top in the 'up' position to be able to get at the eyelet fastener. It also has a bushing you will need to reuse in your new cylinder. Oh, and of course it's a torx bolt too.

    Location of the eyelet. This was tough to get a picture of, but you will see it if you're in there.

    You can unscrew your lines from the cylinders at any point. You need either paper towels or some cloth towels you don't care about. They are going to drip for a bit. Be careful with your fittings and your lines. I believe they're teflon lines with brass fittings crimped on. Also, take note or label which line is the upper and which is the lower. The hydraulic pump pushes and pulls at the same time. This design is part of the reason the cylinders give out... but I digress...Just make sure you put the upper and lowers back properly on the new cylinders or you'll be screwed.

    You will need to refill your top motor with fluid. You need dexron III or better. Automatic transmission fluid. To do this, you will pull the plug located on the right hand side in the picture.

    You will not put this plug back in until we're done. It's as PITA to get back in. The best way I found to do it is by cutting the sharp point off a wooden golf tee and pushing that inside the hollow hole of the rubber stopper and then using needle nose pliers to work the stopper back into the hole little by little .The idea is to stretch the rubber stopper so that it narrows enough to fit. Works decently. There's probably a fancy tool made for this application somewhere. Anyway, it's pretty easy to pull out. Just don't rip it. No idea where to buy a new one of those.

    Your new top cylinders will come fully retracted and the will have fluid in them. They will also have plastic caps screwed into the holes where your lines will attach. Resist the urge to play with them. You want the shafts in the same position on both cylinders so they're easier to install and bleed.

    Before you put the cylinders in the car, you'll wanna bleed the system. Hook up your lines to the new cylinders the same way they came off the old ones. I was told to tighten the fittings 1/2 turn past finger tight. Be sure you don't cross thread them. The cylinders are aluminum and that can be easy to do. I must admit, I tightened mine a little tighter than that. Basically, once you get to the point where you have to hold the square part of the fitting with piers while turning the other part with a wrench, just go half a turn. I think that's what he meant. It presses into an oring inside that keeps it from leaking.

    Once you have both cylinders attached to the lines, you'll fill your reservoir with transmission fluid. Again, paper towels are a good idea. Some will spill. I used a turkey flavor injector if scored at Big Lots for about 3 bucks.It's like a huge syringe. The hole is rather small, so you'll need some trick to getting it in there. You will need most of a quart of transmission fluid. Once you've filled it to the bottom of the hole, run your motor a few times with the button. You will need to top off the reservoir a couple of times. At this point you don't have the cylinders installed. I would suggest not going too far out with them because hydraulics are pretty strong, and you don't want to ruin your new cylinders or shoot your shafts out anywhere. I tend to err on the side of caution. Work them back and forth 3 or 4 times and the whining noises should dissipate mostly.

    Extend the shafts and bolt in your eyelets. Be sure you reuse your old nylon bushings or replace them. Those pop out with a screwdriver.

    Once you have everything lined up and bolted in, you can run your top up and down a few times. The air should be gone after a few more times and it will run smoothly. Make sure your reservoir of trans fluid is filled to just below the hole. Put your plug back in with the old golf tee trick mentioned above. It will take some patience and working it around in a circular pattern.

    Button everything back up and have another beer!

    Attached Files:

    jmee and Kilgore Trout like this.
  2. This is great. I have a 2000 convertible that is having issues raising the top. This will definately get me started in the right direction.
  3. It is almost two years later, and I recently came across this post. This process worked GREAT on my 03 Mustang. Thank you so much for the helpful photos. This posting gave me the confidence to "Do It Yourself". Everything worked out well.
  4. Great thread.
  5. nice... i probably would have opted for some units from the junkyard, but this works....i also had trouble with the plug in the top motor... i used an old, not so sharp screw driver and some elbow grease.... it's a tough plug..
  6. Just used this post yesterday. I was able to replace everything myself and now my top convertible is ready for the fall! Thank you for this post!
  7. these are great instructions and pics,... i refilled my green 01 top motor a few months ago .. my daughter was driving it then..i recently "inherited" it from her ( she got a nicer 02).. and found puddles under the car... traced them back and realized both my cylinders were leaking out the i'm probably going to clean it up, remove the cylinders temporarily and look for a good deal on some used cylinders that don't leak.. that is, if i can't salvage the old ones.. i think i'm going to remove them first and inspect to see if there is some way to fix them... fall is here, so top can stay up for a while.. i''ll give everybody an update when i get it all fixed...
  8. Took me no more than 10 seconds to install the rubber plug. I gripped the end of the rubber plug with vicegrips (just enough to have a firm grip on it). I then saturated it with automatic transmission fluid then installed it by pushing in and twisting. It was literally that easy.
  10. It took me no more than 10 seconds to install the rubber plug. I gripped the end of it with vicegrips then saturated it with automatic transmission fluid then pushed it in the hole while twisting it. It was literally that easy...I sprayed some silicone on the motors' rubber legs. I then took a flat screw driver and pryed the motor out of the metal bracket that it sits in. I was then able to tilt the motor up, I then took a small funnel and put it in the hole then slowly filled it up. I would only pour for a short time then set the motors' rubber legs on the bracket holes to see how full it was. Once the fluid came out, not very much I might add, I then sprayed more silicone on the rubber legs and pushed them back into the bracket holes.
  11. I'm glad this was helpful for some people. I haven't been on here in long time. Cheers!
  12. You were a huge help to me. Thanks