How do you remove the top cylinders? Can the third hidden bolt on the back of the cylinder be removed without removing the entire top mechanism bracket that it is bolted to?

I have a leak somewhere on the top of the right one.

Here is how I removed them. Remove the inner bolts and loosen the outer bolts. Then pry the outer bolts as far as they will go and twist the hydraulic ram 90 degrees. It will pop out pretty easy. BTW look at my last post for rebuilding the ram. I replaced a 50 cent o-ring and stopped my leak. Sure beat paying $300 for new rams.

Thanks. That is good news. So far I have not been able to get enough clearance by prying. Maybe the body is fraction more inboard on mine but now that I know that works, I'll see if I can shave or indent the inner body in that spot a 1/16th or so and try again.

I'm not sure if it's the cylinder or tubing that is leaking until I can get the thing out but that o-ring sure sounds a lot better than getting a new pair. I priced them from several vendors and they are not cheap. I'll search for your other thread.

It may yet be the tubing. I see a couple partial cut-through abrasion points where they have rubbed against the sheet metal.

The only prying I did was to move the outer bolt as far outward as it would go. Rotating the ram cylinder was the real key. At first I was reluctant for fear of destroying the nylon bushings but they came out undamaged. Yours might be tighter than mine but both of mine came out pretty easy without any shaving or bending.

I'm super pumped to find this thread!
I thought I blew a line, but now I'm sure it's the cylinder (cause I can see fluid at the joint between the housing and the ram).
I went to NPD (cause I was in the area) and bought the line kit ($44) and the cylinder ($110) just in case, but if I can just rebuild the cylinder I can take it all back. I love this forum!! Did anyone find the other thread about the rebuild so I can be more lazy?
Then I wasn't sure how to get the cylinder out, but between this and Yellowbird's awesome body manuals, I should be ready to go!

hokie1984, Is this the thread?: Convertible Top Hydrolic Ram Success

Finally got the ram out. I did have to work the body over a hair at that point to make room for the bolt to clear. I suppose the factory body welding was a bit off.

I cycled the cylinder a couple times. Without resistant on it there wasn't much leakage but the ram had a slight coating on it when it came out of the cylinder so I will try the o-ring fix first. Was the O-ring a common one available at ACE Hardware or auto parts stores?

Not sure what was used originally, but when you get the old one in hand if that's the route you end up going, go to Napa or Carquest and match it up to the green teflon type orings that are used in newer A/C systems. You should never have to replace them again.

Thanks Jeff. I wasn't aware of teflon rings. That's what I'll look for.

hokie1984, I assume the o-rings will stretch sufficiently to get over the ram end and the washer(s)? Or do you have to open the cylinder somehow and start from the bottom?

Hi Jim,

Did you or are you taking one or both of the cylinders out? It's a real pain to get the tubes screwed on the rams if you have the ram bolted in already.

I have found that screwing the tubes on when the system is out of the car is the best way to insure you don't kink the lines.

I also used tie straps to hold the lines to the rams so that they do not rub against the outer body or get yanked when the top is going up or down. It worked well for me. Just my .02 cents. I've got the whole system out of the car and still connected.

Hope all is well. Now that the weather is getting better I am starting on my project again...It never ends. I've got the rear Driver quarter, tail panel off the car and the pass floor is getting some work also. Need to buy the sheet metal and continue.

Mark

I purchased my o-rings from a hydraulic supply company but they look like standard o-rings you can get from ACE. Yes the o-ring can be stretched over the end of the ram. After reassembling the rams, here is how I purged the system of all air. First I pulled the ram fully out on the bench. Then I attached the nipple that comes on the bottles of differential oil to the bottle of hydraulic oil. Then I put this nipple over the top hose connection on the ram and pushed the ram down. Next I attached the top hoses and bolted the rams in place. Then I took a large veternary syringe and pushed all the oil and air over to the other ram (I had this tube elevated). With all the air out I carefully attached the bottom hoses. When I got done there was no/minimal air in the system.

Thank you again hokie1984. I got the cylinders resealed and back in the car. After a couple full raise and lower cycles, I find no leaks. Before I put all the bracing, panels and seats back in I'm going to let it all sit a couple days and cycle them a couple more times just to be sure.

It took a while to find the optimum size o-rings. I tried three before getting two that seemed to fit tightly on the ram and in the grove it sits in. Hopefully the 5/8X7/16X3/32 I used will be continue to work.

A couple observations and hints.

- Getting the washers out of the indentation was difficult. I ended up grinding down a dental pick (a cheap Harbor Freight set) to a thin hook that I could work under the washer to lift it up.

- I got away with leaving the plumbing intact. The bleeding was easier being able to turn them upside down to bring air to lower connector.

- Don't drop one of the ram end nylon bushings down into the quarter or you have to open the window access panel and fish it out.

Hope your project is doing well Mark. And, good idea. I will use some ties and electrical tape to protect the plastic tubes this time. Although mine appear to have not cut through all the way yet, there is wear where they turn around the body sheet metal.

I had the same issue finding the appropriate o-rings. Turns out after 40+ years they tend to shrink a bit. I opted going for the slightly larger hoping they would squeeze down on the shaft a bit more. The one I rebuilt I had to take a lot of metal off because the snap ring scored the shaft a bit. If I can get it to seal with a previously scorn shaft, I am confident yours will work out fine. After over a month after rebuilding, still no signs of a leak.

What happened to the post on rebuilding the cylinder? I’ve searched and can’t find it

Thanks
Trey

Trey, I only recall three threads about fixing leaks in them:
- this one
- Contvertible Top Hydraulic Ram Sucess
- convertible top piston leak

bringing this oldie backup on top, I've read this thread and the quoted ones a few times, but not sure I understand the process to remove the cylinders. The OP mentions a third bolt, but I don't see it on the diagram. Also there's mentioned to an outer and inner bolt, which are these? Since pictures seem to have been purged, I'll update with a few to help illustrate my difficulties to remove the pump cylinder.

I removed bolt #1 and will remove #2 next. How can I avoid from dropping the nut on the other side when removing #2. Also opposite to bolt #1 is bolt #3. Not sure how it's possible as there is no room.

That is a picture of a manual top with spring assist. Here is an illustration from the gm parts book that shows both power and manual types. http://www.teufert.net/partbook/67-76/14-i.pdf As far as dropping the nuts with the top fully down there is plenty of room to slide a telescoping magnet down to catch them. or you could remove with the top up and they would be near the top of the opening but there is really no need.

The best way I can describe it is you need to rotate the ram to get the outer bolts out while the bolt is still in the bracket.

Was going to ask if it's easier done with the top up. Lemme see if I can get the top up as I lost quite a bit of fluid the last time. I'm putting in new carpet so better rebuild both while it's stripped