Need advice on Convertible top operation (and fix)

[70vert]

My convertible top stopped going "up" last fall and I'm finally getting a chance to dive into it, and don't know much about how to diagnose & fix ): 
* When I flip the toggle to lift/close it I can hear the motor whirring but nothing happens.
* I don't see any visible fluid leaks but assume the 1st step is the check if it is low - how do I do that and if it is low how do I fill it?
* If its not low on fluid does that mean the motor is broke (even though it sounds like it is operating) and I'll need to restore or replace?
* What other tips & tricks do you have for me to get this fixed? I'd like to do it myself, to learn and save some $$

Thanks tons for any help!

[anlauto]

Can you see the fluid in the lines ? is there lots of air bubbles ?

I would say lube up all the joints in the top and try and assist it by hand while someone else operates the switch.

[70vert]

thanks Alan that is exactly what I did, man that sucker is heavy!!  That was last fall/winter and I just left it up since it was cold. Now I need it to work (:

I will check the tubes tomorrow, kinda hoping I see bubbles or air-gaps and just need to top it off. Maybe they need to be bled, like brakes? I hadn't noticed any wet spots but didn't look real closely yet.

[1 Wild R/T]

Fluid is probably low...  There is a plug on the passenger side end of the pump, below it is the bolt that secures the reservoir to the pump... Remove the plug. use an oil squirt can filled with type F ATF to fill the reservoir till fluid is at the level of the plug.... Put the plug in, try running the top... After a little running of the pump stop, wait a minute, pull the plug & fit the reservoir again.... Repeat 3-4 times... By now the top should be working... Give it a few days running the top & you'll find your leak...

BTW the system self bleeds...

[anlauto]

  to be on the safe side, I would pull the back seat and interior panels...if there's a leak it would be pretty obvious. Thankfully you can get new pumps/hoses and cylinders even, pretty reasonably priced at https://www.hydroe.com/ 

[70vert]

Thanks guys, I'll give that a check tomorrow. And keep an eye on it for slow leaks. Will save the link too just in case.

[70vert]

Update: the motor/pump was very low on fluid so filled it per comments. It now easily goes down but struggles to go back up, really whines loudly. There is one hose connection that is leaking a tiny bit, not sure that would totally account for the issue but I will need a new one anyway so ordering at the HydroE site, and since they only sell both hoses I guess I'll replace both while in there. Next step would be to replace the motor/pump but don't want to spend the $$ unless needed, so that will draw out the process.

Thanks again guys for the feedback, it was definitely helpful!

[anlauto]

If the pump is whining away, it's probably on it's last leg...If a new one is not in the cards, they can be rebuilt fairly easy apparently. Seem logical to do it and the hoses at the same time

[Jay Bee]

Burdar did a motor/pump rebuild that's posted on FABO with pictures. I can't post a link from this device though, if nobody else does I will sometime tomorrow.

[1 Wild R/T]

Pump whines because there's still air in the system... And the top probably goes up slowly because.... There's still air in the system...

[anlauto]

After filling it do you still see air in the lines ? The lines should be a solid colour, red if you're using transmission fluid...you shouldn't see bubbles at all I agree if the system is full and properly bleed the pump shouldn't whine, unless it fubarred...

[anlauto]

...also the pump could be straining if the seals inside the cylinders are allowing fluid to pass by and the motor is working twice as hard as it should...   Could be issues with the cylinders you can't see

[1 Wild R/T]

...also the pump could be straining if the seals inside the cylinders are allowing fluid to pass by and the motor is working twice as hard as it should...   Could be issues with the cylinders you can't see

Yup, cylinders have been known to bypass internally...

[Jay Bee]

Here's Burdar's motor/pump write-up w/pictures.

https://www.forabodiesonly.com/mopar/ams/convertible-top-pump-disassembly.157/

[rjhjr]

I've a couple convertibles, one of which i got in 82.  IMO they always whine a little. When the seals start to go or get air in them they go wonky and whine differently.  If one cylinder is leaking internally it will go up crooked.  Pump rebuilding is rather easy, just don't loose the little balls for the ball valves. 

I've two under pressure for six months; no air at all, new lines, rebuilt motors, new cylinders on a rack and operate them periodically.  No air makes a difference as it compresses more than fluid.

I got my motor kit from here https://store.convertibleparts.com/pmprestkit.html but Classic Industries seems to be selling them.

I found used pins and bushings but it looks like these guys now make them - no idea if they are any good. https://www.convertibletopguys.com/convertible/329/1970-71-Dodge-Challenger#hydraulics


I've found http://topsdown.com
to be the best price for pumps, cylinders and hoses.  He also makes new track strips that are a perfect match.