challenger convertible top slow going up, fine going down.

[Finoke]

Hi Guys,
I picked up a nice driver 70 Challenger convertible about a month ago. I am working my way through some minor issues. One is that the convertible power top goes down great, but its slow coming up and needs some assistance.

I checked the reservoir and its full.

I checked power to the motor and confirmed the switch on the dash is fine.

I also confirmed that the motor gets a full 12.8 volts at each feeder to it (two feeds from the switch, one for up and one for down). 

I also cleaned the ground but no change.

Should I assume the motor is shot and buy a whole new pump and motor. Or is it possible that the pump is leaking internally and needs to be rebuilt with new O-rings? I only ask this because I went on the Hydro electric site and found the pump/motor for sale. But also found a seal kit for the pump.

thanks
Tom

[Chryco Psycho]

I assume everyhting is lubed & free moving ?
 If so it has to be a weak pump system , I guess you could rebuild the pump but i have never done that

[sprecks]

Make sure the lines are vented of all air. Air in the lines would cause it to go up slow. Going down fast is normal since you have the weight of the top assisting.

[Finoke]

Hi Guys,
Yes the top mechanism is free and smooth.

I will try venting the lines, refilling the pistons first. The top was in the down position for many years.

I will disassemble the pump if that doesnt work. Maybe it just needs to cleaned internal?

Thanks and i will keep you posted.
Tom

[Jesus H Chrysler]

Have you made sure all your connections are clean, no green corrosion or dark brown oxidation in them?  My top operates the same way as yours, very slow to go up.  When I kick up the idle it gives it more power and can go up on it's own.  I checked my wiring (the whole car was butchered) and found some of my connectors were oxidized and not making great contact.  I cleaned them up and it improved slightly.  My next step is to run a dedicated battery hot with a relay to run the top so the power doesn't have to run through so many connections.

Btw I have another complete top pump assembly and before I removed it, it operated the same way, slow to go up.  I wonder if it's just the way it's designed?

[4Cruizn]

Just curious . . . is the car running when you are trying to get the top up?  Mine is slow but will get there under its own power . . .

[Finoke]

I guess I should also do a resistance test across the wiring, but honestly all the wiring on this car is pristine. The car has been garaged in this condition since 84.

I tried the top with the motor idling. Didn't think to speed it up to supply more juice. I will do a little more troubleshooting this weekend.

Tom

[Finoke]

I tried the top yesterday with the motor revving. But the it didn't seem to make a difference with the top going up. Still slow.

I bled the cylinders with the procedure on the hydro electric site. But still no good.

I'm going to clean up all the wiring connections next.

I did run across this article about opening and cleaning out the pump.....


http://autobodystore.com/forum/showthread.php?23148-quot-Basics-of-Basics-quot-Convertible-Top-pump-motor-disassembly-and-rebuild

[Got JOB]

Mine was slow also at idle, a little faster if the motor was revved up. I wired my top switch to the starter relay with a fuse in-line to get a better source instead of thru the bulkhead. It is better but I always operate the top with the car running.

[joelson6]

back in the day, i had a '66 Belvedere II convertible that had wiring issues, typical bulkhead rot. i'd be driving down the road
and i'd loose power on everything and i had to coast to the side of the road. the only thing that still worked was the top. plus,
my Fury conv. worked with the key off. does your's work with the key off?

why don't you try this for a test, disconnect the wires from the pump and get some new wires. connect them to the pump and then
connect the other end straight to a battery. you can  probably keep the cables short and use a jump box. see if that makes a
difference.

[Finoke]

Okay, I finally got the top going up without assistance. I answered a craigslist ad for a used pump/motor. I thought I would take that apart and clean / regasket it, instead of pulling mine out of the car first.

Well the seller was a nice older retired mechanic. He told me to try a trick first without replacing my pump. He told me to replace some of the fluid with seal conditioner and run the top a dozen or more times. He said that will swell the seals in the piston. He said he did that on his challenger vert years ago and it solved his problem.

So I pulled 4 ounces of fluid out and replaced with 4 ounces of trans fluid seal conditioner, leak stop. It was about the same viscosity and color as the trans fluid.

I ran it up and down a dozen times over the course of a week and it started to work on its own without my assistance.

I would recommend trying this first because it can be done without taking anything apart or out of the car.

Many thanks to retired mechanics!

 

[magicr]

I have nothing to add to this thread, except I think it's ironic that Jesus H Chrysler has 666 posts. Carry on.   

[soundcontrol]

Nice car! My top was the same, was sitting for maybe 10 years, before I bought it. I noticed a lot of air in the lines, so I filled up with more fluid, ran the top maybe 10 times, got some air out and lubricated all the joints in the frame, it runs way better now, but I still have some air bubbles though. Gonna try the leak stop trick also. How do you bleed the cylinders? I thought the motor will bleed itself by running it...

[Finoke]

I have nothing to add to this thread, except I think it's ironic that Jesus H Chrysler has 666 posts. Carry on.   

Hopefully it's pronounced Hey Suess

[Finoke]

Nice car! My top was the same, was sitting for maybe 10 years, before I bought it. I noticed a lot of air in the lines, so I filled up with more fluid, ran the top maybe 10 times, got some air out and lubricated all the joints in the frame, it runs way better now, but I still have some air bubbles though. Gonna try the leak stop trick also. How do you bleed the cylinders? I thought the motor will bleed itself by running it...

It's recommended to bleed the pistons of air without any load. So you need to disconnect the piston top from the mechanism. Then run them up and down.