Convertible Power Top Pump?

[Iplayfarmer]

I've got my eye on a hydraulic pump from a power top from a convertible car.

What kind of pressure and flow do these units usually produce? Anyone Know?

 

[sandman2234]

Probably enough to power a convertable top for your tractor, but other than that, what do you have in mind for it? I wouldn't guess the pressure, but the volume is probably pretty low.

David from jax

 

[Wayne County Hose]

It's not worth bothering with. Low flow, low pressure, low capacity. Might be good for a dump cart on a lawnmower wagon, if that.

 

[Iplayfarmer]

...what do you have in mind for it? I wouldn't guess the pressure, but the volume is probably pretty low.

David from jax

I was thinking of using it to power a light weight dump. I've got a power pack for the garden cart I'm building, but this convertible top one is real compact and has electric controls allowing me to build a remote control for it. I wouldn't need a lot of flow, but I'd need some pressure... ~1500 -1700 psi.

I can't find any specs for pressure or flow anywhere for these pumps. Just year, make, and model for the car they came out of.

 

[Wayne County Hose]

Wow, that might be a neat little project. If you would like to mail it to me, I could do a max pressure check for you. Or, you could get a gauge and plumb it from the inlet to the outlet with a high pressure valve after the gauge. Turn it on, slowly close the valve (but not all the way) until you get your pressure relief kicks out.

Also, check the pressure rating on the line they use. That could tell you something. If they use tube rated for 500 p.s.i., you know it won't work. If I remember correctly, my Camaro convertible had clear plastic tubing, not much pressure there. I think this is worth checking. Inexpensive and easy, just like a good woman.

 

[Iplayfarmer]

Well, I went ahead and bought the pump. $40 dollars will either buy me a good useable 12V hydraulic pump, or it will just buy me an education about these convertible top pumps.

I figure it's worth the risk.

Knowing me, if I don't use it for what I have in mind, I'll just use it for something else later.

 

[sandman2234]

You can always sell it to someone wanting a power top on whatever kind of car you took it off, to recoup your money.
David from jax

 

[Iplayfarmer]

I got the pump yesterday in the mail...Finally.

I was hoping there would be some markings on it as to the horsepower, specs, etc. but there's just a brand name and serial number. I may have to get me a hydraulic pressure guage. I could use it for a number of things anyway.

The issue I have now is that the pump has two wires. Red to + and Black to - turns the motor one way. Red to - Black to + turns it another. I'm having a hard time getting my head around a switch that will easily do this.

Any reversible motor I've played with has had three wires. One is a ground and then power to the other two will turn the motor opposite directions respectively.

 

[Wayne County Hose]

How about going to a junkyard and getting the switch and relay from a convertible. You will need a relay anyway, might as well get the one made for it.

 

[Iplayfarmer]

How about going to a junkyard and getting the switch and relay from a convertible. You will need a relay anyway, might as well get the one made for it.

I don't know if I will need a relay. The wires going to the pump look to be either 14 or 16 guage. I'll probably just run power directly to the switch and then back to the pump.

I talked to our in-house electrician at work and he taught me how to cross jumper the connections to a Double Pole Double Throw momentary rocker switch to make it work. I think I've even got some 4 conductor wire that I saved when we scrapped an old treadmill for the DC motor (generator) that was in it.

 

[elad]

Many years ago,[60s I think], I used the convertible top pump, cylinders, and
control to raise and lower a 6ft. snowplow blade. Had to pump it up and pump it down. I could stand on the blade and it would still lift it. Car was a Chevrolet; early 50s with a 6 volt system. No idea of the pressure that it made. But, I do know they worked. I built 2 of them. One for the Butter Krust Baking co. service truck, and one for me. I used both cylinders and never
opened the hydraulic system. The cylinders may of been 11/2" or 2". not sure.
It was long ago. The push rods were quite small in dia. so they had to push
straight up so as not to bend them. The system was more powerful than
I would of thought. Didn't mean to rattle on so long, but the topic brought
back some memories of the past. You might be surprised with there usefullness. GOOD LUCK
elad

 

[Iplayfarmer]

Many years ago,[60s I think], I used the convertible top pump, cylinders, and
control to raise and lower a 6ft. snowplow blade. Had to pump it up and pump it down. I could stand on the blade and it would still lift it. Car was a Chevrolet; early 50s with a 6 volt system. No idea of the pressure that it made. But, I do know they worked. I built 2 of them. One for the Butter Krust Baking co. service truck, and one for me. I used both cylinders and never
opened the hydraulic system. The cylinders may of been 11/2" or 2". not sure.
It was long ago. The push rods were quite small in dia. so they had to push
straight up so as not to bend them. The system was more powerful than
I would of thought. Didn't mean to rattle on so long, but the topic brought
back some memories of the past. You might be surprised with there usefullness. GOOD LUCK
elad

Thanks for chiming in.

I went to the auto parts store to have them help me determine what size and standard the threads are on the pump. It definately isn't NPT.

The guy at the store recognized it immediately as flared fittings like what they use on brake lines. Sure enough, a test fit with one of his ends fit perfectly. He quoted me about $60 per line for a few 5 foot custom hoses to connect it to the ram. I am pretty proud of my self control for not choking out loud when I heard that.

Now I'm on the prowl for a cheap way to get flexible hose to go from the flared fitting on the pump to the NPT fittings on the ram.

Keep in mind that this whole process is more academic that anything. I just want to see if it works and if these convertible top pumps are a good, cheap alternative for home brew hydraulics.

 

[cleatus]

You could use the steel tubeing and short rubber hoses that go to wheel cylinders, then you can adapt up to larger NPT.

 

[Iplayfarmer]

I just spend an hour searching the internet. What do they call those flared fittings that go on brake lines?

Here's a picture of the threads if it's helpful.

I've seen AN to NPT adapters, but the AN doesn't look right. I think it might be inverted flare, but there's very little out there about inverted flare fittings by that name.

 

[Willl]

Did the fitting look like these ?

If so, I've seen pre-made 4-5' straight ones at the auto parts store.

 

[Iplayfarmer]

Did the fitting look like these ?

If so, I've seen pre-made 4-5' straight ones at the auto parts store.

Just like that.

What I need is a way to get from that fitting to the 3/8" NPT on the cylinder cheaply enough that it can still classify as an experiment.

Surplus center has a bunch of SAE O-ring adapters. Does anyone know if these will work?

How would I determine the size I need?

 

[Iplayfarmer]

...And what's the difference between a Straight Thread O-ring Boss and O-ring Face Seal?

 

[Wayne County Hose]

...And what's the difference between a Straight Thread O-ring Boss and O-ring Face Seal?

Straight thread o-ring has an o-ring that goes over the threads, flat face o-ring has an o-ring that goes on the face of the fitting, between the flat faces of the male and female. O-ring adaptors will not work.

What you have is inverted flare. If you go to a Napa store, or search for Weatherhead distributors on the internet, go to the brass connector cabinet. Look for part # 252X..... This connects inverted flare to female pipe. You will need a short piece of brake line to go from your pump to this connector.

 

[Iplayfarmer]

Thanks to the great advice from Wayne County Hose, I got the adapters I needed.

I love TBN!

Now I can't wait to get off work and try everything out. I just want to see what kind of weight this little pump will lift.

 

[Iplayfarmer]

Here are the results...

I got the hoses all hooked up and the pump filled with transmission fluid. The empty bed of my almost done dump cart moved smoothly, but much more slowly than with the larger pump.

I have 280 pounds of olympic weights and I added them about 100 pounds at a time to the very front of the bed. By the time I added the last 100 pounds it was obvious that the pump was starting to work hard. It didn't heat up at all, but it sounded like it was working hard and it was moving the dump bed a bit slower.

I moved the weight back a bit to the middle of the dump bed and the pump seemed to have an easier time of it.

I have a 2" X 24" ram on the dump bed. It has a 9.5" rise. With these dimensions, I figure that in order to lift the weight of the dump bed and the added weights, the pump has to be producing at least 300 psi. My guess from what I observed is that the pump will probably push about 500 psi.

I think I will install this smaller pump in my little dump cart. It should lift most of what I'll put in it. If I get to the point that I'm overloading the little pump I can always put the big one back in. The convenience of the electric controls will be nice.