rich5962

Edit....Go HERE to post#45 see it working after I rebuilt it. Read on to see how I fixed it.

Posts 75 & 77 have pdf conversions of this thread.

I am considering getting it working. I have to adjust the soft top and fix some previous rag installation errors by the installer.

Has anyone here used DOT 5 Silicone fluid in a power top? I have to take everything apart and flush it and see how it looks inside, so maybe that or ATF would be a better choice. This top motor/pump and pieces are in excellent exterior condition. I think it's dry inside there.

Between this, the '61 windshield washer rebuild, and my first FI unit rebuild, and other crazy projects I have on my plate, I think I may be in new found migraine territory.

Here are some pics of the PT stuff.

wmf62

IF i remember correctly, silicone fluids have a propensity to release trapped air VERY slowly, so it might be a real pain to bleed it. ATF would be my choice.
Bill

rich5962

Ahhh, good point Bill. ATF it will be. Cheaper too if I blow a hose.

mike coletta

Hey Rich,
I've done a few of those in my day, and would offer the following. Don't bother to try and make it work if it has not been used recently. Put new cylinders on it. I promise you that the old ones are no good. Disassemble the solenoid valves, and get them working on a bench. Same with the motor/pump. Change ALL of the rubber lines. Make sure that all of the switches are working and adjusted properly. Good luck with that one. The system is very cool when it is working correctly. Make sure that you unlatch the decklid and the header before you pump it up. New side cylinders are a must to get them to pull evenly. At least that has been my experience. Good luck. You'll be drinking before it's over.

Mike Coletta

BTW, I would use ATF.

1955 copper

solenoid valves lower covers and motor painted black tells me it's been apart before and may be in working condition

3310vette

Rich, are you sure that the original brake fluid was purged when the power top was no longer used? If not, the brake fluid turns to brown, sandy crud that will plug up the solenoids if pieces of it break off. I worked for 10 days to clean out this crud from my 1960 cylinders and was not successful. A couple of other considerations, it appears that the equipment has original hoses and maybe the wiring harness. I think it is risky to use the old hoses and run the risk of having a blow out; even with ATF, not a pretty site. If the wiring harness is original, you run the risk of a short or melt down. Even with a new wiring harness, the wires get hot every time the system is run as it is a high amp system. I considered using the original hoses and wiring, but listened to several associates that convinced me new parts were the safest way to go and now glad I went that route.

Using the original motor and pump is a different potential issue. Old motors and pumps may work, but seldom do they raise the top in the same time as when new (22-24 seconds). I purchased a new pump/motor and on a warm day, it will raise in 24 seconds. You can always try your existing equipment first and decide if the speed is acceptable to you.

JohnZ

Here's an article I wrote on the subject several years ago that you may find useful.

http://www.lbfun.com/warehouse/tech_...ower%20top.pdf

3310vette

I wish I had your article 2 years ago when I installed a power top on my 1960 with almost no help except what the ST-12 contained and the diagram in the 1960 AIM. It took me about a month, but I made it work and 2 years later is still works. It is still fun to watch it work and it is always the hit of a car show when I operate the power top.

emccomas

John;

The 56 power top system had some different parts, if I recall correctly. I don't recall any limit switches. Can you elaborate.

Ed

JohnZ

The limit switches (and "safety switches") were used in '56 and '57, although with minor functional and location differences - they essentially were "timers" for the solenoid valves. Both are shown on page 60 and 61 in the NCRS 1953-1972 Corvette Electrical Wiring Diagram book, and in the Power Top chapter in the ST-12.

emccomas

Thanks John

rich5962

Hi All....Just got home. Wife and some of our friends took birthday boy out for dinner. Technically the 12th, so I have about a hour or so before the next decade of life begins.

Thanks for all of the great info and suggestions. I'll be taking it all in if I'm going "in" with this.

Mike, yes I need to learn how to drink anyways, so now may be a good time.
John that's a great article, thanks. I read it while waiting for the other half to get ready for dinner.
Joe, I recall the effort you put into that top on your '60. Nice work. I still have to get some of the pieces off to see the status of the system.
Roy, good point. I'll probably take some of the pieces apart to see what I have. If I do, I'll be posting up the progress here.

When I proceed with some basic tests and it looks feasible, will probably go for new cylinders and hoses, and new wiring if it checks out as marginal. My local NAPA can make the hoses for me. But the owner, a friend of mine, has the call.

Thanks,
Rich

Panama 58

John and Ed, although I have heard comments that '56s had limit switches, #3241 that I restored did not. The PT pump had been either replaced or restored, but all of the safety switches, harness, triggers, etc. had not been touched and there were no signs of prior attachment holes or mounts for limit switches. LectricLimited guys swore that both '56 and '57 had limit switches, but I could find no proof on my '56. Your article also describes the trunk safety switch as being on the right side of the inner trunk. You may have been speaking specifically of the '58 in the article, but to be clear, the '56 trunk safety switch was on the upper left side and the '57 was moved to the right, upper side. As Ed commented, there were some slight differences from '56 to '57.
Panama58

emccomas

I didn't find any evidence of limit switches on my 56, #2117 either. That is what got me wondering about it.

The trunk safety switch was on the upper left side of the inner trunk. I personally removed the switches from this car.

3310vette

Call them what you will, but all of the power top units from 1956 to 1962 had micro switches or limit switches that activated or deactivated the solenoids. In the photo above, you can see the pin type limit switches that were activated by a metal "arm" attached to the deck lid cylinder rod.

vettebuyer6369

At Kissimmee in January...

3310vette

Rich, it probably won't make any mechanical difference, but the motor/pump/reservoir in your photo is mounted in the opposite position of any power top system I have ever seen. Motor is typically mounted on the left with reservoir on the right.

Joe

rich5962

Yes, I don't have a clue why it's different. It looks like it's been there a long time, however as Roy noticed, it's probably been out for rebuild/repaint at one time, which may be a good thing.

Okay, so this morning I've been playing with switches. Tested the right compartment toggle limit switches, and the inside trunk toggle limit switches. All good. BTW, these are totally different than the later '57 switches I see in the '57 AIM, as discussed above.

The decklid safety switch failed it's test. It's a DPST(double pole single throw). I took it apart. As you can see, the contacts were open/bent outward. I re-bent the inner contacts, cleaned all contacts with my Industrial Eraser made for gold/copper contact cleaning, peened the loose rivets on the terminals, put it back together and it's working fine now.

More to come, but I suspect the trunk lid safety switch may need the same work. Same design. It's contacts are susceptible to bending probably due to the heat of current flow. This system could really use relays to reduce current in the switches. Likely too pricey for them in the 50's.

Rich

rich5962

Yup, as suspected, the trunk safety switch had the same problem. Open contacts. This one is a SPST(single pole single throw), with a slightly different contactor on the plunger.

Same procedure as the decklid switch to fix it up and get it working again. I found the manufacturers mark on this one, D in a triangle.

Anyone know who that was?

(I may be rearranging deckchairs on the Titanic again, but we'll see how it goes.)

rich5962

Okaaay, here we go. Tried the top for life sounds. Bypassed the trunk saftey with a jumper to hear better. left the trunk up a bit. Moving the switches around in their normal/abnormal positions for "top up/down" cycles, I can hear solenoids and clicks.

The motor is seized. Tied direct, it's seized. Pump tank is dry and empty.Yanked it out, tore it apart. I see the problems, lots of corrosion, but nice overall condition. I will rebuild this myself. Done others like this before, but later equipment.

Let's see how it goes.

Rich