Thank you, sir. I've tried my eight-pound sledge. There were, uh, side effects.

I agree with your analysis. I'm seeing this: at close-top time, in a stock system the top parks a centimeter or so above the windshield frame and is then pulled down by the latch. Then, when we open the top, it sort of wants to spring back away from the windshield frame, and the microswitch is tripped. Acting a little differently with manual latch ... not sure yet why.

Favor please ... would you read the stuff near the bottom of my post (page 47, I think) about deadheading. You OK with this?

 

Great stuff, Dennis. Thanks for your persistence on this project....

I want to convert my wife's XK8 to your system. She does not (I wish she still feared the green shower as much as she did when I first informed her of it soon after we purchased the car in early February 2012). Since it is her car, she wins for now. But if the green shower strikes, all bets may be off....

If you decide to sell $8 kits, I would like to purchase one from you as an insurance policy....

Thanks again for your determination to find a way around this dilemma....

 

Thanks for the kind words, Jon.

I had ordered a few sets just to get over their $25 credit card minimum. After yours, 2 sets are left. (I have your PM).

If there is interest, maybe we could put together a bulk order.

 

Dennis,
I'm honestly not sure.
The pump does run up against the stops when the latch operates, that's what bursts the hoses so I don't think you're doing anything worse.
Lanny's system has survived!

 

Thanks.

I was thinking too of all the cases where guys have had things stall, get stuck, etc. with the pump pumping away for seconds or tens of seconds against a deadhead. The pump itself seems pretty robust.

Still, a shunt hose instead of port caps would be 100% safe, wouldn''t it? I need to look into that.

And I just realized what that picture was you posted this morning. Purty!

 

I really don't know, but my instinct would be to stick with what you have.
The caps are mimicking what would happen with the hoses connected, a link would provide pressure to the other side where it normally wouldn't see it.
Would that cause any problems?

 

Sent you a PM on a set of plugs Dennis. Thanks Mike

 

My thought was to create a path for fluid there to substutute for the path through the latch (that is normally present). It would prevent a deadhead for sure, but if it were too "wide open" ... other headaches.

I could maybe experiment with my own car a bit (after a suitable "enough already" period).

 

I wasn't imagining a path through the latch, if you apply pressure to either open or close the latch the piston will displace the fluid as it moves then create the dead head pressure on one side only when the stroke is complete?

I'm just thinking out loud here Dennis and don't want to clutter up a useful thread with a lot of speculation.

 

Thanks Denis Good work! I sent you a PM regarding purchasing one of your kits

 

No problem at all, Norri. As I understand it ...

Stock system, yes a deadhead occurs at the ends of the latch piston travel ... when the latch has been fully raised or fully retracted. This deadhead lasts some fraction of a second, until the electrics shut the pump down.

With manual-latch, the pump is in deadhead for the entire time it thinks it is operating the latch piston since there is no such path, just port caps.

The evidence we have says to me that deadheads in this system have been damaging only to latch hoses, which of course are out of the picture with manual-latch. (If it goes on too long, a deadhead can heat up the pump, but I don't think we're in danger of that here.)

 

All of the fittings that I ordered in first batch are spoken for.

I wonder if someone who knows how to do a poll here could scope out how many might want to be part of a bulk order??

 

Is the period of dead heading under stock operation prolonged while the rear windows operate? I installed a separate switch to lower and raise the rear windows with the top down and have gotten in the practice of using the switch instead of the convertible toggle switch in hopes of decreasing the dead head time. So if the pump is designed to deadhead for a period of time to allow window operation maybe the combination of rear window switch and plugging the latch ports makes the dead head issue moot.

I hope this makes sense.

 

Was I the first one to recommend that these systems should have been semi-manual? Regardless you have done a yeoman effort of investigation and implementation.

If you are going to put together a group purchase for these kits I would buy one just so I have something as a backup if and when leaks might occur.

Thanks,

Doug

 

Perfect sense. But I think you have the same deadhead situation with or without the window switch. Deadheads occur each time the latch is opened (beginning of both raise-top and lower top operations) ... and each time the latch is closed (end of raise-top and lower top operations). But in no case is a deadhead prolonged while the windows operate. They last some fraction of a second in all cases (if I remember the graphs right without looking).

Now: did that make sense?

 

The pump is not on when the windows operate.

 

i am in awe of how much effort you have put into this Dennis, and as I understand it your top is not (yet) malfunctioning! My hat is off too you. And yes, my pump is still a happy camper after being plugged for who knows how long. I have never known "the wonder" of a full functioning top system with latch. I have two classic Thunderbird convertibles and I am used to reaching up and latching or unlatching when I raise or lower the tops.
Now if I could only I could get rid of the "top not latched" message. Although I have no intentions of selling my car, someday it will be a major drawback if I do. And, it is annoying.

 

Thanks, Lanny. Yes, my top still functions as advertised. Knock on wood.

I can't recall the details of the hack done to your car by the prior owner, but I think that may be why you can't lose the "not latched" message. One of the modules, I forget which one, tests for latch closure as it is completing a top raise/lower operation, and as I recall, your pump has been wired around the modules so they never know what you're doing.

Could that be it? How much work to put the wiring back to stock?


It's all relative, right? On my MGA, you have to pull the tonneau, wrestle the top frame to the up position, and install the side curtains. I've been doing it a long time and can now get it done in under 20 minutes.

 

Edit: sorry, all of the caps for the hose ports that I had are gone now. Vendor information is found in the "manual latch" link in my signature line below.

It turns out I have one remaining set of caps for use with manual-latch (used to seal off the hydraulic pump hose ports that connect to the latch). As discussed in post #98, this thread.

$8.00 for a set delivered, no profit in there. PM please if interested.

 

Dennis you are the man! I got my plugs in, topped off the Pentosin, and raised the top! It worked great. Many thanks for your hard work finding the correct fittings and getting them out to me.

Just one thing I did wrong, I knocked the filler plug behind the pump, when I unscrewed it! It's down in that fender slot. Will have to pull the cd player out or whatever.

Now I'll wash my car more often, with the top easily raised.

Regards,

Don