Troubleshooting hydroelectric on seat in a '49 convertible

[Orin 16302]

Hi, all.  I have a '49 convertible with the hyrdroelectric system.  The system works well overall, and was serviced about 5 years ago, with a rebuilt pump and some rebuilt cylinders. (Still the original brake fluid, not atf, though.) 

I am having problems with the front seat, which is on the hydroelectric system, to move it front and back.  When I pull the switch forward, to move the seat forward, it works fine, moving the seat forward.  When I pull the switch back, though, to move the seat back, I just get a click sound near the cylinder in the middle of front seat.  Nothing else engages, no whirring of the pump, and no movement.  As a result, my front seat is pulled way forward and I can't move it back.

Any idea how to repair this?  Any thoughts?  Thanks very much for your consideration!

Orin
CLC Member #16302
Northern California, Bay Area

[G Pennington]

The pump is not activated when the seat is moved aft.  The switch energizes (opens) the solenoid valve at the base of seat cylinder and allows a large spring to pull the seat back.  The clicking sound you hear is probably the cylinder solenoid.  My guess would be that something is jammed and not allowing the spring to return the seat to the full aft position.

[V63]

The movement back is by purging fluid back and spring tension, similar to lowering the window. The pump does not operate in these scenarios. Verify that the valve is opening and that the spring is attached and seat not binding.

Keep the Brake fluid (not ideal) Frequently changed annually at a minimum. Converting to ATF will probably necessitate rebuild of entire system.

Also verify lubrication of the sliding track

If you can seat yourself you can try and 'assist' the assembly rearward by holding the switch rearward and apply some pressure with your body rearward? If you get no movement it maybe the fluid is not flowing

[Orin 16302]

Thanks for the replies!  I looked back at the rear of the cylinder, where the spring attaches. The spring appears to be attached, although I'm not sure what I should be looking for in terms of obstructions or if the valve is opening.   I've (hopefully) attached a photo that I hope shows what it looks like as far as I can see....

[V63]

You can pull out the seat bottom cushion for a better look and service.

[Brad Ipsen CLC #737]

As compared to the window lift units the seat unit also as a rachet affair that keeps the seat from jiggling in the stopped position.  In restoring a 49 I never did quite understand how this worked but it worked so i didn't worry about it. If all other items mentioned above check out you might study this feature of the assembly and make sure it is not blocking the unit from going back.