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Top cylinders replaced.. top won't operate..!

1K views 15 replies 7 participants last post by  bmorrow 
#1 · (Edited)
hello all..

on my R129 the inevitable occurred and some of the cylinders started leaking..

top hydraulics suplied rebuild cylinder and i replaced them all..
(well, the local dealer did three but more leaked and this seemed like a DIY project going forward)

SO, all cylinders are now replaced, the hydraulic tank is topped up with the proper oil..

but trying to raise or lower the top just results in it trying to latch the rear bow and thats IT..!

my question is is there a reset required or some other trick i need to know..?

thanks for any hints.. :)
 
#3 ·
thanks for this link..
i'll check those test points..

meanwhile:
there is a bundle of ground wires in the trunk next to the electric antenna that i forgot to reattach..

i DID reattach them to the ground and while the red light on the top switch now has changed its behavious the top still won't operate correctly..
but the roll bar and windows WILL go down when i try to raise the top but thats where it stops..

i should not the pump fluid tank IS up and the pump does operate..

i hope i did not damage anything when trying to operate the top without the ground wires all grounded but i'm not even sure those are associated with the top..
 
#4 ·
One of my friends just had the same issue. All cylinders replaced and the hard top was put back on. I brought the car home for her and tried to remove the hard top. The only thing that worked was the rear would release and relock.

I used the tool and manually unlocked and relocked the front and rear. It worked! I have no idea why, but now everything works perfectly.
 
#5 ·
One of my friends just had the same issue. All cylinders replaced and the hard top was put back on. I brought the car home for her and tried to remove the hard top. The only thing that worked was the rear would release and relock.

I used the tool and manually unlocked and re locked the front and rear. It worked! I have no idea why, but now everything works perfectly.
Using that tool you triggered one of the limit switches, then system came to life, I would do the same , if still an issue , clear codes, but on your year I'm pretty sure you need a dealer with the right setup to read and clear codes.
 
#7 ·
If the rear of the soft top is unlocking and lifting, and the tonneau cover stays down, you may have installed the head of the left bow piston backwards. To a quick glance, it appears symmetrical, but it is not. It is shaped so it is larger on one side than the other. The larger side is to activate the switch. If you have it backward, it will not activate the switch, ever.

I made this mistake myself the first set of replaced pistons.
 
#9 ·
thanks for the hint
with all the talk about crushing the microswitch this was one thing i was careful with..
and i was sure that the wider surface was facing the microswitch..
which, BTW, was soaked with oil from that leaking cylinder..AND has a membrane of a sort that looks to protect the switch from oil intrusion..

this is one thing i'll check with a multi meter when i put the star diag system on the car..
 
#8 ·
2 other things:

1) You have to initiate the soft top from a completed cycle position. This is where to start. (that and making sure you re-sync the windows)

2) When I replaced my first set of pistons, even after fixing all my mistakes like the one above, the pistons didn't work properly. So I manually locked the hard-top on the car. After about 2 months, for giggles, I tried to remove the hardtop w/the control button and VIOLA!!! The system worked (almost) perfectly ever since.
 
#10 ·
also a good hint..
so i tried with the soft top fully folded down..

if the stuff i'll try (see post just above) does fix it i'll just put the hard top back and take it to a dealer.. :surrender:
 
#11 ·
I've also found that if for some reason the system gets confused, like stopping partway in the cycle and then the top moving, working on the top etc. the controller can end up stopping the top part way through the cycle.

My solution was to manually raise the top locking the front but not the back, then manually lower the top completely into the boot and drop the tonneu cover. Don't recall if ignition was on or off, but I think on. then try to raise the top. worked for me. I think the manual process may get the switches opened and closed in a sequence that the controller thinks is correct and let's everything function properly again.

Lesson since then was to be very careful with partial open or closing of the top and if stopped in a given position for some reason, to not let it change positions, especially with the ignition on.

And then being paranoid, I always have the engine running and in park when I open or close the top or release or attach the hardtop. Supposidly not necesary, but IMHO a worthwhile precaution.
 
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#12 ·
HAH..
oooohh kay..!

did not need to use the star diag (phew!) or test the microswitch..

the final solution: latch everything manually with the top UP.. then press the top button to lower the top and VIOLA! it WORKED.. some clunking and snapping but it put itself down and closed up and raised the windows and put the roll bar back up (if it started out with the roll bar up!)..

i cycled it a few times and watched the reservoir fluid level drop to just below the add line..
i guess most of the air is now out of the system.. and i'm going to start buttoning the trim and so forth back up..

does anyone know if new putty or glue should be used under the bose whoofer..? or is it ok to just plokn the whoofer back down on the old putty/glue and assume there won't be any vibration occurring..?

so, gentlemen, i guess the key is to start from a known position with everything latched and locked..

sort of like rebooting your computer when windoze locks up or becomes slower.. :)
 
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#13 ·
glad you go it working. like you found out, manually operating the top seems to get the controllers attention and get it back to working often. Again, I suspect it had a switch position stored that didn't match the top position and manually cycling it get's it synced back up again and working as it should.
 
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#16 ·
one further note guys..
i exercised the top again today AFTER adding more oil..
then i took a turkey baster and sucked all the oil out of the reservoir and dumped it into an empty water bottle..
as i sucked the oil from the bottom of the reservoir i noted that it picked up some sediment..
looking at the oil in the clear plastic bottle it appeared unclean.. not clear..
SO, my advice is if you do all your cylinders get rid of as much of that old oil as you can..
i got the mercedes branded oil for about $16 a liter/quart..
all the work i did "cost" that one liter..
to get the free shipping i bought 5 liters..

thanks for the advice on the glue for the woofer..
i thought they glued it down to prevent any bass rattling..

[trivial ramblings here]
so i have a lot of spare hydraulic oil which i can use, i suspect, in the SL55 and maybe in the S600 which i still think is only good for parting out but for a car that drives as great as it does i hate to do anything other than fix whatever causes its engine issue and either sell it for $3k or $4k.. way too nice a car to just rot away..
 
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