1990 500SL top motor - PeachParts Mercedes-Benz Forum

#1 07-07-2003, 10:40 PM

My 1990 500SL top (soft & hard) operates slowly. SF MBZ told me the top pump is by-passing fluid and needs to be changed. It still can be operated with the switch but, I need to manually lock the windshield locks. FYI the pump costs 2K.

Thanks to anyone with insite.

Eli (NJ) · #2 07-10-2003, 01:37 PM

Do not change the pump, again, do not change the pump. You have the same exact problem I have. The top is slow likely due to a leaking header bow lock, which is about $130 new. It lets some of the fluid get bypassed and so the top doesn't get all the oomph. I just live with it because I'm not sure which one (or both) it is, and it does lock now after adjusting the top hooks. Do a search on my screen name, many top posts covered.

Eli.

#3 07-11-2003, 12:01 PM

Thanks Eli,

I'll take a closer look at the latches. And if it still leads to the pump I'll take the advise of others rebuild it.

Gilly · #4 07-11-2003, 08:31 PM

Hi guys
You need to remove the trim piece that goes across the top of the header, it's only 4 screws. 2 you can see, these are the ones that hold down the black covers around the latch. The other 2 are on either side, under the weatherstrip, then tap it towards the rear to remove it.
Now attempt to operate the top, I recommend holding it in the "close top" position for 10 seconds, then move the top rearwards. The defective hydraulic cylinder will feel quite warm compared to a "good" one.

Gilly