danfil

I have been reading into why my cabriolet roof does not operate automatically and read this post..

https://www.audiworld.com/forums/aud...rking-2804878/

And so without a vag com I have changed out the N90 and N91 valves on my hydraulic motor since the were burning hot when I was first trying the roof to operate. I swapped them with the N88 and N89 valves. All four were removed without a problem, but re installing them was, so out again looking for the spring as pictured in one post by 'hubturn' at the bottom of the valve. So to be seated properly, instead finding a ball bearing and "spacer" arrangement which confused me a lot. They all seamed randomly placed below the valve in an unordered state. In the N88 and N89 I found no spring or ball bearing but when putting these back into N90 and N91 I found the spacer spring and ball bearing.

Any how if any one can shed some light into how this arrangement works, it would be greatly appreciated.

N.B. Will advertise on an Aussie site for some one with Vag Com, not going to go to a dealer, for the diagnostics.
I think I made it worse ( the roof operation ) since I tried it earlier today before the valve swaps and the windows came down the required level for the roof to come down after using the roof switch, now the windows do not come down and the switch does nothing.
Never any lights on the dash showing roof coming down.
All valves are seated properly.
I am working in the boot, I have tried and tried to get the electrically powered hydraulic motor out for bench work and failed and failed. Most recently by trying to swivel the fuel tank, by pivoting on the left and sliding the right side of the tank after removing straps on plastic fuel tank. The fuel tank is in there tight, so I cannot access the front bolt on the motor to release the thing ....

Rusty Spokes

Don't know if this will help..it is in German..a self study guide for the top. Google translate will help.

http://www.volkspage.net/technik/ssp/ssp/SSP_156.PDF

Baumeister

Have you made any progress? I finally decided to deal with my leaky pump today. I've had the replacement reservoir and o-ring for several months.
To get to the front pump bolt does require some maneuvering of the fuel tank. Here's what I did:
1. Unbolted the evap container mount under the car(Right rear, 2 10mm head bolts) but did not disconnect any of the hoses.
2. At the inside of the fuel filler, removed the electrical ground spade connector, then pushed out the fuel filler rubber surround. (left it attached to the drain hose. There is a wire around the perimeter, I only partially removed it from its frame.
3. Unbolted the fuel tank straps at the middle of the tank and the mount(4 bolts total)
4. Opened the top halfway(Trunk closed) and opened the convertible top cover. Pulled back the liner, and removed the 2 large plastic caps for trunk/tank access.
5. On the left hand side trunk access (from the top storage compartment), loosen the hose clamp and remove the hose from the tank.
6. On the right hand side trunk access(from the top storage compartment), remove the tank sensor electrical connection.
7. From the trunk(Top storage compartment completely closed) Start to lift and pull the fuel tank towards the rear of the car and towards the left hand side.

When you have the tank moved enough, you will be able to see the front top hydraulic pump bolt from both the top compartment right side access hole and the fuel filler location. It's a 13mm head bolt.
I got the tank moved enough(without draining) to use a standard 3/8" ratchet to remove that front bolt.

danfil

If that is how it is done then that's how its done,

I have a full tank of fuel so will be driving to reduce this before trying this.

But gives me a great reference to get the hydraulics out .

Rusty Spokes

I pulled the pump on a 1998 Cabriolet at the boneyard. I removed the rear bumper and a rubber plug to get to the rear pump mount. I used a 13mm short closed end wrench..and a 1/4 inch drive ratchet with a 13mm socket and reached the front pump nut from a port/hole in the chassis frame rail in the trunk. Look on the frame rail just inside the pump and attack the nut from the inside/under with your wrench/ratchet. I did not need to remove the fuel tank.


Disconnected the electrics and removed the pump hose connector block and lifted the entire pump unit out. No other brackets or hardware were needed to be removed.

There are two pumps for the Cabriolet..an 8 valve and six valve pump. The number of hoses/lines remain the same on the mounting block. The controller is different between the two pumps. The six valve pump is the replacement part now from Audi. (the part number on the 1998 Audi pump is 8G0 871 611A and is a six valve pump) You can tell how many valves you have by the number of solenoids on the top of the pump.
As a substitute for the early 8-valve hydraulic pump, a 6-valve hydraulic pump is supplied as a replacement part. When replacing the early 8 valve pump hydraulic pump, you must replace the control unit and an adapter cable concomitantly (part no. 8G0 871
791 E). I doubt Audi sells many..it would cost a fortune.

Baumeister

Rusty, does the '98 have a port along this beam? Or am I looking in the wrong spot on my '94? <br/>

Rusty Spokes

Is there an opening just forward of the beam in the picture, like under or in front of that brace on the left hand side? Should be an attack opening there somewhere.

Baumeister

I just checked thoroughly again...nothing until the end of the beam at the back seat, and then only a slight opening way too far forward.

Rusty Spokes

Looks like Audi made a change in the later cars..the 1998 has a port you can fiddle the front nut loose with:



Without that port..yes you have to get the fuel tank out of the way

Baumeister

AHA! Thanks for clearing that up for myself, Danfil and others with earlier cabrios. It's been very frustrating trying to figure out how others were getting that pump out relatively easily! On the back end nut though, I was able to loosen that one with an open end wrench. (no bumper removal).

Hope it's of help to the OP. I topped up my pump again yesterday and no signs of new leakage around the pump. The old plastic reservoir did not appear cracked, so I'm hoping it was the reservoir o-ring that was the cause of leakage on mine. I received my new rear window from cristal-cabriolet today, I've been cleaning the top in preparation for the new rear window, hopefully I'll get it zipped in tomorrow.