Porsche Enthusiasts Club Forum

Note: This procedure assumes that you have purchased a new system and that your existing hydraulic lines and actuator assemblies are intact and usable. It’s better than my first attempt because it reflects the method used to assemble the device when it was made.
1 – Dismantle existing system. Be very careful when doing this as some components may be brittle with age. Carefully remove the brass inserts from the old actuators and re-use them in the syringes [ see photo 1].
2 – Dismantle the new system. Check for grease contamination of the plunger assembly and thoroughly clean if necessary. [see photo 2]
3 – Use the syringe with the brass insert to flush out the existing hydraulic lines with air.
4 – Dismantle and re-assemble the new plunger assembly. Do this several times as so you become familiar with how it goes together and how it operates. There are a number of components that have to be aligned for it to work correctly. [ See photo 3]
5 – Attach only the body of the new plunger assembly to the existing hydraulic lines. [I used a heat gun and pliers to make this job easier].
6 – Make sure the new plunger assembly is supported in an upright orientation and inject the existing hydraulic lines with new hydraulic fluid from the actuator end. Make sure no bubbles are injected. Fill to well above the piston chambers.
7/8 – Flush the new actuators so they are bubble free and connect them to the existing hydraulic lines. [I used a heat gun and pliers to make this job easier]. Make sure there are no bubbles trapped in the lines during this operation.
9 – Carefully drop the two rubber pistons into the piston chambers blow the fluid level and move them down into position so they are flush with the top of the chambers. Make sure they are the right way up and level! Some excess fluid maybe expelled from the over flow pipes so be prepared to catch this in a cloth. Once the pistons are in position you can syphon off any excess fluid above the pistons but leaving a small amount of fluid here will not interfere with the operation of the device.
10 – Re-assemble the screw assembly in its fully withdrawn setting including the final fixing that goes down the center.
11 – Test. The actuators should now operate in accordance with the measurements given in my previous posting and there should be a click at position ‘0’. If not then you may have assembled the plunger incorrectly. It’s possible to take it apart and try again without effecting the hydraulics which will now be sealed.



I will add some more photos later.

Ben

Photo1

Photo2

Photo3

Wow Ben
Great persistence with this Hydraulic lift system for our headlights - have to admire your persistence!
Great photos & write up's

Steve

Hi Steve, thanks.

I had forgotten about this thread, then noticed it was getting a lot of visits [ probably from other 928 sites ] so I though I'd better add the photos!

Ben

What a write up!

I need to do this on my car but there is a few things stopping me -

- Exactly what oil to use and how much
- Messing around under the wheel wells for access to the actuators

Pure guesswork here but is there a reason you can't just fill from the headlamp end and draw the fluid into the piston/knob assembly by winding the screw in fully and then out again (in-out-in-out etc) to bleed it, top up and then once you know there is no air in it push the tubes back on to the actuators?

Or is there a fundamental reason this won't work that I'm missing?

Any advice before I tackle this would be appreciated!

Llew

Hi Llew

- use 10wt silicon oil [ can be found in model car shops - they use it in their miniature dampers ]

- you only need to remove the wheel / wheel arch liner [ you will need to replace the sponge seals / Widely available / cheap ]

- I can't answer you third point as it depends on if its and old or new system you're working on and what state its in? From what you describe you wouldn't be able to tell if you had an air lock in the control assembly or if was contaminated with dirt / grease - better to start from scratch so you know - Even the new system I was supplied was badly contaminated so you can imagine what a 30 year old system could be like.

Ben

Thanks for the info Ben! I've just order a litre of 10wt fork oil, should be plenty! ))

I'll have a play next time I get a chance and let you know how I get on...

Are the little pointy bits on the plastic housing for filling?