Boge strut oil level and type

[Ian Comerford]

I am getting towards the end of a full suspension refresh on my 79 SC and have just stripped the front Boge struts for a repaint. I was surprised to find that the strut and insert operate on what I would call an open bath principle in that the insert is not a sealed unit and sits in oil in the strut housing. They seem to be working fine so i am going to refill and refit but do not know what the oil capacity or type is. Could anyone please help with this detail

Thank you

Ian

[bfunke]

I'm not aware of any "open oil bath" in the Boge strut. Some people used to pour some oil into the strut believing this helps dissipate heat from the insert to the strut housing. My car has Bilstein inserts and they recommend not using any oil. Someone correct me if I'm wrong about this.

Bryan

[Tidybuoy]

When i replaced my Boge strut inserts on a BMW many years ago, the directions called for ordinary motor oil and was explained as being needed for cooling. It only took a small amount as it is just filling the gaps between the strut and the housing (1/2 cup at the most).

Vern

[Two Rivers]

We used ford type automatic trans fluid back in the day we rebuilt these type of struts.
You can use hydraulic jack oil also but we thought ATF was better.
The strut was filled about three fourths full when the piston was in so there was expansion room.
I am surprised they are working proper as they use the strut tube as the cylinder and it is a soft metal and wears at the contact areas.
They where rebuilt once with a no guarantee signature from the customer and would have to be replaced with cartage type most of the time.

Now days I would think they would just be replaced with cartridge type.

Note: the ford ATF was the old type and I do not know about using mer-con type ATF but would think it would work.

[Ian Comerford]

Well it is an open bath and although the ones in this link Board Message are earlier ones the fact remains that the strut insert is not a sealed unit and the strut body holds the oil. I guess I will just fill it close to the top once I figure out what type and weight of oil to use. Anyone help with this?

Thank you

Ian

[Ian Comerford]

Thanks for this, useful advice. They do seem to be working fine, I've not had any issues with them but will consider new cartridge type inserts

Thanks again

Ian