ASC+T Unit Leaking

[pollack138]

My ASC+T unit is leaking but as anyone who has dealt with these knows they are very hard to see let alone remove/replace. Wondering if anyone knows if they are prone to leaking in a specific spot (i.e. O rings or cracked housing etc.) and if there is any possibility of replacing seals or rebuilding the unit. If not does anyone know where to source a used one?

[dragon850]

They are not super prone to leaking but do occasionally. Removal is not super hard but yeah a bit of a pain.
I have 1 good used pump available.
Pm me if interested.

My ASC+T unit is leaking but as anyone who has dealt with these knows they are very hard to see let alone remove/replace. Wondering if anyone knows if they are prone to leaking in a specific spot (i.e. O rings or cracked housing etc.) and if there is any possibility of replacing seals or rebuilding the unit. If not does anyone know where to source a used one?

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[pollack138]

Follow up on ASC+T rebuild (leaking and code 18-leak defect plunger accumulator). Thanks for your reply dragon850, I waited until after I did a rebuild attempt before looking for a used replacement. The leak I had was on the brake fluid side and after disassembly found the 2 pistons and bores filled with corrosion/sludge. The bores were corroded with small pits but the seals were not torn. At this stage it is really replacement time but because of the situation I was in I had to have my car mobile by the next day so I ended up trying a temporary repair. I cleaned out the sludge and used 600 grit sandpaper then 2000 grit to clean the bores by hand. After lubing the seals with silicone grease I reinstalled everything and to my surprise there are no leaks. Hopefully this will buy me some time so that I can source a cheap used one locally. As a side note my code 18 that has been plaguing me for years seems to be fixed. I have cleaned and replaced both asc filters on numerous occassions and sometimes it will fix the light but only for a short time. I have had the light out now for 3 days and many start/stop cycles which is far longer than ever before. I will update if the light comes back on.

[Timm]

Great work, a repair that costs next to nothing and just needs a bit of elbow grease and emery cloth is a winner!

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[Fatandre]

What is it that gets damaged?

[pollack138]

On mine it was caused by corrosion in the plungers of the brake fluid section (there are also 2 Pentosin power steering controlled plungers that mechanically push the brake hydraulic side plungers). The corrosion is most likely from the original owner not changing the brake fluid often enough. I've had the intermittent ASC light/code 18 problem since day one but it didn't start leaking till recently. I have driven it quite a bit more since my last post and still no light so I'm starting to feel confident this has been my problem all along

[Fatandre]

I only get the ASC light and just bought another ASC T unit. We will see if that fixes it.

[pollack138]

did you get a code?

[Thh850]

Does any one have advice on how to disasemble the ASC+T unit on a 91 850i ? Have difficulties to figure out how to detach the part where the break fluid plungers are from the rest of the asc+t unit.
I'm new here, located in Finland, and trying to get a -91 850i back on the road after 9 years in the garage. But have a brake fluid leak from the ASC+t unit.

[vr117]

I have a e32 and I’m having the same issue can someone detail this repair can it be done on the car on my 1994 740 I it looks like a hassle to remove any advice will be appreciated