Lock-down re-furbishing

[paultv]

Spent a bit of time refurbing a few parts - rebuilt the ABS unit - the one in the car has an issue with fluid blockage on the front left side which causes the ABS to
not always engage when needed on that wheel - basically it will lock up. Also bleeding it is almost impossible - you need huge pressure to get a piddle of fluid out the nipple
( calliper is new ).

I've built a new throttle body out of differently sourced bits - the body itself is NOS - so the spindle sleeves are in good shape - the one on the car is floppy and lets a bit of air in.

Injectors are the cars original set I've had on the shelf for a year since their return from Injectortune - time to re fit them!

Can't help myself with the flashes of red paint!

TB_INJ_ABS.jpg

Paul

[BristolE30]

Looks good Paul!

How often have you refurbed your ABS unit? I doubt mine has ever been serviced... don’t notice anything but nor do I know how to test it

[paultv]

This is my first rebuild ever - it's been going on a while - as I bought a used unit to work on as my car is in daily use.

If you look at my ABS purge blog in the tech section - its also here:

https://bmwe30cabriolet-wdm.blogspot.co ... r-abs.html

there's some shots of the internal filters and you can see how clogged up they get.

I started this when I hit the brakes on a side road in Devon - cow shit everywhere and it was wet - ABS engaged but
not on the front left wheel which locked up. The system on the car reports no errors in normal use, so I decided to dry
test the car on a road with gravel on the verges. Putting one wheel in the gravel and hitting the brakes should engage
the ABS on that wheel as it approaches lock up. Well, the right one did and the left one would mostly just skid - although on occasion it would work.

I also found it really hard to bleed the front left, by this I mean it needs a LOT of pressure to pass fluid ... the right in normal, as is the rear... there is no imbalance in the braking response - it stops in a straight line...but I'm not happy driving with this ABS "fault".

I made a kind of test bed with brake pipes and syringes to push fluid through each gallery to test the fluid flow - after stripping cleaning and rebuilding the unit it passes
fluid with ease from the front and rear inputs to the outputs.

I have no idea where to get spares from, so you have to be careful about not damaging the filters - all the O rings can be replaced -

The first test of a second hand unit is that the solenoid work - failure is really rare - same with the pump motor - I've seen broken bus-bar connections under the relays mind you - so buying a donor
unit is a bit touch and go - I think I paid 50 quid for mine and it was pretty clean.

So when I install the new unit it will be interesting to open up the old one and see where the problem is ... I'll post some shots when I get round to it.

Paul