richardpope50

My rear brakes are binding and have traced the fault to (what appears to be) the main ABS Actuation unit not fully returning after pressing the pedal to brake.

Ie. I brake and then the brakes bind - they turn but are stiff and not free as they should be. If I release a bleed nipple a minute amount of fluid comes out but frees the brake; or if I pull the activation shaft back a very, very small amount (and that's all it can move anyway) it frees the brake - I'm really just putting pressure on this shaft. Also if I leave it for some time, the brakes are freed presumably because the pressure in the unit fades away.

Does anyone know of anyone who can refurbish or in any way repair this main unit? Or give me any suggestion as to stripping down the unit and how to repair it. It's a Teves Mk2 unit.

Note, if I drive with the slightly binding brakes the disc, pads, etc, heat up and bind more eventually slowing the car down so it needs to be sorted.

Otherwise all seems to be working well and no dash lights on.

Really appreciate any help or pointers whatsoever.

Sierrasideways

iTrader: (1)

Could this help? Recent thread on here.

https://passionford.com/forum/restor...lock-info.html

Philip.

richardpope50

Thanks Philip. Interesting thread but there are four parts to the whole ABS system ..

1. The main actuator part that activates the brakes (when pedal pressed).
2. The pump unit with accumulator that pumps up the pressure to some 2,000psi
3. The valve block that will pulsate the brakes when wheel slip is detected.
4. The ECU.

Unfortunately it is 1.) where I am sure I have the problem.

Sierrasideways

iTrader: (1)

Hopefully someone on here can help you with it

richardpope50

It now appears to be the Teves Mk 4 where the valve block is separate from the master unit as fitted to later Sierras and Granadas.

If anyone has a used one, then I would be interested - PM me.

Caddyshack

I sold the valve block but have 2 accumulators and 2 masters if you need bits.