Replacement ABS Control Units
#1
Replacement ABS Control Units
Hi all,
Looks like I have to replace the ABS control unit on my '90, 3.6 XJS as 3 of the solenoids are down plus possibly other issues once stripped down. This is the unit under the bonnet that combines electrics and hydraulics. Couple of questions:
LeeP
Looks like I have to replace the ABS control unit on my '90, 3.6 XJS as 3 of the solenoids are down plus possibly other issues once stripped down. This is the unit under the bonnet that combines electrics and hydraulics. Couple of questions:
- Does anyone know if you can pull out the electronic side of these units without disturbing the hydraulics?
- I know these are available new (at £££s!) but does anyone know of any specialists (not necessarily in the UK) who can rebuild these units? I believe they were originally made by ATE.
LeeP
#3
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leep123 (10-03-2015)
#4
Hi Lee
While it is quite possible to replace the 'Valve Block' while the unit is still in the Car, its really a whole lot easier to take the unit out first.
It is very easy to do in well under an hour.
You don't even need to remove the Air Cleaner unit, just remove the hinged lid and take out the filter.
Also don't even bother to take the Reservoir off, as this is very handy to hold onto when you jiggle the unit out of the Car.
Start by draining Brake fluid out of one of the Front wheels, to empty the Reservoir as much as you can.
You will have to bleed the low pressure side, when you put it back but as long as you know that, it won't be a problem.
The thing you have to watch out for, is Brake Fluid pouring out inside the engine compartment, as it is almost impossible to empty out the Reservoir Completely.
And whatever you do, don't get any drops on the Paintwork or it's 'Game Over'
I also put heavy duty Tin foil underneath the Actuator, to make a sort of Water Slide, so any escaping Brake Fluid would drip down underneath the Car to be caught in an old Washing Up bowl.
A bit like you see in Theme Parks but on a smaller scale.
Also stuff rag everywhere to catch any spills, and then pull out any Fluid soaked rag from underneath the Car.
The reason its much better to take the Unit out, is because you do not want to lose or damage the 'O' rings that go between the Valve Block and the Actuator.
Also when putting a New Valve Block back, you have to be REALLY CAREFUL! that the Valves don't fall out, under their own weight and break the delicate wiring that is inside.
So fragile you could break it just by looking at it, if you know what I mean.
And so it is much easier to reassemble the whole thing, while its sitting on your Kitchen Table.
You are going to need a New Gasket for the Pedal Box and one of the best things for this, it to cut a Gasket out from one of those smooth sided Brand New Hot Water Bottles.
Removing the Valve Block from the Master Cylinder/Actuator
Don't Lose or Damage these 'O' rings (replacements NLA) Only use Brake Fluid for lubricating them.
These Valves can drop out under their own weight, which will be certainly heavy enough to break the delicate Wiring, so when you re-assemble it be extremely careful and take your time.
Cut a New Pedal Box Gasket from a New Hot Water Bottle which is perfect for this job being 2.5mm
While it is quite possible to replace the 'Valve Block' while the unit is still in the Car, its really a whole lot easier to take the unit out first.
It is very easy to do in well under an hour.
You don't even need to remove the Air Cleaner unit, just remove the hinged lid and take out the filter.
Also don't even bother to take the Reservoir off, as this is very handy to hold onto when you jiggle the unit out of the Car.
Start by draining Brake fluid out of one of the Front wheels, to empty the Reservoir as much as you can.
You will have to bleed the low pressure side, when you put it back but as long as you know that, it won't be a problem.
The thing you have to watch out for, is Brake Fluid pouring out inside the engine compartment, as it is almost impossible to empty out the Reservoir Completely.
And whatever you do, don't get any drops on the Paintwork or it's 'Game Over'
I also put heavy duty Tin foil underneath the Actuator, to make a sort of Water Slide, so any escaping Brake Fluid would drip down underneath the Car to be caught in an old Washing Up bowl.
A bit like you see in Theme Parks but on a smaller scale.
Also stuff rag everywhere to catch any spills, and then pull out any Fluid soaked rag from underneath the Car.
The reason its much better to take the Unit out, is because you do not want to lose or damage the 'O' rings that go between the Valve Block and the Actuator.
Also when putting a New Valve Block back, you have to be REALLY CAREFUL! that the Valves don't fall out, under their own weight and break the delicate wiring that is inside.
So fragile you could break it just by looking at it, if you know what I mean.
And so it is much easier to reassemble the whole thing, while its sitting on your Kitchen Table.
You are going to need a New Gasket for the Pedal Box and one of the best things for this, it to cut a Gasket out from one of those smooth sided Brand New Hot Water Bottles.
Removing the Valve Block from the Master Cylinder/Actuator
Don't Lose or Damage these 'O' rings (replacements NLA) Only use Brake Fluid for lubricating them.
These Valves can drop out under their own weight, which will be certainly heavy enough to break the delicate Wiring, so when you re-assemble it be extremely careful and take your time.
Cut a New Pedal Box Gasket from a New Hot Water Bottle which is perfect for this job being 2.5mm
Last edited by orangeblossom; 10-03-2015 at 05:22 PM.
The following 4 users liked this post by orangeblossom:
#5
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leep123 (10-03-2015)
#6
#7
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orangeblossom (10-05-2015)