AHC failure component question and techstream questions. (1 Viewer)

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Hi new to the forum
Short introduction of what is going on, jump to the questions section if there is to much to read :)

I bought a 2008 200 series 4.5 v8 diesel with the AHC system at the moment it has around 387.000km on the odometer.

Issue
4 months into ownership a leak is present on the AHC system. Started as a few drops at the rear right wheel to to the point it was a pressurized stream whenever the pump started (ran it 3 times - once when the it burst and didn-t see it and 2 times to reposition the car on the drive way because my brain had forgotten to turn ths system off...)
Unsure if the issue can be weather related but at the time of it occcuring (back in late february) it was around -15C snow and ice. second time the car was moved was during warmer weather +-0C

Symptom
The leak is what looks like form the (pressure release?) valve on the pump since only the pump tray/bracket is wet not the pipe out from the pump. while inspecting the system it was found that the bleed screw on the front right control actuator has snapped.
I know i need to but have not had the popssibility to scan the car for codes yet ( i am ashamed to say)

Actions
Since the car and system is coming to its age (fluid change has been performed as per invoices with the car during it livetime)
I have a new pump and globes and oil to replace.

Questions
Can the AHC system be bleed via the rear or does every corner need to be bleed by it self?
Is it advisable to buy (a) new actuators? what is the part number?
What is the size and thread of the bleed screw? (to replace the others and incase i can save the actuator.
The short (first) pipe is corroded in the pump - best way to remove it?
Is it advisable to ad a new pipe section in the system? if so what is the pipe size and flare? Can a copper pipe be used? or Better buy a new pipe from toyota?
Is the Techstream needed for the configuration of the new components?
Is it needed when bleeding the system after all the components have been replaced? from the videos online it seems pretty straight forward but there the car is not in a fault state.
Techstream and AHC - is the OBD2-mini VCI cable enough or is the bigger box (VXdiag?) required? (will get one for other things regardless.)

I do work in the automotive field so the work is not a problem just want to know and have the knowledge of the system so it is done correctly.

I have been trying to find these question through out the forum and found a lot of help but did not stumble upon the exact answers i am after.
Would appreciate some help or guidence in the right directions.
 
The main issue is the pump isn’t self priming. So if it runs dry it tends to burn out. And new pumps some times take some work to prime.

Have several 2.5l cans of fluid available.

For bleed screw you can likely get it off a parts diagram.

Techstream is useful as you can force a system test. If you keep the pump wet and just plug and play, you can likely get by without it. Having access is better, particularly if you run into some issues.

If you have the tooling to shape/flare the pipe ends, you can use whatever. AHC is mineral oil based.

I’d focus on finding your leak as step one. If it’s the reservoir pump assembly just swap it out.

Bleeding is just like a brake system. Pressurize, open a bleed, run the bubbles out, move to the next corner.
 
The main issue is the pump isn’t self priming. So if it runs dry it tends to burn out. And new pumps some times take some work to prime.

Have several 2.5l cans of fluid available.

For bleed screw you can likely get it off a parts diagram.

Techstream is useful as you can force a system test. If you keep the pump wet and just plug and play, you can likely get by without it. Having access is better, particularly if you run into some issues.

If you have the tooling to shape/flare the pipe ends, you can use whatever. AHC is mineral oil based.

I’d focus on finding your leak as step one. If it’s the reservoir pump assembly just swap it out.

Bleeding is just like a brake system. Pressurize, open a bleed, run the bubbles out, move to the next corner.

Just to add it depends on the line and which end. Some of them are huge banjo-style fittings.
 
Thanks. for the helpful advise.

Do you have any advise on how to keep the pump primed or a thread on the forum? I have not managed to find one.
I have 5L at home bought from Toyota

The pipe is a normal threaded fitting

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