How to change Plug Bleeder on AHC System?

[HDJ80fan]

Hy there,

Is it possible to change the plug bleeder (49189-60010) on the 4 actuators and 1 accumulator?

Problem: My plug bleeders are very rusted and I need to change them. I am affraid that they wont last for the next bleedings...

Anyone done this in the past?

 

[2001LC]

If you can turn them to bleed, they'll come right out. It's a very good idea to change if rusted. Often times the rubber bleeder cap is missing and they'll rust inside the bleeder passage then snap off when turned. This is also true of brake bleeders.

Good idea to soak with penetrating oil before attempting to turn rusty bleeders.

 

[HDJ80fan]

I'm just afraid that it will loose too much fluid! The presure is very high and I'm not sure if I can screw the new one in before too much fluid is running out. Is it possible that air will come in the system when too much fluid is out? That would be worst case I guess...

Have you changed them yourself? Does it work without problems?

 

[2001LC]

I've not changed the AHC bleeders but have done brake, a bleeders a bleeder. I would suggest you use the bleeding procedure and change one by one at end/bottom of each ones bleed (hope that makes senses)
AHC Fluid Change How To -- Need Input

 

[ITRJ]

Make sure the engine is off. Use a jack stand to support the weight of the vehicle. Unscrew old bleeder. Screw in new bleeder. Bleed air from system after repairs as per the "flush AHC system thread that's on this forum.

 

[HDJ80fan]

I've not changed the AHC bleeders but have done brake, a bleeders a bleeder.

Well, the presure on the AHC is way higher! I know how to change a bleeder. No problem.

In the "How to" is written "6oz at the time". Changing the bleeder will defentitly drain way more than 6oz. So I'm worried about air in the system.

That's why I'm asking if anyone has done it.

 

[ITRJ]

The high pressure in the system when the engine is off is caused by the weight of the vehicle on the suspension. If you jack up the vehicle and let the wheel hang, there shouldn't be much pressure in the system and you can replace the bleeder.

 

[PADDO]

Well, the presure on the AHC is way higher! I know how to change a bleeder. No problem.

In the "How to" is written "6oz at the time". Changing the bleeder will defentitly drain way more than 6oz. So I'm worried about air in the system.

That's why I'm asking if anyone has done it.

Yes I have changed bleeders, and accumulators, and shocks. The recommendation to raise the vehicle is good advice as it relieves the static pressure due to the hydraulics supporting the vehicle's sprung weight but you'll still have residual pressure, about 2MPa at each corner, due to the damper accumulators' charge, but at a low fluid volume. The height accumulator has about 6MPa gas pressure behind it and about 9.5MPa when charged. Jack the front wheels off the ground, safely support to your satisfaction, crack a front bleeder and you'll loose a small amount of fluid, same as changing globes, and replace the bleeder. You will have none to minimal air entry if just unscrew and fit the new bleeder. Do the other front side. Same process for the rear. The height accumulator will expel about 300ml from a full charge when you crack its bleeder. If you don't support the vehicle when changing out the bleeder then you'll bleed off about 1litre total from L when the vehicle drops to the bump stops, significantly less if the front and rear are supported so the volumes within each shock actuator aren't expelled. Replace the drained fluid volume, or at a minimum ensure your reservoir fluid level is well above MIN with the system at N and engine idling. Turn off the engine and do a quick bleed crack at each corner to expel any air, you might get a bubble or two at most. HTH.