ABC BLEEDING
I have read so many threads about bleeding the system and not one has mentioned if you remove the dipstick when bleeding the system. Basically my question is if you do not remove the dipstick how does the air escape?
The reason why I ask is because I picked up an 2003 S55 AMG and I can hear air in the steering aspect of the ABC being it is a tandem pump. In regular power steering systems you remove the dipstick and turn the steering wheel lock to lock to remove the air. I am tempted to do this in this scenario, but I know if the pump sucks in air it will basically self destruct.
If I remove the power steering dipstick with the engine on and turn the steering wheel lock to lock will this remove air from the system or cause the ABC pump to suck in air?
Thanks.
Last edited by taleb659; Sep 9, 2013 at 02:11 AM.
taleb659 says:
The question that has been bothering me is when you do the rodeo how does the air escape?
I know the rodeo and dynamic pitch are two ways of letting the air escape.
I have never seen in any WIS manual that calls for the dipstick to be removed.
When doing the rodeo so the air can escape, can you elaborate how the air escapes without removing the dipstick?
Michael Warfield says:
There is an airgap between the top of the reservoir and fluid level. I know its not vented to the outside but there is no pressure build up in the reservoir because the fluid displaces the space that the air bubble would normally take up. Its not like a can of soda where the carbon dioxide is disolved in the liquid using pressure.
The air bubbles come to the top of the reservoir because its the highest point, but for every bubble, the fluid drops down to replace the lost space.
Sometimes it takes a long time for the air to get out of the system.
a few days... up to a week.
taleb659 says:
So your saying when the rodeo is done, they leave the cap on and the air just sits at the top?
Michael Warfield says:
Yes, all the air will come to the top. I have replaced many pumps and struts and this is all that is needed
taleb659 says:
That makes sense why they never mention to either leave the dipstick on or remove it.
Michael Warfield says:
You will get a noise when turning the wheel when a power steering or ABC line is touching the frame.
taleb659- says:
will it hurt if the rodeo is done and the dipstick is removed?
Michael Warfield says:
It sounds just like a power steering whine. No it won't hurt it
I spoke with a tech a couple days ago at my local dealer and they have used mityvac to purge the air from the steering aspect of the ABC system successfully. Hence where I got the idea from.
If you end up being right and it does not work then at least i have a nice mityvac for different occasions
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I have a video of it on my phone, will try and get it onto YouTube or something so you can see it for yourselves, but the fluid was being pushed out of the sides of the head of the dipstick (makes more sense when you watch the video).
I never knew these holes were even there
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