taleb659

I am familiar with the bleeding procedures for ABC systems by lowering and raising the car 15 to 20 times and using SDS to do the rodeo or dynamic pitch. My question is where does the air escape from?

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.

taleb659

Well since nobody answered I asked a master tech in the UK, and the dialogue between goes as follows:

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

w0ss

I thought the ABC system was vented via a little pin hole?

taleb659

That would make sense also, I really would like to dedicate this thread to bleeding the ABC system. Do you have any pic?

Thanks.

taleb659

I just ordered this mityvac kit. I plan on making sure there is no air in my system, and I know this kit will make sure of that. This is the link if anybody else is interested:

jnash

the mityvac wont get the air out. Air will be trapped within the hoses and valves of the system if there is any. Just drive it as it self bleeds. Make sure you level is at the lower mark on the dip stick with a cold engine. The proper way to replace and bleed at the same time is to use the Rodeo feature with SDS (Star diagnostics) and have the return line that normally is in the cap drain into a large bucket while continuing to pour fresh fluid into the reservoir making sure you never run it dry. You will need about 14 cans of it.

taleb659

I know the mityvac will not help the the suspension aspect of the system. I have an SDS, and have replaced a few pumps and rodeo is the best method for purging the air. This problem is quite different; I can hear air in the steering aspect of the ABC system.

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 .

jnash

Im sorry, I assumed you meant the ABC suspension side and not the power steering side of the ABC pump. You can do it the easy way and suck out the fluid in the steering reservoir with your mityvac or chicken baster, fill, and repeat until the fluid comes out clean after a few full lock turns. It's not that much fluid. I love my Mityvac and wish I had bought one years ago. Enjoy it!

w4sim

It is . . . . . as i found out to my shock horror when i cleaned the rear valve block out and then had to try and take the air out of the system.

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

taleb659

I am happy to report the mityvac purged all the air in the steering side of the ABC. I also confirmed w4sim hole on the dipstick. There are two small pinholes at the top of the dipstick that allow the air to escape. That is why Mercedes never called for the dipstick to be removed when performing the rodeo.

w4sim

Lets see if this works. If it does, you can see the fluid coming out in 2 opposite directions from the top of the dipstick.

joyski

i was reading your post and i am having issues bleeding the power steering pump side on 2003 cl 55 amg how would you use this tool since there is the return hose on top of cap and do i need o purchase the power steering adapter for the mytivac thanks