Abc valve block??

[karozza]

The front seems to be diving around a centimeter over night & stays there as for as long as it's parked. Does this mean a dirty valve block?? Is this at a dangerous stage as I have a long weekend drive to Sicily this coming weekend??

I think it's been doing this for quite some time. But, as I have recently replaced the ABC fluid & fitted lowering links have been studying this more.

Once driving about during the day, all is well. No warning or irregularities on start up either.

 

[grober]

http://www.mbclub.co.uk/forums/amg-lounge/156674-removing-abc-rear-valve-block-w220.html

 

[karozza]

Thanks Grober but that's the rear valve block, although, the principle is this the same!?

My real query is, can it wait as I have a 600-1000Km driving holiday coming up this weekend?

I don't really like to take these things apart just a few days I have to travel as if anything drastic happens, I won't have time to get parts etc!

 

[BlackC55]

Is it leaking?

 

[karozza]

Is it leaking?

No.

 

[BlackC55]

It may not be a valve block issue.

I would get it on a Star and test the pump.

 

[karozza]

Normally wherever I read about the car sinking when left parked, it's always the valve block that comes up!? Apparently, the valve leaks back to the reservoir...in most cases, it needs to be cleaned to solve the issue.

 

[zoros]

Hi Karozza.

First things first - if it's not leaking and it rectifies itself once the engine starts - it's fine and it can wait (indefinitely).
I have (had) the same issue and found that the "level sensor" was the culprit.
This is one of two identical sender units which sits about 6" inboard of each of the rear wheel assemblies on top of the rear axle. You can see it plain as day (each side) when looking in this area when you get down on your knees.
The sensor consists of two main components: the electronic sender unit (box) and the linkages (which are a two part plastic arm (much like your arm coupled by the elbow)).
The electronic box is £65 plus vat and the separate linkage is £12 plus vat from the mai dealer.
My linkage on the nearside had broken in half and was sending duff info to the ABC black box and the ABC was reacting to this.

Secondly if you recycle the ride height button after starting the car - a number of times (rodeo) this helps in keeping the system circulating fully.

Enjoy your trip and don't worry about it (provided you DON't have a leak!!!).

 

[karozza]

Hi Karozza. First things first - if it's not leaking and it rectifies itself once the engine starts - it's fine and it can wait (indefinitely). I have (had) the same issue and found that the "level sensor" was the culprit. This is one of two identical sender units which sits about 6" inboard of each of the rear wheel assemblies on top of the rear axle. You can see it plain as day (each side) when looking in this area when you get down on your knees. The sensor consists of two main components: the electronic sender unit (box) and the linkages (which are a two part plastic arm (much like your arm coupled by the elbow)). The electronic box is £65 plus vat and the separate linkage is £12 plus vat from the mai dealer. My linkage on the nearside had broken in half and was sending duff info to the ABC black box and the ABC was reacting to this. Secondly if you recycle the ride height button after starting the car - a number of times (rodeo) this helps in keeping the system circulating fully. Enjoy your trip and don't worry about it (provided you DON't have a leak!!!).

Thanks Zoros.

My issue is with the front sagging similarly on both sides slightly. I have just recently fitted new lowering links & so no problems in that area.

Will give the valve block a good clean when I get back.

 

[karozza]

Has anyone actually cleaned or repaired a front valve block on here??

 

[v8dve]

The front block as far as I know is exactly the same as the rear one

 

[m2287]

Has anyone actually cleaned or repaired a front valve block on here??

Me!

 

[karozza]

Me!

Were you successful by cleaning; did you replace the O ringsi??

 

[m2287]

Were you successful by cleaning; did you replace the O ringsi??

I was successful yes, didn't change the orings I don't think (it was a while ago now)... It didn't solve the problems had (which was very different to yours and turned out to be a faulty level sensor) but it did have dirt in it and the seal/orings around the solenoids were knackered, I used some sealant to reseal them... Haven't had any problems since touch wood.

 

[kevinharper]

Hi Yes I have refurbished 3x ABC valves both front and rear. I have spent 3 years researching and I have sourced the Oring set in high quality HNBR. I refurbished a front valve this week - all 4 solenoid valves and works perfectly. I have extra sets of the Orings. For people who care you only really need change the 2 o rings inside the smaller check valve solenoids. But its easy to change the full set once you strip out the valve. If you want the o rings message me.

 

[kevinharper]

The block and solenoids are exactly the same but the hydraulic accumulator is smaller with a different bracket.

 

[kevinharper]

be very careful driving when the valves are not working. High pressure will get back to the pump when you drive over a bump in the road. It will be ok for a few days but eventually the high pressure will blow a hole through the dual hydraulic pump seals !!! An £800+ replacement. The valves can be refurbished for cheap price. The O ring set plus 2 or 3 litres pentosin CHF11S. Takes about 2 hours to get the valve block off refurbish and put it back in place.

 

[kevinharper]

Hi the problem is surely with the two smaller solenoids on the valve block. These are the stop check valves. The other two larger solenoids are self adjusting when car is in motion.
You need replace the two O rings inside each of the two stop check valves so per valve you need two 14 dia and 2 16 dia very special O rings. The dia I show are not the exact dia as they are very special. Took me 3 years to obtain them. For the other 2 solenoids you need 2x 12 dia, 2 x 13dia, 2 x16 dia and 4x 19 dia. (all per valve block.

 

[Borys]

I did same procedure on my cl500
Got o rings from local hydraulic shop. There were very tight to put on but fingers crossed two weeks in and no problem

 

[Mr Kripling]

I thought the check valves that stop the car dropping when the engine is off are metal-to-metal valves. Surely changing the o-rings isn't going to affect a droopy car?