alas

Greetings, I have a 2005 R230 with under 69k miles which I bought about 9 years ago. Thank you for this forum as it has helped me tremendously with several DIY tasks. Throughout my years of ownership, I replaced the front valve block (updated versions from Ebay) as the front was sagging and I put in a new Corteco accumulator at the same time. I also replaced the pulsation dampener and the pressure line connecting to it as I noted the line was "Sweating". Most recently, I noted the right rear seemed to sag a little so I replaced the rear valve block (Again with an updated version that I bought used from Ebay); however, I did not replace the 2 accumulators. A few weeks ago, I took her out on a long drive visiting friends here and there, and upon returning home, a large pool of fluid ended up on the driveway after I stopped the car; popped the hood and saw the fluid had spilled out of the reservoir. The reservoir wasn't completely depleted and I immediately refilled it. It did the same again with the fluid spilling out of the reservoir when I started the car up, and then the white message appeared. I tried cycling the ride height to no avail and then the red warning message came on. I refilled the fluid, waited a couple of minutes, restarted the car and was surprised too see no warning message on the dash. I read in the forum the symptom may be caused by a failed accumulator. So I thought perhaps the rear accumulators may be the culprit as they were replaced. My question is, how do I tell if the accumulator is really the cause? I went ahead and replaced both accumulators but when I used a plastic ziptie and inserted it into the accumulators, the depth of insertion checked out similarly. I have just drained the reservoir and the fluid appeared very dirty; this was a bit surprising to me as the system was somewhat "Flushed" using the return line disconnect method less than a thousand miles ago. I will be flushing the system a bit later but hope to seek inputs from fellow experienced members. Thank you.

cdk4219

Sounds like an accumulator, I flushed mine with 3 gallons or so over 15,000 miles and it always came out smelling burned and dirty, this is a car that has 52,000 miles on it. It’s a very weak system at best, with most all of the components going bad by 100,000 miles and pumps at 70,000 or so.

Switching my airmatic and hydraulic cars to riding on steel was a win all around for me. I don’t have the patience for the sort of things you are having to deal with. Plenty of other things in these cars that need attention.

alas

Thanks for the input. Latest disappointing update: prior to the flush job, I decided to fill the reservoir and let the system "Run" with a new filter installed, since the rear of the car is now sagging after I removed the rear valve block to replace the 2 accumulators. I started the car and the rear suspension didn't rise, and the red warning message appeared. I activated the ABC ride switch and no response. I then jacked the rear end up just a tiny bit and noted the warning message turned white but once I lowered the jack, the red warning came back on. I checked the reservoir for fluid level through the fill hole and I immediately noted there was no fluid movement. Could this be a sign the pump has failed?

g0rsq

Did you bleed the pump by pressurising the fluid reservoir first?

You need about 1 bar air pressure to force the fluid into the pump to prime it.

Tom Manning

Usually pumps leak first, or make a pretty obvious clackity-clack audible from the pulsation dampener area, on ABC 1 cars. Are there any fluid leaks coming from the pump?

If you have a basic scanner you can read the pump pressure. The Foxwell will do this.

If the front raises and lowers then I wonder if you got all the four connectors in the rear valve block connected back correctly?

Fluid gushing out the reservoir is a sure sign of a failed accumulator.

alas

Thanks Tom for the response. I have double checked the solenoids and am certain they are connected correctly (Wire bundles and solenoid bodies each have colored tape affixed). I also have rigged up a pump using the radiator cap tester and put 14 to 15psi precharge in the reservoir to no avail. The RED ABC warning remains and the rear just would not come up with the ride height switch activated. I did not notice shortly after the engine has shut down, the reservoir pressure increases to past 18psi and to avoid damage to the tank, I pulled the air line out.

alas

Thank you for the info. I put about 14psi precharge in the reservoir, and noted it drops to about 7psi seconds after engine start but it does not go down to zero. And after engine shut down, the pressure increases to past 17psi so i pull the air line out to avoid damage to the reservoir. There is no signs of leakage anywhere under the car, but I am hearing a slight whining noise when I rev the engine up. Could it be my rear valve block or potential pump going out? The front of the car still holds nicely but the ride switch won't do anything to either make it go up or down. The rear remains bottomed out.

alas

So I'm wondering, before I proceed with the accumulators replacement on the rear valve block, I had the left rear jacked up only and then I crack the bleeder screw open to release residual pressure (Only a very minimum amount of fluid came out) then I closed the bleeder after. I cracked it a second time to check and nothing came out. Could I have done the pressure release process incorrectly thus eventually lead to the predicament I'm having now, with the rear sagging and not coming up? Just thinking back to try and figure out what I may have done incorrectly.

Tom Manning

I was talking about the pressure the pump puts out, not the pressure in the tank. You need a scan tool to test the pump.

With the car jacked up, wheels off the ground and the engine off, the blocking valves close so there is no pressure in the struts.

The whining sounds sounds like the pulsation dampener is shot; that's what happens when they blow but that is not causing your woes. Does the front raise and lower?

I don't think it's really possible but are you sure you connected all the lines correctly at the valve block end? If the front goes up and down then the pump is working. I'd be checking all the lines at the rear, and maybe put the old valve block back in to test it and see what happens. The red warning indicates a definite fault and you need to get armed with a scan tool at some stage to know more.

Check all those lines first, I have read of others mixing them up.

alas

Tom, the front end remains steady and does not go up or down using the ride switch. I'll recheck the connections tomorrow and borrow a knockoff SDS from a friend to see if there are codes to be read. Thanks again for the info.

Tom Manning

I'm wondering if you primed it properly, but you said you did. Now I'm thinking the suction restrictor valve on the pump could be malfunctioning. This controls fluid ingress into the pump. You can check for 5 Volts on the valve.

An easy DIY to prime the pump is a foot pump for bikes and toys. Just slip a 1" piece of clear hose over the end of the Schrader valve connection then the other end over the dipstick hole You don't need much pressure; just enough to make the tank bulge a bit.

As pumps age they can need regular priming.

If neither axle will raise then you have pump issues, but it's strange that it doesn't work at all, they can be right down on pressure but still raise the car promptly. The back end is probably all OK, with no pump pressure it's not going anywhere now though.

MikeJ65

The regulating valve is a pilot operating valve. You need about 100 bar for it to start regulating. If the pump doesn't produce enough volume, you can have flow but not build any pressure. When you shut off the car, pressure bleeds through an orifice, draining the accumulators. Once pressure drops to about 100 bar, the regulator drops out and the pressure quickly drops to zero. With good accumulators, the gradual drop will be about 30 seconds. You can do the pressure test on shutdown in DAS or other scanners to see this happening and evaluate the health of your accumulators.

I like to prime with an air nozzle sealed with a rag. Just start giving it puffs of air sufficient to bulge the tank a bit. You can usually tell when it 'kicks in'. A blown accumulator can cause it to lose prime, so keep trying to prime it. However, one symptom of a pump going bad is loss of prime and difficulty of repriming, so that is a possibility. The ABC valves will not be activated until pressure is achieved. If your blocking valves are good, the car will remain locked in position. It sounds like you have some leakage on the rear and that is why it is low, while the front is staying up on with good valves.

Aussiesuede

Simple trick that pretty consistently provides enough pressure for initial priming of the pump is to blow up a rubber party balloon, snap it over the fill reservoir, and squeeze it whilst you start the car. Works every time for me.

alas

My gratitude to all of you for your inputs. I ran the SDS and was relieved the pump was OK; it was putting out about 191 bar. The faults I saw relate mostly to Y36/2y2. Tom M, thank you for your advice about rechecking the connections to the rear valve block. I recalled when I re-connected the solenoids after replacing the accumulators, I didn't get that "Click" feel when I hooked up the BLUE solenoid. I took the assembly out today and looked at the BLUE solenoid and sure enough, one of the tiny pins was slightly bent resulting in a bad connection. I straightened that pin and carefully inserted all of the connectors and had my fingers crossed when I started her up; first thing I notice was no RED warning message, and then as soon as I put it in drive, the rear came up and everything seems to work fine now. Thanks to all again! Next on the agenda is to perform the rodeo and flush the entire system.

Tom Manning

Good work! Those little pins are delicate.

That's one of the blocking valves. Looking at the schematic, with the blocking valve stuck shut (no connector) and the control valve open, there's no flow to the strut, so either the pressure sensor or height sensors report to the ECU which controls the regulating valve and shuts off the fluid flow.