[TenZero]

Backstory: I bought my 2004 S600 with 78k miles and failed ABC. Had it towed to my house, (had to use a special race car trailer because it sat too low for the flatbed wrecker. I paid $2700 for the car, which was a "can't lose" price; the seller was just done spending money on it, and the $3k estimate for fixing the ABC again just pushed him over the edge. Anyway, I got a nice low mileage car (not a creampuff) for silly money. My intention was to delete ABC and go to coilovers from the get go. After a less than pleasant experience with Strutmasters, I ended up with a set of Yellowspeeds in the car, which I'm very happy with. Since my ABC system was ruptured, I have simply been running the ABC side of the pump dry, which I've heard may or may not work.

I've been enjoying the car for the last 6k miles, until recently, when the power steering began complaining. It became hard to turn at low speeds, and making uncomfortable groaning noises. Info on this forum indicated that the ABC pumps do not last long running dry, but a popular conversion for V8 cars was to swap power steering pumps from an air ride car. Unfortunately for me, it seems no one has done this on a V12 yet. User Cowboyt is running coilovers on his V12 with a fluid recirc to a regular ABC pump.

I like the idea of running the V8 PS only pump on my V12 car, but there are some obstacles, which as far as I know, nobody has solved yet. So I got busy trying. First, I bought a used PS only pump off of an S500, with the idea getting both pumps in my hands to compare them and see if it is worth doing. Comparing pictures was very promising! Then, I removed the tandem pump from my V12, (and you know what a pain that is) and got them on the bench together. Well, there are some obstacles!

1) The pulleys don't match. V12s have a 7 rib belt, V8s have a 6 rib belt.
1.5) Pulleys are not interchangeable
2) The mounting holes are the same pattern, but there is a lot of space to make up just to get the V8 pump to match the V12 belt line.
3) The rear mount is different.
4) The power steering line output is in a different position. Big problem!
5) The V8 pump mounted fluid reservoir interferes with the V12 coilpack.

Photo shows my V12 tandem pump (top) and a V8 PS pump (bottom) with the mounting tabs roughly aligned. Offset is significant.

http://www.benzworld.org/forums/attachment.php?attachmentid=2186489&thumb=1

So, my ideas were that I would need to custom fab something(s) to make this work. But What?
1) Spacers/mounts/bracket to match M275 beltline (not too bad, if you get the measurements right the first time)
2) Custom 7 rib pulley to match beltline (LOTS of machine time =$$)
3) Custom PS output line (Again, not too bad)
4) Rerout reservoir supply to OEM remote tank. (Easy)
5) Custom PS fluid reservoir
6) Convert V12 to 6 rib belt to match PS pump with off the shelf Ford part (Easy!)

If none of this works, I will buy a reman ABC pump, and fab a fluid recirc system like Cowboys

Project in progress, updates as they occur!

 

[TenZero]

Update! Measurements taken, everything checked twice, and latheing up some spacers for the correct standoff. This should get the V8 pump pulley into the correct beltline on the V12. There is 1.375" (35mm) standoff difference between the pumps, measuring from the inside edge of the pulley on both. I've made 4 spacers total. From the front of the motor, the lower left mount needs a 1.375"x .750" spacer. The upper right mount has a separate hanger bracket, so needs a spacer on each side of the hanger with a total stack height of 1.375". The stock rear mount does not align with the V8 pump, but there is an unused hole on the V12 that does line up with a mounting hole on the V8 pump, so that is what I used, also with a 1.375"x .750" spacer. I have also measured and sourced for new mounting bolts. I need 2 X M8x70mm in front, and 1 M8x60mm for the rear.

 

[mercy-me]

Excellent solution to the spacing issue! I would have made them myself in my old machine shop days! However unless I have missed something, what will you do for the belt groove miss match? I think that you could possibly use the same machine shop source to simply remove the grooves from the S500 PS pulley and use it that way. Hopefully there would still be enough grab to drive the pump when parking or other pressure sensitive maneuvers were needed requiring full pump pressure assistance. "Necessity is the mother of invention!" Good job!


Bob

 

[TenZero]

Update: V8 pump mounted

After getting all the measurements sorted, and making the spacers, it's time to test fit everything. The spacers are made from steel bar stock, so I coated them in orange primer to prevent corrosion. This also makes the spacers easy to identify and visualize in the pictures, in case I didn't describe them well enough. Now that they are fitted up, everything is spaced and aligned perfectly to the belt drive line of all the other accessory pulleys on the V12. I'm really happy with how this is turning out so far. From the front, you can see the 1.375"x.750" spacer on the left, and the two spacers and the stock hanger bracket on the upper right. In the second pic, you can see the rear mount with the other 1.375"x.750" spacer in the unused mount position. The rear mounting bolt threads straight into an available 2nd mount on the back of the V8 pump. Below that, you can see the stock rear mount position on the bracket, which does NOT align with the other rear mount on the pump (just to the left). They are off by about 3/4", and it would have been a much more complex spacer to make.

 

[TenZero]

Update: 6 rib pulley solution

After getting all the spacers sorted out and ensuring the 6 rib V8 pulley is correctly aligned with the inside 6 ribs on all the 7 rib pulleys on the V12, here is my solution to the 6 rib/7 rib problem that everyone seems to be getting hung up on.

Firstly, machining a custom 7 rib pulley is a LOT of work (Time=$$) for a qualified machinist, especially if it is a one off project that he can't continue to make money on to spread his costs. There are probably 3-4 hours total in just getting my spacers right. Unless you have the tooling to do it yourself, you would be looking at paying for at least a dozen hours of time to get it right. This would eat all the cost incentive to use a V8 pump in the first place. As far as I could tell, no one has done the work and sells a part like this.

What someone DOES sell, and it is in stock at Autozone, is a 6 rib belt in the correct length. Dayco part #5060923, for $35.99. By aligning my V8 pump with the inside 6 ribs on all the other pulleys, I can just run the car on a 6 rib serpentine belt, and call it done. The 7th rib, (closest to the radiator) will remain unused. There is no reason why this shouldn't work, as long as a premium quality belt is used. I would expect slightly shorter life expectancy, since the 6 rib is about 0.1" narrower than the 7 rib. Rib spacing, depth, and cut are all the same standard. I got it all installed, and the belt length is the same (the pulleys are the same diameter, just different ribs). Just crank on the tensioner, and slip it on, just like a standard belt.

 

[Dave2302]

Hi,

Nice work buddy, you are a true hot rodder / modder, like me :grin

Cheers Dave

 

[cowboyt]

This, too, is a fine solution. Well done, TenZero.

I was considering doing something similar, actually. The reason I went with a reman pump is twofold. First, I don't have machining equipment (maybe someday). Second, the reman pump was $250 at the local auto parts store, after turning in my CORE. The fabrication for the new line was $150, so for $400 and some labour time, I had my solution. I suppose you could do it with washers as spacers, but that's kinda ugly.

Were I to do it again, I might well also choose TenZero's solution, since he was kind enough to share his measurements. Either way is a good way to go.

 

[TenZero]

Update: PS hard line

I've had to take a few days off from this project, because life happened. Everything has gone really well so far, but now I've gotten to the stickiest part of the conversion. Now that the V8 pump is successfully mounted, and the belt installed, the last real obstacle is that the power steering supply line to the rack is too short to make it to the pump output. As you can see in the pics, the output port on the pump (large gold hex on the left) is about 4" farther forward from the port on the old tandem pump. The hard steel line is about 4" short of being able to connect, and there is nowhere near enough flex in the line to make up the distance. Looking from the front, there is also about a 30 degree difference in clock position, or about 1.5" of vertical I need to make up as well.

Since the fittings on each end are Mercedes specific, I want to keep them original for simplicity. My plan is to remove the line from the car, and then have my local hydraulic shop add 4" of flexible extension near the top, right before the 90 degree bend that goes into the pump. that should give me the necessary length, and the flex line will allow for a little fine tuning of the fit in case the measurements aren't exact. The other simpler option would be to just braze in a section of hard tubing in the correct length. I will defer to their expertise on the best way to solve this of course. Removal of the line looks to be the hardest part; and once this is done, The rest is easy, just plumbing a reservoir and return lines, filling ,bleeding, checking for leaks, etc.

 

[Dave2302]

Hi,

Yeah, Hydraulic Hose Shop would be the route I'd go :wink

Good work, nice write ups and pics :smile

Cheers Dave

 

[wallyp]

Be nice if the new line uses the connectors that can be tightened on installation - makes it a lot easier to get the angles right.

 

[TenZero]

Update: Plugs and gaskets

I've done some of the "while you're in there" jobs. To get to the Tandem pump and get enough access to everything to do this conversion, the driver's side coilpack, intercooler and intercooler hardline needed to come out. I noticed the valve cover gasket shows weeping, and I was not certain of the age or condition of the plugs. The car had 78k on it when I got it (about 85k now), and the previous owner claimed he had all the plugs changed when on of the coilpacks was replaced at the dealer. With all the other klugey bullshite mistakes the dealer 'mechanics' have done on this car, I just decided to change all the plugs anyway. That way, I KNOW they've been done. So, off with the coilpack and intercooler hardware on the passenger side as well. Really only about 10-15 minutes extra work.

On my car, (13 years old, 85k miles), the valve cover gaskets were toast. They were so crispy, they crumbled into little pieces when I pulled the covers. The spark plug valleys had quite a bit of oil in some of them, so I hosed them all out with carb cleaner and compressed air *before* removing the plugs, to keep oil and dirt from draining into the cylinders. On removing all the plugs, I found 3 different brands and ages/condition in my car, so my decision to change them all was a good one. 24 new Denso Iridium Power IK20's went in, along with the 2 new gaskets. Also good to have the chance to clean all the oil and gunk from the coils, to keep them functioning properly and hopefully extend their lifespan.

 

[TenZero]

Be nice if the new line uses the connectors that can be tightened on installation - makes it a lot easier to get the angles right.

The hydraulic shop I finally located were great guys! Nobody local to me would do it, so I ended up over 100 miles away. Totally worth the drive though. These guys made improvements to my design request based on the cell phone pics I showed them, and built my line while I waited. I'm excited to get it fitted up, I think it's going to fit perfectly. And yes, they built it with connections that can be clocked and tightened during assembly.

 

[Dave2302]

On removing all the plugs, I found 3 different brands and ages/condition in my car, so my decision to change them all was a good one. 24 new Denso Iridium Power IK20's went in, along with the 2 new gaskets. Also good to have the chance to clean all the oil and gunk from the coils, to keep them functioning properly and hopefully extend their lifespan.

Hi,

:frown

I see this kind of FRAUD, (and that's what it is), all the time in UK :crying
These @rses have Charged the Labour and Parts, and the Customer has been DEFRAUDED :|

This is exactly why I say "Fit New Plugs" to new owners, who haven't personally watched 16 or 24 plugs going into their Engine.

There should be some simple, cheap, Legal Process of permanently closing down these "Mechanics / Garages" who do this sort of thing, it is one of my 'pet hates' :frown

Cheers Dave

 

[TenZero]

Hi,

:frown

I see this kind of FRAUD, (and that's what it is), all the time in UK :crying
These @rses have Charged the Labour and Parts, and the Customer has been DEFRAUDED :|

This is exactly why I say "Fit New Plugs" to new owners, who haven't personally watched 16 or 24 plugs going into their Engine.

There should be some simple, cheap, Legal Process of permanently closing down these "Mechanics / Garages" who do this sort of thing, it is one of my 'pet hates' :frown

Cheers Dave

Dave, you're absolutely right, it is fraud. But? My biggest problem with this is that it's not "Mechanics/Garages" or some crap independent shop. It's the MB dealership! Every mistake, missing bolt, stripped thread, unchanged sparkplugs, loose hose clamps and brackets, every single kluge I've found on my car has a corresponding receipt from the dealership for the work involved, clearly connecting the dealer to the abysmal level of workmanship. People who don't know better (like my previous owner) are paying $150/hr for work that wouldn't pass muster at Jiffy Lube. In their minds, they are paying premium rates for mechanics who don't make mistakes, and that's not what they are getting. I can imagine that the S600's poor reputation for reliability and poor ownership experiences comes in part from mechanics who take zero pride in their work. I would've hoped MB would run a tighter ship than that.

Good for me though, I got a beautiful car for 2% of MSRP.

 

[Dave2302]

Dave, you're absolutely right, it is fraud. But? My biggest problem with this is that it's not "Mechanics/Garages" or some crap independent shop. It's the MB dealership! Every mistake, missing bolt, stripped thread, unchanged sparkplugs, loose hose clamps and brackets, every single kluge I've found on my car has a corresponding receipt from the dealership for the work involved, clearly connecting the dealer to the abysmal level of workmanship. People who don't know better (like my previous owner) are paying $150/hr for work that wouldn't pass muster at Jiffy Lube. In their minds, they are paying premium rates for mechanics who don't make mistakes, and that's not what they are getting. I can imagine that the S600's poor reputation for reliability and poor ownership experiences comes in part from mechanics who take zero pride in their work. I would've hoped MB would run a tighter ship than that.

Good for me though, I got a beautiful car for 2% of MSRP.

Hi,

Well, yeah it always seems to be the "Main Dealers" that are the worst, see this in my workshop over and over

Have you photographed all these things ?

I'd be contacting MB USA and seeing what they are prepared to do, such as a lifetime 30% discount on parts for you :wink

This is why a good Indie is worth his weight in gold :wink

And yeah, couldn't agree more, I now have 3 MB on my personal fleet, all reliable, with no faults, everything working as it should, and all were purchased for a tiny fraction of their resale value :grin

All I want now is to find a cheap SL55 for £3k that "no - one can fix" :big laugh:

Cheers Dave

 

[TenZero]

Update: PS line install

So here is my solution to the power steering hard line mismatch. You can see in the photo that I needed to make up about 4 inches between the end of the hard line and the pump output. The hard line has numerous bends and angles in it that carefully route around the turbo and exhaust plumbing, so you can't just pull it up to close the distance. Luckily, I found that there is a joint in the line where the hard line can be separated. This means that I didn't have to remove the whole supply line to the rack (a huge job). The fitting is on the drivers side, just at the end of the heat shield jacket. Using a a nice 3/4" piece of plywood under the oilpan, I jacked the engine up about 2" or so, and removed the hardline. It has to be finagled out, and there is a bracket holding it to the motor that has be removed (1 bolt) but it comes out the top. By the way, there is no room at all to be able to use a flex line to replace this. Hydraulic hose with the correct ID for the fluid flow is just too fat to fit and make the intricate bends the hard line does.

The end closest to the pump has a 90 deg bend where it enters the pump. Basically, I cut the 90 corner out, and was left with about a 1" piece with the Mercedes fitting that screws into the pump, and about 2" of straight line on the end before the next bend. The hydraulic shop brazed a 90 deg fitting to the 1" piece, and a straight fitting on the end of the hard line. In between, they made a 3" piece of hose with corresponding fittings on each end. Since we were operating off of cell phone pics, and weren't exactly sure about the length, they also added extension fittings so I could make it a little longer. (These weren't needed, it fit perfectly) The fittings are loose, so everything can be rotated and clocked just right during install. I finagled the hardline back in, then I plugged the new line into the pump, bent the flex into position on the hardline, and then tightened everything up.

My power steering pump is off an air ride S500, and it came with a pump mounted reservoir. (Bought on Ebay for 90 bucks) On the V12, the S500 reservoir can't be used because the left coilpack is in the way. I had hoped to be able to ditch the giant ABC tank, but I reinstalled it to use the original PS reservoir. I will probably go back and get rid of the ABC tank later. I then found that the supply hose from the V12 reservoir is bent the wrong way to match up to the pump and not interfere with the pulley. After I stared at it for a while, I took the hose off the tank, reversed it, installed it backwards, and it fits perfectly with plenty of clearance for the pulley. Now, all the custom stuff is done, and it's ready for reassembly and shakedown testing. I really think this is going to work!

 

[TenZero]

Update: Done!

Once the power steering hardline and fluid supply hose were attached, reassembly was otherwise normal. Since I aligned my pump spacers to the inside edge of the pulley on both pumps, I made sure to align the 6 rib belt leaving the rib closest to the radiator unused on all the other accessory pulleys.

After reassembly, I filled the PS reservoir to the top with Pentosin CHF11S, and jacked the front wheels off the ground before starting the engine. Immediately after engine start, I turned the wheel full left and full right and then shut the engine off. After this job, there will be a substantial amount of air in the PS system that must be bled. This needs to be done with no load on the wheels to avoid pump cavitation. After shutoff, I found the reservoir to be nearly empty again, so I refilled it once more. After this first time, it should monitored, but you won't likely suck any air. If you do suck air, you need to do it all over again.

After waiting awhile for air bubbles to settle out of the system, (A couple of hours, and this won't happen while the pump is running) I lowered the car and started her up. Everything works perfectly, just as it should. I've driven it about 200 miles before writing this up, just in case I screwed something up, or the idea didn't work out. From the driver's seat, you would never be able to tell any difference. The power steering functions exactly like it did when running the old tandem pump, the ratios and variable assist seem spot on. There are no odd noises, and the 6 rib belt drives the AC and charging system (the two highest load accessories) with no complaints. In short, it's a custom install that does not have any idiosyncracies or minor niggles to explain away. It works just as intended, and you'd never know unless you needed to replace a belt or something down the road. Result!

Since I've already done all the engineering work, this is actually not too difficult a mod to accomplish on your own V12 if you want to.

What you need:
1) Power steering pump off an air ride V8 car S430/500 (I got a pump off a 2001 S500, I don't know for sure if there are any variations in model years)
I recommend getting a used pump from Ebay or something. You will need the mounting bracket and pulley. New pumps I looked at didn't come with these pieces. My Ebay pump came with everything. Cost: $90 shipped

2) Custom fabricated hydraulic hose modification to original hardline. Cost: $65 + a 12 pack of beer for the shop. Use my pics so they know what you're talking about.

3) 4 spacers, machined from bar stock. I used steel, aluminum would work too, I guess. They are all .750" diameter, and two of them are 1.375" long. The two smaller ones are different thicknesses from each other. I'll edit this later when I find where I wrote the dimensions. All these are gun drilled with a .325" hole down the center to fit an 8mm bolt. You'll also need your version of my good friend Joe with a lathe to make these for you.

4) 3 new mounting bolts, 2x M8x70mm, and 1 M8x60mm, and a couple a washers. About $5 at Lowe's
(The metric hardware selection at Lowe's is way better than Home Depot)

5) Dayco belt part #5060923, about $35, in stock at Autozone.

With the spacers already made and in your hands, you can swap the pumps out fairly quickly. Getting the tandem pump out is the worst part of that job. The most time consuming part is extracting the hardline and having the custom line fabricated. Once you get that back in, easy.

Total cost: About $200, all in.

 

[dunnbros]

Great write up and it gives me the courage to attempt it myself.
So you did this writeup about a year ago, how is the mod working a year out? Any updates for someone who is thinking about doing this mod?

The Tandem pump went bad in my 2001 S600 with a coil over modification. I've already removed the old pump and I'm deciding to either go with your solution of a S500 air ride PS pump or to replace the tandem pump and create a bypass hose to circulate the ABC side without routing through the entire ABC system (pump output to cooling side of ABC system).

I prefer your solution but I have a question. Do you know or have an opinion on if all the measurements and modified hoses are the same on a 2001 S600? Or do you think there are differences I'd have to discover on my own?

I'm also curious if you left the old ABC components (Valve blocks, lines/hoses, etc) in the car, or did you remove them?

Thanks in advance
Bill
2001 S600

 

[cowboyt]

Anyone heard from or been able to contact TenZero? I sent him a PM about the dimensions for those spacers he talked about.

 

[Dave2302]

Hi T,

Not heard from him in a while now.

If you read post #17 it has all the dimensions, well apart from a thickness difference which shouldn't be too hard to figure when doing the Job :devil

Yeah, Yeah, I know, I've done worse too :wink

Cheers Dave