1996 Mercedes SL 600
Discussion
I have yet to phone the local dealer, but "genuineautoparts" indicates list price is £125 but they're offering 40% discount making them £75 each. I will check tomorrow, but if that is indeed the list price, and I never manage to get more than 10% off at the dealer (124 loom excepted when I got 15% off, probably through pity) it looks like mail order for me.
The new a/c condensor has been fitted, along with a new water pump, auxiliary belt and rear brake hoses. The front of the engine casing and the alternator were thoroughly degreased so the source of any fresh oil leaks should now be apparent. I think the timing case gaskets could do with renewal sooner rather than later and possibly the valve cover gaskets.
A new thermostat is on order. It's an easy fit, mounted right at the top front of the engine, in the V.
The bearing for the noisy secondary air pump was taken to a bearing specialist but they could not match the part. They have managed to quieten it down, so it's not quite so undignified during the cold start cycle. Another 600 owner told me it is possible to fit a shorter aux. belt and bypass the air pump altogether, without throwing a fault code, so that's a cheap option to consider down the line.
I have replaced the front and side indicators. The fog light lense I ordered was for the wrong side so I have ordered again.
A satisfying simple job for my young son was to fit a new o-ring to the oil dipstick. It now seals properly when pushed in.
The original Exquisit (Panasonic) head unit has been sent off for repair, to fix the leaky LCD and broken cassette flap. Parts are still available but have to be sent over from Yokohama in Japan and I am advised they are quite slow.
Next job is to renew the hydraulic fluid for the ADS suspension system and the folding roof. The current fluid looks like it hasn't been changed for an eternity so I have ordered Febi ZH-M 02615 and will post some pics of the fluid change in the ADS and hood reservoirs.
A new thermostat is on order. It's an easy fit, mounted right at the top front of the engine, in the V.
The bearing for the noisy secondary air pump was taken to a bearing specialist but they could not match the part. They have managed to quieten it down, so it's not quite so undignified during the cold start cycle. Another 600 owner told me it is possible to fit a shorter aux. belt and bypass the air pump altogether, without throwing a fault code, so that's a cheap option to consider down the line.
I have replaced the front and side indicators. The fog light lense I ordered was for the wrong side so I have ordered again.
A satisfying simple job for my young son was to fit a new o-ring to the oil dipstick. It now seals properly when pushed in.
The original Exquisit (Panasonic) head unit has been sent off for repair, to fix the leaky LCD and broken cassette flap. Parts are still available but have to be sent over from Yokohama in Japan and I am advised they are quite slow.
Next job is to renew the hydraulic fluid for the ADS suspension system and the folding roof. The current fluid looks like it hasn't been changed for an eternity so I have ordered Febi ZH-M 02615 and will post some pics of the fluid change in the ADS and hood reservoirs.
Edited by Hereward on Saturday 15th October 10:47
That's appreciated, thank you, but I should be all sorted when my unit is repaired. I think parts for the Becker units are harder to source than the Panasonic units.
I changed some of the hydraulic fluid from the ADS reservoir tonight. Not a full drain down, I would doubtless break something trying to loosen off the drain nut.
Siphoned about 1.3 litres out. The oil was filthy, it's possible it's never been changed.
Old oil on the left. The new stuff (Febi ZH-M 02615) looks like elderflower cordial, with a hint of yellow. Probably doesn't taste quite as good, though.
The filter is only 7 quid so I've ordered a couple of new ones. The gauze is filthy but also very delicate. The hydraulic return line is attached at the top left, on the threaded section.
I will change the power hood reservoir fluid at the weekend.
I changed some of the hydraulic fluid from the ADS reservoir tonight. Not a full drain down, I would doubtless break something trying to loosen off the drain nut.
Siphoned about 1.3 litres out. The oil was filthy, it's possible it's never been changed.
Old oil on the left. The new stuff (Febi ZH-M 02615) looks like elderflower cordial, with a hint of yellow. Probably doesn't taste quite as good, though.
The filter is only 7 quid so I've ordered a couple of new ones. The gauze is filthy but also very delicate. The hydraulic return line is attached at the top left, on the threaded section.
I will change the power hood reservoir fluid at the weekend.
Edited by Hereward on Tuesday 18th October 21:43
There are different Merc fluids. The Citroen L-HM is green, too.
I did the SLS in my 124 recently, a system which uses the same components and fluid as the 129's ADS, and the Merc fluid was clear yellow. It is made by Febi. Even the bottle is the same. It is very satisfying to change these things. As you say, it has probably never been done before. While the oil's function is primarily hydraulic rather than lubrication, clean oil must be a million times better for all the myriad seals and valves than the filthy dirty stuff which comes out. I did the power steering fluid and filter, too; this is another oil which never gets changed even though the job can be done for less than £25. I felt a slight difference in the steering as a result (although it could be all in the head).
I did the SLS in my 124 recently, a system which uses the same components and fluid as the 129's ADS, and the Merc fluid was clear yellow. It is made by Febi. Even the bottle is the same. It is very satisfying to change these things. As you say, it has probably never been done before. While the oil's function is primarily hydraulic rather than lubrication, clean oil must be a million times better for all the myriad seals and valves than the filthy dirty stuff which comes out. I did the power steering fluid and filter, too; this is another oil which never gets changed even though the job can be done for less than £25. I felt a slight difference in the steering as a result (although it could be all in the head).
I haven't got round to renewing the soft top's hydraulic fluid but I have replaced the thermostat.
The water was taking 20 mins to get up to temperature so clearly the coolant thermostat had failed in the open position.
A new Wahler thermostat was sourced, after initially being told I may have to wait 5 months for one!
It's a nice bit of kit. I tested it in a pan of water first. It's set to open at 87 degrees C and lo and behold it did.
The thermostat is about the only easy access part on the engine, nicely mounted at the top of the V at the front of the engine. I didn't even need to drain the coolant.
Upon inspection you can see the old unit was stuck open. I was impressed to see the date stamp of 08/96. It was the original, 20 year old part!
The water was taking 20 mins to get up to temperature so clearly the coolant thermostat had failed in the open position.
A new Wahler thermostat was sourced, after initially being told I may have to wait 5 months for one!
It's a nice bit of kit. I tested it in a pan of water first. It's set to open at 87 degrees C and lo and behold it did.
The thermostat is about the only easy access part on the engine, nicely mounted at the top of the V at the front of the engine. I didn't even need to drain the coolant.
Upon inspection you can see the old unit was stuck open. I was impressed to see the date stamp of 08/96. It was the original, 20 year old part!
I have been using the car occasionally over Winter on dry, salt-free days, cycling the hood and suspension hydraulics. I refreshed the hood reservoir fluid at the end of last year.
With the hood down I could hear an occasional clicking from the rear wheels so decided to strip down and inspect the rear brakes. I also purchased new backing plates, with the current items being heavily corroded after 20 years.
The rear brakes are fixed caliper with one pair of opposing pistons. The park brake is a shoe-in-drum type.
The calipers are the originals with plenty of surface corrosion so they would be cleaned up and chemically treated.
Stripping down the brakes is very simple, although having a ramp does make the job so much more civilised. Car in the air, wheel off then it’s easy to access the two 15mm bolts that hold the caliper in place. These came off without complaint and the caliper slid off the disc with no fuss. No need to bleed the system at all.
The disc is retained on the hub flange with a small hex screw and then the disc can be pulled off the hub to reveal the parking brake assembly.
I scraped off years of crud and used a can of brake cleaner spray on each side of the car to clean the backing plate, caliper and hub. To replace the backing plate would require removal of the hub and that was a job too far at this stage, so I cleaned up the existing backing plates and coated them with Hydrate 80. Despite the current ones looking rather shabby their renewal is a job for another day.
I fitted new Febi brake shoes and retaining springs and adjusted the disc biting point. The clicking noise was caused by the tip of the wheel bolts hitting the park brake mechanism. This was evident on both sides of the car, with minor impact damage to the components. Surprising because the wheels and bolts are OEM but the thread is simply a few mm too long for this application. I replaced the M12x1.5x40mm radius wheel bolts with 35mm bolts so they would clear the mechanism. 35mm is adequate; this gives 21mm of available thread of which 7mm is brake disc and 11mm is hub flange, leaving just 3mm of protruding thread, which is not enough to foul the park brake.
The current pads and discs are in good condition. I removed the pads from the calipers and regreased their backs. The pads can be replaced with the caliper bolted in position on the disc. The pad retaining pins and spring clips were heavily corroded so I fitted new ones. The calipers were cleaned then surface treated with Hydrate 80. There was no need to push back the pistons when refitting the pads and calipers over the disc.
A very satisfying job. I will do the fronts next. They look like fixed caliper four piston jobbies.
Up she goes:
Pad retainers and caliper looking shabby:
That's better:
With pads removed you can just make out the circular pistons that push the pad against the disc:
New parking brake shoes, with adjusting teeth:
Shorter (35mm thread) bolt clears the park brake mechanism. No more uncivilised clicking noises:
With the hood down I could hear an occasional clicking from the rear wheels so decided to strip down and inspect the rear brakes. I also purchased new backing plates, with the current items being heavily corroded after 20 years.
The rear brakes are fixed caliper with one pair of opposing pistons. The park brake is a shoe-in-drum type.
The calipers are the originals with plenty of surface corrosion so they would be cleaned up and chemically treated.
Stripping down the brakes is very simple, although having a ramp does make the job so much more civilised. Car in the air, wheel off then it’s easy to access the two 15mm bolts that hold the caliper in place. These came off without complaint and the caliper slid off the disc with no fuss. No need to bleed the system at all.
The disc is retained on the hub flange with a small hex screw and then the disc can be pulled off the hub to reveal the parking brake assembly.
I scraped off years of crud and used a can of brake cleaner spray on each side of the car to clean the backing plate, caliper and hub. To replace the backing plate would require removal of the hub and that was a job too far at this stage, so I cleaned up the existing backing plates and coated them with Hydrate 80. Despite the current ones looking rather shabby their renewal is a job for another day.
I fitted new Febi brake shoes and retaining springs and adjusted the disc biting point. The clicking noise was caused by the tip of the wheel bolts hitting the park brake mechanism. This was evident on both sides of the car, with minor impact damage to the components. Surprising because the wheels and bolts are OEM but the thread is simply a few mm too long for this application. I replaced the M12x1.5x40mm radius wheel bolts with 35mm bolts so they would clear the mechanism. 35mm is adequate; this gives 21mm of available thread of which 7mm is brake disc and 11mm is hub flange, leaving just 3mm of protruding thread, which is not enough to foul the park brake.
The current pads and discs are in good condition. I removed the pads from the calipers and regreased their backs. The pads can be replaced with the caliper bolted in position on the disc. The pad retaining pins and spring clips were heavily corroded so I fitted new ones. The calipers were cleaned then surface treated with Hydrate 80. There was no need to push back the pistons when refitting the pads and calipers over the disc.
A very satisfying job. I will do the fronts next. They look like fixed caliper four piston jobbies.
Up she goes:
Pad retainers and caliper looking shabby:
That's better:
With pads removed you can just make out the circular pistons that push the pad against the disc:
New parking brake shoes, with adjusting teeth:
Shorter (35mm thread) bolt clears the park brake mechanism. No more uncivilised clicking noises:
Looks good. The more I learn about the R129 the more I realise how rare and special the 600 is.
With the hood reservoir did you flush the system or just replace the reservoir contents? I've got two litres of Febi 02615 ready to go as that is now top of my to-do list.
Are you still looking for a panoramic roof? There was a silver one advertised in the Member Classifieds of the March edition of Mercedes Benz Club magazine for a reasonable sum (£750ish IIRC).
With the hood reservoir did you flush the system or just replace the reservoir contents? I've got two litres of Febi 02615 ready to go as that is now top of my to-do list.
Are you still looking for a panoramic roof? There was a silver one advertised in the Member Classifieds of the March edition of Mercedes Benz Club magazine for a reasonable sum (£750ish IIRC).
Zonergem said:
Looks good. The more I learn about the R129 the more I realise how rare and special the 600 is.
With the hood reservoir did you flush the system or just replace the reservoir contents? I've got two litres of Febi 02615 ready to go as that is now top of my to-do list.
Are you still looking for a panoramic roof? There was a silver one advertised in the Member Classifieds of the March edition of Mercedes Benz Club magazine for a reasonable sum (£750ish IIRC).
Objectively there is very little reason to choose the 600 over the 500. Subjectively it's worth it for the elevated dopamine and serotonin levels it produces in the driver.With the hood reservoir did you flush the system or just replace the reservoir contents? I've got two litres of Febi 02615 ready to go as that is now top of my to-do list.
Are you still looking for a panoramic roof? There was a silver one advertised in the Member Classifieds of the March edition of Mercedes Benz Club magazine for a reasonable sum (£750ish IIRC).
I didn't drain the hood hydraulics by the book (I think there's a system drain point somewhere?). I siphoned the reservoir, refilled it, cycled the hood a few times then siphoned and refilled again. The fluid seemed pretty clean anyway.
Ha, I saw that panny roof ad and thought about it. Decent price. However, my car is only used in the dry so I really don't need any form of hardtop at all at this stage. I do keep an eye on Ebay. If one comes up in the right (or nearly right) colour I may bite but currently it's an extravagance not a necessity.
I hope you're enjoying your car.
Hereward said:
Objectively there is very little reason to choose the 600 over the 500. Subjectively it's worth it for the elevated dopamine and serotonin levels it produces in the driver
Rare honesty, thankyou HerewardMy thoughts:
I've driven two 600's, one in SL form the other an S class, I found them fussy, orchestrally muddled, mechanically unrefined and not THAT much quicker than the sweet(er) V8
Love this thread though
cheddar said:
Hereward said:
Objectively there is very little reason to choose the 600 over the 500. Subjectively it's worth it for the elevated dopamine and serotonin levels it produces in the driver
Rare honesty, thankyou HerewardMy thoughts:
I've driven two 600's, one in SL form the other an S class, I found them fussy, orchestrally muddled, mechanically unrefined and not THAT much quicker than the sweet(er) V8
Love this thread though
However, just as the V8 owner probably regards his engine/car as superior to the V6, so the V12 owner feels the same. A V12 flagship car is a nice luxury to own. It's also cool to go to the Pagani website and see "Mercedes-Benz M120" stated as the Zonda powerplant. It's a special engine.
I find the V12 to be almost too refined. It is SILENT, even with the roof down. Above 4,000 rpm there is a distant turbine stirring itself. My son is hassling be to get it straight-piped so it sounds like this (go to 45 seconds in on this Youtube clip):
https://www.youtube.com/watch?v=uTklVFGYYZw
But that's not what this car is about for me. It's for wafting around on a sunny day thinking that, actually, life is okay.
Hereward said:
Objectively there is very little reason to choose the 600 over the 500. Subjectively it's worth it for the elevated dopamine and serotonin levels it produces in the driver.
[...]
I hope you're enjoying your car.
I have a serious endorphin deficit, caused by winter storage and not driving the car. Serves me right for buying at the end of October. But it is in good condition and summer isn't far off now. [...]
I hope you're enjoying your car.
Hereward said:
cheddar said:
Hereward said:
Objectively there is very little reason to choose the 600 over the 500. Subjectively it's worth it for the elevated dopamine and serotonin levels it produces in the driver
Rare honesty, thankyou HerewardMy thoughts:
I've driven two 600's, one in SL form the other an S class, I found them fussy, orchestrally muddled, mechanically unrefined and not THAT much quicker than the sweet(er) V8
Love this thread though
However, just as the V8 owner probably regards his engine/car as superior to the V6, so the V12 owner feels the same. A V12 flagship car is a nice luxury to own. It's also cool to go to the Pagani website and see "Mercedes-Benz M120" stated as the Zonda powerplant. It's a special engine.
I find the V12 to be almost too refined. It is SILENT, even with the roof down. Above 4,000 rpm there is a distant turbine stirring itself. My son is hassling be to get it straight-piped so it sounds like this (go to 45 seconds in on this Youtube clip):
https://www.youtube.com/watch?v=uTklVFGYYZw
But that's not what this car is about for me. It's for wafting around on a sunny day thinking that, actually, life is okay.
IanA2 said:
Only my opinion, but I think the SL60 in the pick of the range.
Ah, if we're talking about the special R129's (other than the run-of-the-mill 280/320/500/600) then it has to be the SL73. 12 cylinders are better than 8, right? 
http://jalopnik.com/5421459/sl73-amg-the-pagani-zo...
I'd love to see some pics of your SL60.
Hereward said:
IanA2 said:
Only my opinion, but I think the SL60 in the pick of the range.
Ah, if we're talking about the special R129's (other than the run-of-the-mill 280/320/500/600) then it has to be the SL73. 12 cylinders are better than 8, right? http://jalopnik.com/5421459/sl73-amg-the-pagani-zo...
I'd love to see some pics of your SL60.
https://www.flickr.com/photos/127882433@N08/153199... that were taken just before selling. Machine polished and gleaming. I had fun with the
registration, R60 HWA.
The rear callipers are standard ATE items and are available for about £120 each. I bought a pair from Amazon about two years ago.
I have only driven the V12 in a w140. I thought it was a superlative engine. I liked the refinement and the engine note when pressing on very hard; I thought there was a performance advantage, especially at very high speeds like over 90mph; and then there is the simple pleasure of having the V12.
I have only driven the V12 in a w140. I thought it was a superlative engine. I liked the refinement and the engine note when pressing on very hard; I thought there was a performance advantage, especially at very high speeds like over 90mph; and then there is the simple pleasure of having the V12.
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