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Bought another 500SEL full hydro

Started by s class, 28 September 2015, 06:08 AM

s class

Next I fitted the new fan clutch, and it was better, but the car still battled chronically with cooling issues.  Admittedly, without a fan shroud the fan is farting against thunder. 

The cooling issues combined with the absence of brakes meant that I parked the car up on stands for the forseeable future, until the most pressing issues can be addressed.

First big order to MB South Africa :

- rear brake discs
- rear brake pads
- rear brake flex hoses
- front brake flex hoses
- new sump
- sump gasket
- oil pump pickup boot
- oil pressure sender unit


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

Got hold of the correct 6.5Jx14 rims (was sitting on 6.0J when I got it) :



With the internal fins for brake cooling :



[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

So over Christmas/New Year, I used my time to work on personal projects.

The rims came back from machining, and have now gone for stripping and coating .

As much as I want to drive this car, I have to accept that it will be some time before I get it in a driveable condition. At present I'm focussing on the serious problems.

a) cooling - car is totally unable to cope with traffic, no ability to control temp at all
b) oil pressure - the engine has oil pressure problems which worry me a bit  :neutral:
c) hydraulic suspension - the system is full of filthy engine oil, which is urgent to flush out before it wrecks the seals in the struts and valves
d) no front brakes..... not fun at all.


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

The plan of attack is :

a) cooling -
- new visco fan clutch (done)
- new thermostat (done)
- new shroud (old one was totally absent)
- ultrasonic flush radiator (done)

b) oil pressure
- new oil pressure sender unit (the gauge was a bit flakey)
- new sump to replace the bashed in original
- new pickup boot on base of oil pump
- after that, we will just have to see what happens.....

c) suspension
- root cause is the knobbed pump which is sucking in engine oil into the system
- replace front accumulators (done)
- replace filters (now done)
- flush system - this involves removing all 4 hydro struts so its a big job
- flush reservoir
- rinse and repeat x2, so to say

d) brakes
- new brake master (done)
- new front brake flex hoses
- skim front discs (due to shudder)
- rebuild front calipers
- at this stage I strongly suspect a failure inside the ABS pump itself, which is not good news... will have to see after the new master, hoses and calipers.


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

new fan shroud :

[

hose from reservoir to radiator... how does one do such poor repairs - its not like a new hose is expensive. 





So after seeing this all, I again said 'fekkit' and ordered ALL new hoses, and a new plastic reservoir tank.

The thermostat was indeed rooted.  Someone had drilled holes in it, which always indicates an attempt to work around a problem.  Tested it in a pot on the stove (I'm single, I can do these things).  Its an 84 degree unit, started to lazily open at about 93.  Again FFS, its only a few bucks for a new one, just replace it instead of drilling holes.


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

So, in the delay while waiting for hoses, I figured I'd look at oil pressure :

Genuine new sender of revised design next to original :



The new sump is here, sorry havent taken photos of that whole saga yet.


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

Starting to remove suspension pump for rebuild.  Bleeding off rancid fluid.  Its supposed to be clear...



back at home, starting to strip the pump.  (yes, the car is stranded at my dayjob offices, much to the amusement of colleagues)


Top cover off, revealing crankshaft and radial pistons :



Crank out, pistons clearly visible :



[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

pistons out



MOst difficult task is removing the steel cylinder block from the alloy housing.  The housing has to be heated (quite a bit).  Blue flame of the torch visible in the photo above.  Photo below shows cylinder block out.




Aaaannnnd, there we see the reason for all the curry - hamfisted previous effort to seal the pump with silicone (lots of it).  The shit is everywhere, blocking the orifices in the pump's reaction band, into the main pressure regulator.  This hydraulic stuff is PRECISION machined for metal-metal clearances.  Sealant shouldn't come anywhere NEAR this stuff


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

pump inverted to remove rear seal. 



Fully stripped pump :



reservoir removed, pressure regulator and valving also removed for overhaul :



Yes, its bleeding suspension fluid :-/



[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

Thought I'd have a quick check of the steering fluid.  Its also pitch black, and the spring that retains the filter is missing, so the filter has been doing eff-all.  No wonder the steering box is worn - but thats another problem for another day. 



[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

After many weeks of only working on other guys' stuff, I gave this project another push. 

Still in the stages of disassembly, some way off until any reassembly happens...

High priority has been the non-existent front brakes.  I decided to look at the front calipers.  They are not exactly fresh.  Some of the worst condition calipers I've yet seen. 



The brake hoses weren't much better :



Then there's also the matter of the front brake shudder.  So I got ready to remove the discs. 



Discovered that the front wheel bearings are absolutely rancid.


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

Started stripping all the subcomponents for rebuild :



Stripping the discs off the hubs :



Hub cleaned up with new bearing cones pressed in :



[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

Next of course the suspension bushes and balljoints basicaly disintegrated and came out in pieces :



[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

As a distraction from this, I removed the bashed up engine sump, and found (as expected) that the oil pump pickup boot was crushed hard against the oil pump, explaining the engine oil starvation problems :



Nice new pickup boot installed :



ANd then reassembled with a brand new sump and sump plug.  Nice.


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

I then started investigating the lacklustre engine performance.  I strongly suspected a shagged timing chain, and sure enough :

with the right hand cam timed on OT :



The crank damper showed 17 degress ATDC :



The limit of safety allowed by MB for this engine is 12 degrees of retardation.  17 is almost enough for valves to hit pistons, and certainly enough to exceed the capabilities of the chain tensioner, and result in poor engine performance. 

Seems I caught this one JUST in time. 

Starting to wind through the new chain :



Next weekend I'll finish the chain job with new sprockets, guides and tensioner.


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL