603 with head mounted sls pump - PeachParts Mercedes-Benz Forum

martureo · #1 01-04-2016, 01:59 PM

I know that that the 603 found in 124 wagons and in w140 sd models had a dual power steering/sls pump at least within the US. I've seen a few examples of a non-turbo 603 having the older style (read: s123/617) pump bolted to the head. Does anyone know if the head is any different?

Is there a way to mount the sls pump to a 603 head instead of using the dual pump?

The main reason I'm asking is I'm trying to plan out the engine bay of a 603 in a s123, and keeping the SLS system operational. The SLS reservior on the s123 (except for '85) appears to be only on the passenger's side while the 603 in the 87 s124 configuration has the dual pump and SLS reservoir on the driver's side. I'd like to know if I can keep things on the passenger's side (who knows where) or if I'm forced to route the high pressure line/low pressure return across the engine bay.

Examples

(yes I know this is a 602)

vstech · #2 01-04-2016, 09:09 PM

Gotta be a special head and pump I'd guess.

I recommend just routing the hoses across the motor.

sixto · #3 01-05-2016, 12:13 AM

The parts list might be extensive - head, sprocket with pump drive, maybe a different valve cover and gasket... I'd plan for a tandem pump unless you have a line on parts not available in US models.

Sixto
83 300SD

martureo · #4 01-05-2016, 08:40 AM

I got this reply from another forum. Very helpful.

Quote:

Hi!

n/a engines always have a cam-driven hydraulic pump. The valve cover is different, as is the valve cover gasket. The difference is that the cam-drive covers have a sem-circle cutout to allow the flange on which the pump is mounted to be instalkled & sealed.

However, there is one obstacle: that is the cooling fan. On the W124 chassis with this cam driven pump it's VERY tight to install the cooling fan & cowling. On the 603 Turbo it's impossible. The 603 Turbo has a bigger metal fan which needs to be installed together with the cowling & fan clutch - it would be impossible with the SLS pump mounted on the head. And there might even be clearance issues with the fan, I've not tried it.

Though fabricating some hydraulic lines should not be that big of a problem?? They'r metric and can be joined with ermeto couplings, I've done the same when re-routing the SLS reservoir on my 124 Coupé (needed space for Turbo air filter housing).

^you can just about see the shaft runing from the cam gear which required the cut-out in the cylinder head. If I was you, I'd see if you can get away with removing/installing (and runing) the big Turbo cooling fan without pulling the radiator and then go from there... But I'd keep the big fan. Hell, what do I care? If you can live with pulling the radiator to remove the fan for changing a belt or something - do whatever floats your boat Smile

In short: you need
- a different valve cover,
- the jack-shaft runing from the cam gear,
- a "floating" coupler to connect pump & shaft
- and the pump flange to install the SLS pump on the cylinder head.
- And a different cam gear bolt (allen hex)

babymog · #5 01-05-2016, 08:47 AM

I know that the 602 & 603 n/a head castings are not the same as the turbo castings (according to the FSM), not sure if this is part of the differences or not.