Machining the valve seats - ra05006010291x(0291)

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

Engines 601, 602 (except 602.98), 603

Preliminary work:

Cylinder head removed (01-415).

Valve springs removed (05-250).

Valves removed.

Valve guides checked (05-285).

Operation no. of operation texts and work units or standard texts and flat rates 05-4511

Fig 1: Machining Valve Seats

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Valve guides	check (05-285).
Valve seats	machine according to tool manufacturer's operating instructions. See data sheet for settings.
Valve seat	check for leakage (item 3).
Valves	insert and measure dimension "a".

DATA

Valve seat	Intake	Exhaust
Valve seat width (b)	1.2-1.7	1.7-2.0
Valve seat angle (α)	45°	45°
Upper correction angle (β)	15°	15°
Bottom correction angle (Y)	65°	65°
Permissible deviation in concentricity of valve seat	0.03	0.03
Min. dimension (a) on new valves and valve seats	0.1-0.5	0.1-0.5
Dimension (a) on remachined valve seats and reground valves	- 1.0	- 1.0

Fig 2: Identifying Valve Seats Dimension

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Dimension (a) is reduced by the amount the cylinder head face is ground down (see RI 01-418).

Fig 3: Identifying Valve Seats Dimension

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

COMMERCIALLY AVAILABLE TOOLS AND TEST EQUIPMENT¹⁾

Designation	e.g. company	Order no.
Valve seat turning tool with hand drive	Serdi GmbH Bregenzer Str. 69 88131 Lindau	SL 1050
Holding device for cylinder head and valve seat turning device	Serdi GmbH Bregenzer Str. 69 88131 Lindau
e.g.
Wall support or		SL 1100
work place or		SL 1200
machining center		SL 1300
Forming cutter for	Serdi GmbH Bregenzer Str. 69 88131 Lindau
Intake valve seat		41 191
Exhaust valve seat		41 192
Vacuum tester for leakage check	Serdi GmbH Bregenzer Str. 69 88131 Lindau	8000
Motorization	Serdi GmbH Bregenzer Str. 69 88131 Lindau	SCL 660
¹⁾ Other approved valve seat turning equipment and accessories are listed in the catalog "Test Reports for Test Benches and Equipment for Mercedes-Benz Workshops", Volume 1.

NOTE: With the machining tools listed under commercially available tools the various angles on the valve seat are machined in one operation. Clamp cylinder head in clamping device to disassemble and machine. Machine valve seats with valve seat turning device, with valve seat grinder or valve seat mill.

After machining the valve seat inserts check the installation position of the hydraulic valve clearance compensating elements and correct, if required (05-211).

It is also necessary to check the distance between the end of the valve stem and base of the camshaft bearing (01-418).

Check valve guide, replace, if required (05-285).
Machine valve seats (see tool manufacturer's operating instructions).
Insert valves and check leakage of valve seat with vacuum tester.

Fig 4: Checking Leakage Of Valve Seat With Vacuum Tester
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Insert valves and measure distance (a).
If dimension (a) is not within tolerance, replace valve seat insert (05-290).

Fig 5: Checking Valve Seat Surface
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.