Remove/install piston rings

AR03.10-W-7311B

3.8.11

ENGINE 541.9 in MODELS 950, 952, 953, 954

ENGINE 542.9 in MODELS 950, 952, 954

W03.10-1058-06

1 Piston ring (keystone ring)

2 Piston ring (taper-faced ring with inside angle)

3 Piston ring (bevel-edged ring with spring expander)

3.1 Coil spring

4 Pistons

5  Pliers

5.1  Knurled screw

A Spread value (piston ring)

Arrow Coil spring end gap

Modification notes

6.2.06

Measure piston ring end clearance - added.

Step 7

	Removing
1	Remove piston (4)		AR03.10-W-7021B
2	Remove combustion residues on piston rings (1, 2, 3)
3	Clamp connecting rod and piston (4) in a vise	 Use protective jaws for clamping.
4	Adjust to max. permissible spread value (B) at pliers (5) knurled screw (5.1)		*BE03.10-N-1002-05D
			*000589373700
5	Remove piston rings (1, 2, 3) in order from top to bottom		*000589373700
	Checking
6	Check piston rings (1, 2, 3) for chippings on coating	 All piston rings (1, 2, 3) on the piston effected must be replaced if there is damage.
7	Measure piston ring gap clearance of piston rings (1, 2, 3)		AR03.10-W-7311-02G
			*BE03.10-N-1001-05D
		Feeler gauge
	Install
8	Adjust to max. permissible spread value (B) at pliers (5) knurled screw (5.1)		*BE03.10-N-1002-05D
			*000589373700
9	Insert piston ring (3) spring expander (3.1) into lower groove on piston (4)
10	Install piston ring (3) with pliers (5)	 The coil spring end gap (arrow) must be installed offset by about 180° to the piston ring end gap.
			*000589373700
11	Install piston rings (1, 2) in the sequence from below to above using pliers (5)	 Pay attention to installation position. Marking "TOP" must point toward piston crown.
			*000589373700
12	Check piston rings (1, 2, 3) for chippings on coating	 All piston rings (1, 2, 3) on the respective piston must be replaced if there is damage.
13	Install piston (4)		AR03.10-W-7021B

Check values for piston rings

Number	Designation				Engines 541.9, 542.9 up to engine end no. 111419	Engine 541.9, 542.9 as of engine end no. 111420


BE03.10-N-1001-05D	Piston ring gap clearance	Groove I Keystone ring	When new	mm	0.60...0.75	0.45...0.60
			wear limit	mm	1.0	1.0
		Groove II Taper faced compression ring with inner chamfer	When new	mm	0.40...0.55	0.40...0.55
			wear limit	mm	1.0	1.0
		Groove III Double beveled oil control ring with coil spring	When new	mm	0.30...0.45	0.40...0.55
			wear limit	mm	0,8	0,8
BE03.10-N-1002-05D	Spread value of piston ring		max.	mm	43	43

000 589 37 37 00

Pliers