Remove/Install Valve Springs And/Or Valve Stem Seals - AR05.30-P-3500MRA

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Engine 274.9 in model 205

Engine 274.9 in model 253

MODIFICATION NOTES

05.08.2019

Information document AH05.30-P-1000-02SZ, added.

Operation step 13.

Courtesy of MERCEDES-BENZ USA

Fig 1: Valve Springs/Valve Stem Seals Components Location - Engine 274.9 In Model 253

Courtesy of MERCEDES-BENZ USA

	Risk of injury to skin and eyes due to handling of engine oil. Risk of poisoning caused by swallowing engine oil	Wear protective gloves, protective clothing and safety glasses. Do not fill engine oil into beverage containers.	AS18.00-Z-0001-01A
	Risk of injury caused by scraping or cutting body parts on sharp vehicle parts	Always wear protective gloves when working on or near sharp and non-deburred vehicle parts. Deburr repair panels.	AS00.00-Z-0017-01A
	Notes on avoiding damage through contamination and foreign objects		AH00.00-P-5000-01A
	Remove/install
1	Remove cylinder head (1).		AR01.30-P-5800MRB
2	Remove valve clearance compensating elements.		AR05.00-P-2011MRA
3	Mount cylinder head (1) onto assembly device (01).	Before commissioning ensure that the counterholder (02) for the assembly device (01) is mounted correctly on the cylinder head (1). Otherwise, the cylinder head (1) will be damaged. Follow the operating instructions for the assembly device manufacturer (01). Assembly tool	Fig 2
4	Attach assembly lever (03) with depressor (04) to sliding piece (05), place depressor (04) vertically on top valve spring retainer (2), and align sliding piece (05).	Depressor	Fig 7
		Valve assembly tools kit	Fig 4
5	Move air suspension bellows of the assembly device (01) with a lever (06) until they stand centrally over the combustion chamber of the respective valves (6).	Ensure that spring bellows for assembly device (01) are always correctly centered over a combustion chamber and are pushed in the middle. The valves (6) will otherwise be damaged. Follow the operating instructions for the assembly device manufacturer (01).
6	Connect compressed air to assembly device (01) and open compressed air valve.	Follow the operating instructions for the assembly device manufacturer (01).
7	Compress valve spring (3) with assembly lever (03).
8	Remove valve keepers (4).	Installation : Ensure that the valve keepers (4) are reliably seated. Magnetic pin	Fig 3
9	Remove upper valve spring retainer (2) and valve spring (3).
10	Use pliers (07) to remove valve stem seal (5). Specified engine oils (service) - Overview		BB00.40-P-0223-02A
		: Lubricate the new valve stem seals (5) with engine oil and press on using a drift (08). During assembly, ensure that the valve stem seals (5) with the brown seal are installed on the exhaust side and that those with the green seal are installed on the intake side.	AR05.30-P-3500-02MM
		Pliers	Fig 6
		Drift	Fig 5
	Check
11	Check valve spring (3) for damage.	If damage is present ↓ Replace all valve springs (3).
12	Check top valve spring retainers (2) and bottom valve spring retainers (7) for score marks, cracks, and pitting.	If score marks, cracks, or pitting are present, ↓ Replace upper and lower valve spring retainers (2, 7).
13	Check valve stems for formation of burrs and pitting. General information on checking valves, valve seats and valve guides	If ridging is present on the valve stems, ↓ Deburr valve stem. If pitting is present on the valve stems, ↓ Replace valves (6)	AH05.30-P-1000-02SZ
14	Install in the reverse order.