Remove/install piston rings

AR03.10-S-7311PD

Remove/install piston rings

06.03.2020

Engine

699 in model 470, 471

1

Plain compression ring

2

Taper-faced hook scraper ring

3

Bevel-edged ring (oil scraper ring)

4

Piston

 Caution

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

 Caution

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

Topical note

Notes on avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A

Notes on the assessment of pistons and piston rings

AH03.10-P-0001-04MN

 

Remove/install

1

Remove piston (4).

AR03.10-S-7021PD

2

Determine side clearance of the plain compression ring (1), taper-faced hook scraper ring, (2) and bevel-edged ring (3).

 Commercially available devices/tools
Feeler gage

Piston ring vertical clearance

*BE03.10-N-1001-05PD

If the vertical clearance is excessive,



Install new piston (4), plain compression ring (1), taper-faced hook scraper ring (2), and bevel-edged ring (3).

3

Remove plain compression ring (1), taper-faced hook scraper ring (2), and bevel-edged ring (3) from the piston (4) with pliers.

 Installation: Observe installation position of plain compression ring (1), taper-faced hook scraper ring (2) and bevel-edged ring (3). Install plain compression ring (1), taper-faced hook scraper ring (2) and bevel-edged ring (3) with piston ring end gap offset at 120°.

 Pliers

*000589513700



Clean

4

Clean grooves of the plain compression ring (1), taper-faced hook scraper ring (2), and bevel-edged ring (3) in the piston.

Assembly cleaner

*BR00.45-Z-1028-04A

5

Clean cylinder barrel.

Assembly cleaner

*BR00.45-Z-1028-04A



Check

6

Check plain compression ring (1), taper-faced hook scraper ring (2), and bevel-edged ring (3) for damage and chippings on the coating.

If damage or chippings are present on the coating,



replace plain compression ring (1), taper-faced hook scraper ring (2), and bevel-edged ring (3).

7

Determine end gap of the plain compression ring (1) and taper-faced hook scraper ring (2).

 Insert plain compression ring (1) and taper-faced hook scraper ring (2) in the unworn area of the affected cylinder.

 Commercially available devices/tools
Feeler gage

Piston ring end gap

*BE03.10-N-1002-05PD

If the end gap is excessive,



replace plain compression ring (1), taper-faced hook scraper ring (2), and bevel-edged ring (3).

8

Install in the reverse order.

Check values for piston rings

Number

Designation

Engine 699 in model 470, 471

BE03.10-N-1001-05PD

Piston ring vertical clearance

Groove 1

mm

0,09...0,13

Groove 2

mm

0,03...0,07

Groove 3

mm

0,05

Check values for piston rings

Number

Designation

Engine 699 in model 470, 471

BE03.10-N-1002-05PD

Piston ring end gap

Groove 1

mm

0,23...0,38

Groove 2

mm

0,60...0,80

Groove 3

mm

0,25...0,50

Repair materials

Number

Designation

Order number

BR00.45-Z-1028-04A

Assembly cleaner

A 000 986 56 01