Connect/Disconnect Test Valve Block At Hydraulic Unit - AR77.37-P-4205W

MODEL 172.4 

Courtesy of MERCEDES-BENZ USA

Courtesy of MERCEDES-BENZ USA

	Connect/disconnect
	Risk of injury  to skin or eyes caused by hydraulic fluid spraying out under high pressure. Risk of poisoning  caused by swallowing hydraulic fluid	Depressurize the hydraulic system completely before starting any work on the system. Wear protective clothing and safety glasses.	AS00.00-Z-0013-01A
1	Remove crossmember cover (5) from Vario roof crossmember (8) until the Vario roof control hydraulic cylinder (A7/5) is accessible		AR77.37-P-3500W
2	Fold up insulating mat (20) and secure against falling down
3	Unclip hydraulic wiring harness (7) form Vario roof crossmember (8)
4	Open cable tie (17) and disconnect electrical connector on Vario roof control hydraulic unit (A7/5x1)	:  Replace cable ties (17).
5	Unhook Vario roof control hydraulic unit (A7/5) from rubber mounts (21) and lay down in vehicle interior on suitable base such as foam rubber mat covered with cloth.	Lay down Vario roof control hydraulic unit (A7/5) as shown. Otherwise, the vehicle interior can be soiled with hydraulic fluid running out. Escaping hydraulic oil causes an unpleasant odor and is hard to remove.
6	Open emergency operation valve (11) one turn	Emergency operation valve (11) remains open.
7	Prepare valve block (1)		AR77.37-P-4205-01V
		Testing unit	Fig 1
		Set of stop plugs	Fig 2
		Valve block	Fig 3
8	Remove connection plates (13, 14) on hydraulic unit valve block (16)	If only the system pressure in the hydraulic system is tested, remove only connection plate (13). Test system pressure using the connection no. 53 on hydraulic unit valve block (16).	*BA77.37-P-1002-01A
9	Remove stop plugs (15) from valve block (1), pull hydraulic lines (12, 22, 33, 42, 53) out of hydraulic unit valve block (16) and connect to valve block (1)	Reconnect hydraulic lines (12, 22, 33, 42, 53) individually. Pull stop plugs (15) out of valve block (1) immediately before connecting. Immediately close connections on hydraulic unit valve block (16). Otherwise, the vehicle interior can be soiled with hydraulic fluid running out. Do not pull hydraulic lines (12, 22, 33, 42, 53) too forcefully. Otherwise, the installation position can change and the hydraulic lines (12, 22, 33, 42, 53) can be damaged when moving the Vario roof. Set of stop plugs	Fig 2
		The shutoff valves (9) on the valve block (1) must be open. Observe connection schematic for hydraulic lines (12, 22, 33, 42, 53) on valve block (1): ↓ Connection scheme for pressure test	AR77.37-P-4205-02V
		Valve block	Fig 3
10	Tighten connection plate (18) on valve block (1)	Ensure that connection plate 18) is seated correctly. Otherwise the hydraulic lines (12, 22, 33, 42, 53) can detach during the pressure test and hydraulic oil can spray out of the connections. Valve block	Fig 3
11	Connect adapter line (6) on valve block (6) to connection no. 53 on hydraulic unit valve block (16)	Valve block	Fig 3
12	Connect test lines (19) to corresponding connections on hydraulic unit valve block (16) and install connection plates (13, 14)	Connect test lines (19) one at a time. Remove stop plugs on test lines (19) and hydraulic unit valve block (16) immediately before disconnecting. Otherwise, the vehicle interior can be soiled with hydraulic fluid running out. Ensure that connection plates (13, 14) are seated correctly. Otherwise the test lines (19) and the adapter line (6) can detach during the pressure test and can spray out of the connections. Observe line coding on hydraulic unit valve block (16).	*BA77.37-P-1002-01A
		Valve block	Fig 3
13	Turn Vario roof control hydraulic unit (A7/5) to installation position and install with rubber mounts (21) to Vario roof crossmember (8)	The Vario roof control hydraulic unit (A7/5) must be in the installation position to perform the pressure test.
14	Close emergency operation valve (11).		*BA77.37-P-1001-01A
15	Connect electrical connector to Vario roof control hydraulic unit (A7/5x1)	The pressure test can now be started.
16	Disconnect in reverse order	Disconnect hydraulic lines (12, 22, 33, 42, 53), test lines (19) and adapter line (6) separately or reconnect and plug immediately. Also plug connections on valve block (1) immediately after pulling out hydraulic lines (12, 22, 33, 42, 53) Otherwise, the vehicle interior can be soiled with hydraulic fluid running out. Set of stop plugs	Fig 2
		Valve block	Fig 3
17	After disconnecting the test tools and before installing the Vario roof control hydraulic unit (A7/5), bleed hydraulic system by opening and closing the Vario roof several times with the Vario roof actuation switch.

SOFT TOP HYDRAULIC COMPONENTS

Number	Designation			Model 172
BA77.37-P-1001-01A	Emergency operation valve at hydraulic unit		Nm	2.5
		See picture		-
BA77.37-P-1002-01A	Bolt, connection plate to hydraulic unit		Nm	4

Fig 1: Identifying Tester (126 589 14 21 00)

Courtesy of MERCEDES-BENZ USA

Fig 2: Identifying Record Plug (129 589 00 91 00)

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Fig 3: Identifying Valve Block (172 589 00 91 00)

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