| t
| Before widening remove the regulation elements and then drill the expansion valve using a suitable drill bit (diameter 6 mm for example). |
| t
| Expansion valves exist with different versions and with different structures. In case of the version -A- remove for example the parts -B-, -C- and -D-. For the component -D- the part -E- (regulation element) must be removed. The expansion valve must then be drilled in the area -F- using a suitable drill bit |
| t
| For the version -G- remove the parts -H-, -I- and -K- then drill the zone -L- using a suitable drill bit. |
| t
| Clean the widened expansion valve and remove the remains (shavings) |
| t
| Now fit the parts -B-, -C- and -D- for the version-A- or the part -H- for the version -G- |
Note | –
| Check the quantity of refrigerant in the air-conditioning service station, this should contain a minimum of 7 kgs of R134a refrigerant |
Note | Switch on the heater connected to the refrigerant bottle 30 minutes before carrying out the first rinsing procedure. This increases the pressure in the refrigerant tank and accelerates the filling of the rinsing circuit. |
| –
| Empty the used oil tank on the air-conditioning service station |
| –
| Connect the feed hose (high-pressure side) of the air-conditioning service station using the adapter to the low pressure pipe going to compressor (this is the widest pipe). |
| –
| Connect the return hose (low pressure side or vacuum side) of the air-conditioning service station to the output of the refrigerant circuit rinsing equipment. |
| –
| Connect the input of the refrigerant circuit rinsing equipment using the adapter to the high-pressure pipe going to the compressor (this is the thinnest pipe). |
Note | t
| Components should always be rinsed in the opposite direction of flow of refrigerant in the air-conditioning system during normal operation. → Chapter |
| t
| When flushing, impurities from the refrigerant circuit ingress into the refrigerant circuit flushing attachment and the air conditioner service station, where they are retained in the built-in filters and dryer. Depending on the nature of the impurities, these components are to be replaced more frequently in line with the operating instructions for the air conditioner service station or the refrigerant circuit flushing attachment (refrigerant circuit flushing attachment filter after approx. 5 to 10 flushing cycles depending on the level of contamination of the refrigerant circuits flushed). |
| t
| Depending on the nature of the dirt (oil used by refrigerant machines and particles created by wear and abrasion of the compressor) deposits are made on the spy hole of the refrigerant circuit rinsing equipment. If necessary, clean the spy hole after rinsing and, for monitoring purposes, rinse the refrigerant circuit one more time (one rinsing cycle is sufficient this time). |
| t
| The liquid refrigerant cannot be driven at the necessary speed through the expansion valve, hose clip and dehydration bags in certain liquid tanks; for this reason these components must be removed from circuit and replaced with adapters if necessary → Heating, air-conditioningor → Air-conditioning |
| t
| Adaptors for the air-conditioning service station and bridging of certain components in the refrigerant circuit. |
| –
| Activate the air-conditioning service station and rinse the refrigerant circuit (for about 1 or 1.5 hours for each of three cycles) |
Note | t
| The rinsing must be carried out exactly as described in the instructions manual of the air-conditioning service station. |
| t
| Depending on the version of the air-conditioning service station, the used oil container only has a capacity of about 125 cm 3; if a system has to be rinsed that has a larger quantity of oil, the used oil container may have to be emptied after the first operating procedure of a rinsing circuit. |
| t
| Observe refrigerant flowing back into AC service station. The circuit can be considered to be clean only when the refrigerant flowing back into the AC service station is transparent and fully colourless in the observation window in the flushing device for AC circuits. |
| t
| For rinsing, all of the refrigerant machine oil in the circuit is washed out (except for minimum residues for example in the evaporator f that may be disregarded). |
| t
| For particularly intense soiling of the refrigerant circuit, rinsing maybe required twice (2 rinsing cycles with three rinsing operations each cycle). |
| Sequence of rinsing operations (the sequences automatic following a program of the air-conditioning service station) |
| t
| After switching on, the rinsing cycle (refrigerant circuit with connection hoses and rinsing device for refrigerant circuits) is first evacuated and the refrigerant circuit thereby checked for leaks. (depending on the version of the air conditioner service station, manual switching to next step may be necessary). |
| t
| The emptied refrigerant circuit is loaded from the high-pressure side of the air-conditioning service station (in the opposite direction to normal flow of the air-conditioning through the low pressure side of the refrigerant circuit of the vehicle) with a specific quantity of refrigerant (for example 5 kgs) or until the refrigerant circuit and the spy holes of the refrigerant circuit rinsing equipment are filled to a maximum with liquid refrigerant (according to the air-conditioning service station version refrigerant may not flow for a short time). |
| t
| Once specified quantity of refrigerant has been loaded into the system, depending on the version of the air-conditioning service station and the refrigerant circuit rinsing equipment, the heating for the printing equipment is activated (only if the refrigerant is expelled from the refrigerant circuit rinsing equipment in a gaseous form). |
| t
| After evacuating the refrigerant, switch off the heater for the flushing device for AC circuits (if present). Depending on the version the AC circuit may be evacuated again, and after evacuation the AC service station separates the refrigeration oil evacuated from the circuit. |
| t
| The refrigerant filling process, vacuuming (and evacuation) is repeated 2 times (that is, it is completed three times in all). |
| t
| After the third vacuuming, the rinsing circuit is evacuated depending on the version of the air-conditioning service station. |
| –
| After completion of the flushing cycle, check the observation window in the flushing device for AC circuits. If contamination is present it may be necessary to clean the flushing device for AC circuits or the AC service station in conformance with the operating instructions and flush again for purposes of checking (one flushing operation of approx. 30 minutes is sufficient). |
| –
| Check pressure in AC circuit. Pressure should not be present in the circuit (if necessary relieve again momentarily). |
| –
| Remove the connections from the vehicle to the air-conditioning service station on the refrigeration circuit (there should be no positive pressure in the refrigeration circuit) |
| –
| Depending on the complaint the compressor may need to be replaced → Heating, air-conditioning or → Air-conditioning and → Spare parts catalogue or the refrigerant machine oil must be emptied from the removed compressor (replace components of the refrigerant circuit) then refill with the quantity of refrigerant machine oil specified (special oils and oil quantities for refrigerant machines) |
Note | t
| Replacement compressors come with the specific amount of oil for refrigerant machines. For machines with two evaporators, if necessary, add the required amount of refrigerant machine oil to the circuit → Heating, air-conditioning or → Air-conditioning and (special oils and oil quantities for refrigerant machines). |
| t
| If the compressor is not to be replaced then the amount of refrigerant machine oil must be corrected (empty to move the refrigerant machine oil then put the correct quantity into the compressor or the refrigerant circuit) (replace components of the refrigerant circuit) and (approved refrigerant machine oils and filling quantities). |
| –
| Empty and fill the refrigerant circuit as specified and |
|
|
|
WARNING
Caution
