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So the Yeti needed a new electric water pump. The old one sprung a leak like a sieve when warmed up. Pressure tested normal when cold.
Theoretically this is a simple job. Three screw and 2 hose clips. But it is rather not simple when the engine is in the vehicle. Will be a lot quicker next time..... now that I know which goldilocks tools to use.
Last part - disconnect the lower radiator hose and the hose on the oil cooler to drain the cooling system. Looks like the whole world struggles with disconnecting the plastic connector clip-on hoses. This is worse when you can hardly get a hand on the fitting to start with. Most suggest to use some spray lubricant. VW manual says only to lubricate coolant hose/fittings with coolant mix. Didn't find anyone suggesting this trick.
THE TRICK - PRESSURISE THE COLD COOLING SYSTEM . About 1.5bar (~20psi) seem good - equivalent to the radiator cap pressure. Use a cooling system pressure test pump (VAG 1274 equivalent). I got a VEVOR kit with all the adapters and the equivalent of the VAS 6096 cooling system charge unit for about $55. The only thing not in the kit is a VW radiator cap pressure test adapter. But one of the adapters has the correct thread so can be modified by removing the internal part with o-rings. - need a 10x1mm nut and washer/seal to attach the connector to the back of the internal threaded screw cap.
Trick A: For rubber hoses without o-ring connectors, the pressure of coolant lets the coolant separate the rubber from the pipe and lubricate with coolant. Remove the clips. Push the hose onto the fitting a bit harder to expand the diameter and wiggle round to get the coolant under the hose. Some will squirt out which is good. Depressurise. Loosened hoses slide off fairly easily.
Trick B: For the clip on plastic connectors with o-rings, the pressure in the cooling system does the work of pushing the connector off. Still need enough access to get a hand on the connector to wiggle it round while the pressure does the pushing. Doesn't take long with 10-15kg of assistance force pushing the connector off, without risking causing any damage to the connector or radiator. Only hard part of the trick is to figure how many mm loosening to use pressure assistance before reducing or releasing the pressure when it will come off easily by hand. Somewhere around 4-6 mm I think. Didn't manage to stop in time before the connector blew off and coolant sprayed everywhere! So much for trying to collect the old coolant in a tray/bucket.
PS
The VEVOR kit is fairly good quality. I have been impressed with the quality and price of all the things I have bought from VEVOR (which started with a machinist's precision vice). The VEVOR instructions on using the cooling system charge gadget are useless. Need to read the VAS 6096 instructions presumably in most VW engine service manuals. VCDS is required to fill/bleed the cooling system using the VAS 6096 method. The cooling system vacuum is generated by the vehicle electric coolant pump.
My sister had to have an emergency water pump change on her Golf 7 GTI while on holiday last week. Still waiting to find out which water pump - electrical or belt driven. The mechanic damaged a radiator hose in the process - I suspect trying to get the radiator hose connector off. Somehow they patched it. A set of upper and lower radiator hoses for mk7 GTI are >$400 non-genuine!
Theoretically this is a simple job. Three screw and 2 hose clips. But it is rather not simple when the engine is in the vehicle. Will be a lot quicker next time..... now that I know which goldilocks tools to use.
Last part - disconnect the lower radiator hose and the hose on the oil cooler to drain the cooling system. Looks like the whole world struggles with disconnecting the plastic connector clip-on hoses. This is worse when you can hardly get a hand on the fitting to start with. Most suggest to use some spray lubricant. VW manual says only to lubricate coolant hose/fittings with coolant mix. Didn't find anyone suggesting this trick.
THE TRICK - PRESSURISE THE COLD COOLING SYSTEM . About 1.5bar (~20psi) seem good - equivalent to the radiator cap pressure. Use a cooling system pressure test pump (VAG 1274 equivalent). I got a VEVOR kit with all the adapters and the equivalent of the VAS 6096 cooling system charge unit for about $55. The only thing not in the kit is a VW radiator cap pressure test adapter. But one of the adapters has the correct thread so can be modified by removing the internal part with o-rings. - need a 10x1mm nut and washer/seal to attach the connector to the back of the internal threaded screw cap.
Trick A: For rubber hoses without o-ring connectors, the pressure of coolant lets the coolant separate the rubber from the pipe and lubricate with coolant. Remove the clips. Push the hose onto the fitting a bit harder to expand the diameter and wiggle round to get the coolant under the hose. Some will squirt out which is good. Depressurise. Loosened hoses slide off fairly easily.
Trick B: For the clip on plastic connectors with o-rings, the pressure in the cooling system does the work of pushing the connector off. Still need enough access to get a hand on the connector to wiggle it round while the pressure does the pushing. Doesn't take long with 10-15kg of assistance force pushing the connector off, without risking causing any damage to the connector or radiator. Only hard part of the trick is to figure how many mm loosening to use pressure assistance before reducing or releasing the pressure when it will come off easily by hand. Somewhere around 4-6 mm I think. Didn't manage to stop in time before the connector blew off and coolant sprayed everywhere! So much for trying to collect the old coolant in a tray/bucket.
PS
The VEVOR kit is fairly good quality. I have been impressed with the quality and price of all the things I have bought from VEVOR (which started with a machinist's precision vice). The VEVOR instructions on using the cooling system charge gadget are useless. Need to read the VAS 6096 instructions presumably in most VW engine service manuals. VCDS is required to fill/bleed the cooling system using the VAS 6096 method. The cooling system vacuum is generated by the vehicle electric coolant pump.
My sister had to have an emergency water pump change on her Golf 7 GTI while on holiday last week. Still waiting to find out which water pump - electrical or belt driven. The mechanic damaged a radiator hose in the process - I suspect trying to get the radiator hose connector off. Somehow they patched it. A set of upper and lower radiator hoses for mk7 GTI are >$400 non-genuine!