diesel water pump from a t25 on a t3 passat

[happycampers]

Hello
I have a T25 camper which was originally an Aircooled petrol. It's now got a 1.6TD engine from a 1992 VW Passat. It run's ok but get's hot in traffic. I assume this may be because the water pump in the Passat engine was designed to circulate coolant around a 2 metre area, whereas now in the T25 it'c circulating coolant around 10 metres so struggles to cope. My question is I assume the T25 1.6TD waterpump has a greater flow rate than that in the 1.6TD B3 Passat.
But would the 1.6TD water pump from the diesel 1.6TD T25 fit directly onto the Passat 1.6TD. They are the same block I think but the 1.6TD from the T25 was produced up to 1989, whereas the Passat 1.6TD is a 1993 year and I assume although the block is the same the sundries may be of different spec.
The Passat engine code is an SB. Therefore the waterpump is probably a FWP1696. However the 1.6TD T25 waterpump at just campers is J13449.
Basically does the T25 diesel watewr pump have a higher flow rate and would it bolt straight onto a 1.6TD Passat engine?
Thanks

[Oldiebut goodie]

Flow rate is governed by the pulley size, impellers are the same size. Belt set up is? JX or ? V or flat? Differing pumps have different direction of rotation depending upon belt setup/type.
Ignore Just Krappers part numbers - they mean nothing to anyone not even Just Krappers!

Most probably need a new thermostat, try putting an 82 degree one in or even 80 degree instead of the 85 degree.
Or radiator fan not operating? Was a watercooled front panel put on with the radiator?
Hard to know where to begin with a mongrel van - who knows what has been done to it. A full description of work done to carry out the conversion would be of help.
Hello.

[ewenmaclean]

Hello,

exactly WHS^^^^ - I think going for a water pump flow rate diagnosis is seriously premature, not to say almost certainly not the problem. If you want to check out part numbers and compatibility you can go on vagcat, and then you're talking about vw part numbers not jk ones, which are pretty much useless. Pictures of rad, rad fan and belt setup would be useful....

Ewen

[ewenmaclean]

quick bit of vagcat reading gives part numbers for the two:

T3 (or T25):
037121010C (whole water pump)
026121005JX (impeller and housing)

Passat
037121010BX (whole water pump)
037121005C (impeller and housing)

googling seems to suggest the impeller orientations are the same

[Oldiebut goodie]

If it is a flat belt set up the impeller run t'opposite way to the v belt - this is where several people have come unstuck. You will get some flow but not enough. I had to change pump to keep the v belt set up when I changed to the 1Y (ex '98 Caddy) which had the flat belt.

[weldore]

And the serpentine belt can fit the pump pulley either side and still seem right.

[adyjoad]

Those pumps are notorious for the plastic impeller to crack and slip on the spindle. Easy to check, take the thermostat housing off and you can just see the impeller, it should be locked to the spindle. Any doubt just stick a new one on.

[dandelor]

And the serpentine belt can fit the pump pulley either side and still seem right.

Hi - Im getting the same issues with overheating - My AAZ's from a 90's passat with a flat belt system, and I'm almost certain the pump and housing are original to the engine.
Could it be that my pump is turning the wrong way as you suggest? If so how do I swapp it round? It looks like the tensioner wheel would get in the way, and that there's barely enough room to have the belt come around the inside of the pulley. Or should I opt for a new JX style pump to keep the belt set-up I have? Any help would be fantastic as I'm worried I'm gonna fry my second 2nd AAZ!
I have an image of the current set up but I don't think attachments are allowed on this board as I can't seem to upload....
cheers,
dan

[syncroandy]

Re. impeller, the best I've seen are cast bronze/brass (a German Hepu pump I had on the shelf for years), the cheapest looking are probably the thin pressed steel ones used on the pumps that come in blue boxes with 'Kolbenshmidt' printed on. I very much doubt they're made by KS or in Germany..