Early Coolant Systems - There were two different types
Recently my expansion tank sprung a leak and I found that quite a number of my pipes etc were obsolete yet quite a lot of early pipes were still available and this is how I found out that VW used two different early cooling systems. So now my cooling system has a degree of future proofing in case something goes wrong in the Highlands again
When VW made the first watercooled T25 they created an early cooling system but after about a year they changed a few things. They changed the expansion bottle and bracket as well as the pipes that came from the bottle to the waterpump and the long metal pipe that goes accross the engine by the carb. They also changed the two long coolant pipes that went around the back of the engine as well as the bleed valve.
MK1 early system parts are long obsolete
Mk2 early system parts are all available apart from the expansion bottle bracket (2nd hand??)
Here's the early system MK1
Expansion bottle and two moulded pipes that run from it (note ports on bottle are offset
068-121-405D Bottle (obsolete - not to be mixed up with the “B” diesel version as the ports are smaller)
025-121-130 & 025-121-108 Pipes (obsolete)
171-121-140D plastic joining piece between above pipes (VW Heritage)
321-121-321 metal expansion bottle cap (Brickwerks)
Bottle retaining Bracket unknown number
025-121-421A Small bleed valve obsolete
025-121-073 & 025-121-103 pipes obsolete
Here's the early system MK2
025-121-408A Expansion bottle (brickwerks/heritage)
025-121-409D expansion bottle bracket (obsolete – 2nd hand)
025-121-321B Expansin bottle cap (Brickwerks)
025-121-130A Pipe (Heritage)
025-121-108A Pipe (Heritage)
N90128703 short pipe (obsolete but just standard 25mm hose x 58mm long)
N90166601 short pipe (obsolete but just standard 32mm hose x 58mm long)
025-121-438 ‘H’ shaped joining piece (Heritage)
025-121-082 Larger bleed valve (Heritage/Justkampers)
025-121-062 upper right pipe ((Brickerks silicone)
025-121-102 lower right pipe (Brickerks silicone)
012-121-073E upper left pipe (Brickerks silicone)
025-121-103C lower left pipe (Brickerks silicone)
So there’s the differences.