Hello sorrelnationdory and welcome to the forum!
I see you wrote ‘…source the Haynes manual…’. I’m not aware that Haynes ever made a manual for the Hiace, possibly because the Hiace was never very popular here, so I’m interested to know where you might have seen or heard of one? I’d certainly be keen to get hold of one as the Haynes docs are quite good.
Take a look at this short post for a host of useful links, resources and other manuals:
https://hiace-super-custom.forumotion.com/t4468-part-numbersWhile short it’s got a lot of useful stuff including the Electronics Parts Catalogue etc.
Toyota publishes its manuals as a series of numbered documents called Repair Manuals and supplements and I think these are largely better than Haynes’ manuals however, I’ve never found a list of RM numbers against specific vehicles. There’s also often a RM for the vehicle and another for the engine and another for certain other parts, such as a transaxle. I know RM123 covers my 3L engine, but I’ve not been able to track down that publication. RM156 seems to be the closest match to my ~92 LH119 but I’ve found quite a few occasions where measurements, tolerances and torque values are definitely wrong. eBay, which isn’t usually great (in my opinion) for parts, has listings for lots of second hard RMs to show how this works in theory. Problem is that the only manuals that are likely to be bob-on correct for 90s JDM vehicles are printed and in Japanese.
I expect that if you’re used to a single Haynes manual to cover a complete vehicle, which also breaks down every element into lots of simple steps then you’re going to be disappointed. The above Forum thread will lead you to a lot of understanding and knowledge of servicing, capacities and good manuals (depending on your exact van, which you can also decode there), plus parts, their numbers etc etc. Hopefully your van came with a decent amount of paperwork and a handbook to show you what’s what. Hiaces are generally not complex vehicles, at least by today’s standards, but do require that you do your homework (a bit) before diving in.
I keep meaning to write a comprehensive post on manuals and parts searching but this will get you going!
Good Luck and HTH!