Some JDM '90 models had a fatter booster housing compared to the ADM '90 models that had the 'slimline' housing.
Boosters were updated in late'91, and 11/93, but both of these look the same as ADM '90 model booster except for the vacuum connection.
 
 
 

Ok cool thanks guys. So it's a 91 JDM with a fat booster, if I went with a late slim booster I'd need to fluid lines to suit? And I read something about an external valve on the newer items?

Early model boosters had the vac control valve mounted on the booster itself, while later models had them located nearer the motor, with different p/ns for pre and post 11/91 valves.
Check out Toyodiy for diagrams and p/ns.
 
I've also noticed that the slimline boosters were changed again after late '97, making 4 different types.

You will also need to bend the disc shields away a bit to give clearance to the bigger rotors, no biggie.
 
Current car has the later discs and calipers, and early MC/booster.  Has been like that for years.  I now have the later MC/booster, cant wait to fit them, supposed to make a big difference to pedal feel.
 
Cheers

Also ABS and non ABS MC are different, I understand the pipe connection location points are changed.
 
Cheers
 
 

artymr2
Current car has the later discs and calipers, and early MC/booster.  Has been like that for years.  I now have the later MC/booster, cant wait to fit them, supposed to make a big difference to pedal feel.

 
Sorry to revive a thread that's several years old, but artymr2, I'm very interested to hear what you thought of the pedal feel differences when switching from a 92+ brakes and Rev.1 booster/MC setup to a 92+ brakes and later model booster/MC.
 
I'm in the process of changing to the 92+ calipers/rotors.  At my diposal, I have the Rev.1 booster/MC installed on the car (w18 booster and 7/8" MC).  From the donor car, I have the w53 booster (which I think is the ABS one??) but a 1" MC that is non-ABS from some unknown Toyota model.  Unfortunately, I learned that the w53 booster doesn't have the check valve on it like the w18 one does... and am very tempted to just stay with the w18 booster / 7/8" MC instead of sourcing and routing another check valve.
 
What's the difference between the w18 and w53 boosters aside from vacuum port and check valve?  from an initial glance they look very similar.

ansys, the vacuum check valve relocate is no big deal. It is just a 10 mm one way valve fitted in the hose coming from the engine intake manifold, and I used a Honda one. The hose in the front trunk just connects directly to the booster.
 
On my '90 model ADM SW20 NA I still have the early small brakes that I have found totally adequate, however in an attempt to get rid of the 'springy' brake pedal feel, I fitted a '97 turbo booster with a one inch diameter brake M/C.
The result was just what I wanted with a firm pedal and much shorter travel, and not much pedal pressure needed. 
 
BTW, I have run the car with both the '90 booster and the '97 booster and found that even though they look much the same the difference in power between the two was quite dramatic so the internals are obviously different!!
 
Also be aware that I believe SW20 boosters were changed to more powerful ones after 11/91, and then to even more powerful ones after 11/93, but I don't know what the part numbers are.                                                                  Unfortunately there are no markings on the '97 booster I fitted.

Thanks for that.  Yeah, stopping power wise I find the rev.1 brakes just fine normally.  However, when I abused them with my poor driving on the track, they don't seem to resist fading very well.  So, even though it's kiiling me to add more weight to the car, the plan is to upgrade to 92+ calipers/rotors, braided brake lines, and then who knows for the booster/ MC.  I might just leave it, cause when the rev.1 brakes were working well, the pedal feel felt OK to me. 

I've also done the change from early model non ABS braked car to later model discs, calipers, master cylinder, booster and proportioning valve. Finally found a 15/16 inch master cylinder to be optimal with a large diameter (slim) late model booster. I can also recommend Forza FP3 pads from Brakes Direct. I placed an all steel vacuum check valve close to the inlet manifold. I used genuine thick walled vacuum hose too !!