Brake Booster Needed - Very Specific Dimensions

[Advrider639]

I need a brake booster for my 40 series. Going to be using a FJ80 master on it. Disc brakes on all four corners.

Diameter: Max 8 1/4"
Firewall Studs: Min 1 5/8"
Push Rod: Min 2 3/4"

Can anyone recommend one, that's small in diameter, but has long firewall studs (going to be using a spacer to keep it off firewall)? The one I currently have would be perfect, but the push rod and studs are not long enough.

Currently looking at early 90's toyota pick up, 2wd, since they have longer studs. The diameter is what concerns me... I see no real dimensions online.

Thanks!

 

[B y r o n]

Have you ever considered a hydro boost conversion?

 

[calen]

Have you ever considered a hydro boost conversion?

hahaha old thread but this is the first ive seen someone suggest hydro boost on a 40, my patrol homie has been preaching the joys of his, adnn theres a marks 4x4 one for 80 series which i assume also fits 40's. have you done this? and is there a way to get the hydro booster from anyone but Marks? they jsut tuse a booster from some other truck with some minor mods no?

 

[B y r o n]

I haven't but this guy has.

 

[sofj45]

Have hydro boost on one of our 55s no complaints.

 

[POPO AGIE]

When I installed the Toyota double diaphragm booster I found that I needed the rectangular spacer that I got from City Racer and then had clearance for the new clutch master cylinder. They are not very expensive. Red Line sold me the brake components and now include the spacer.

 

[calen]

I haven't but this guy has.

dang, that looks crazy, the marks one seems a little more low profile (shorter assembly) when i got the dough ill dive into this more. for the time being im gonna run the 80 series master and booster

 

[calen]

related booster question. had to replace my Master cylinder, and had planned to do the 80 series MC and booster, but the booster will take a little longer to acquire, but i have the MC and need to use the truck. Im correct in thinking the 80 master still fits on the 40 booster? all 4 bolt parts. about to do this in like an hour from now but thought id save myslef a little headache if someone knows they dont fit and responds before I start hahaha. other wise ill find out myself lol

 

[Pighead]

Im correct in thinking the 80 master still fits on the 40 booster?

It fit on a 55 booster, I bet it will fit a 40.

 

[calen]

It fit on a 55 booster, I bet it will fit a 40.

awesome, thank you. about to determine right now was the braking improved with jsut the 80 MC upgrade? I am gonna throw a 80 booster in but just curious guess ill know for myself in a couple hours lol

 

[Pighead]

was the braking improved with jsut the 80 MC upgrade?

I don't really drive my Pig hard enough or fast enough to notice any difference in braking with the 80 MC. I had great brakes with the stock MC and still had great brakes after the swap.

 

[calen]

welp, it fit just right, no problem. pedal was soft on the way to work but still stopped her real good. gonna do one more bleed and hit the whipsaw tomorrow thanks for the knowledge.