Brake Boosters and 3FE

[DomSmith]

After some major time on the back burner I’ve been able to make some progress on my 3FE install on the 65 SWB. I’ve read countless threads and it seems like there are quite a few 40’s and even 45’s with the 3FE and most do not specify interference with the 3FE and brake boosters. I did see that a few guys have scabbed in a newer firewall and maybe that’s why they don’t have an issue?

There is really no chance in hell mine fits even with the small geo metro booster. There are definitely a few options to resolve this but I wondered why it’s not discussed more?

It seems like most don’t have major interference or just opt for a slightly smaller booster. Is the brake setup on the early trucks “inboard” more than the early to mid 70’s rigs?

Appreciate any insight.

 

[c2dfj45]

When I did my first 3FE conversion on my 45LPB, I immediately saw that the master was going to be a big deal. We've got the ability to modify anything we need to make things fit so none of it is a big deal but time is. And I have an aversion to cutting sheetmetal in old trucks. A non-boosted dual circuit master wasn't an option(which is probably what a lot of people do because it's easy) so I went with my electrically boosted master. I love it. Pricey for sure but it saves countless hours of labor which in my world, pays for itself. Less time on my trucks, more time on customer paying work.

I've run my setup on 3 trucks now. It just barely clears. They are all mounted on early trucks with a rib. I have a 71 40 that doesn't have a rib that will get my setup on it next when a 3FE goes in. I'm curious to see if I can some how try and use the booster on that one(probably a late 70s) as I really like the brakes. I don't see it happening easily though.

I was poking around my trucks this morning....i have a 78 in the shop and my LV. My LV measures roughly 13" from the center of the master cylinder opening to the corner of the cowl/upper bib/fender. The 78 measures 11". So the master is over 2" more on a non-rib truck(not sure if ALL non-rib trucks are the same or not). That's a lot but those 3FEs have huge plenums on them...they take up a ton of room. Maybe moving the motor up and over a little? Not sure. Seems like a lot of work. Maybe a custom plenum on the 3FE? Lots of work.

Even if a booster cleared the plenum, there is still the ebrake mount and throttle cable on the firewall right there....plus the clutch master. Lots to work around....

 

[xtremeVA]

I've been avoiding this topic but will face the hurdle because @c2dfj45 inspired me to go with an FE setup. It looks like moving mounting holes, and grafting in a later model brace that jogs to the left will be necessary. Yep, lots of work.

I Have also looked at a Toyota MR2 booster.... but still need to move the mount holes and brace.

You cut first...I'm right behind you.

 

[c2dfj45]

I've been avoiding this topic but will face the hurdle because @c2dfj45 inspired me to go with an FE setup. It looks like moving mounting holes, and grafting in a later model brace that jogs to the left will be necessary. Yep, lots of work.

I Have also looked at a Toyota MR2 booster.... but still need to move the mount holes and brace.

You cut first...I'm right behind you.

Glad I could be your inspiration...you'll love that 3FE in the truck. All that work on the brakes will be worth it. It's really a perfect motor. Too bad they are becoming hard to get these days....

 

[DomSmith]

Thank you both for the input. I’ve got a few options to try before I cut the firewall and move the booster over.

C2 thanks for taking the time for measuring etc. I may end up with the brake master you suggested here and in my build thread but will look for other options before I spend the big $$$. I agree that there really is an equal amount of either time or money involved. I just need to decide which one I want to do.

 

[c2dfj45]

I know for me, not cutting the rib was really important but I'm weird when it comes to stuff like that. I'm really into this preservation mode now....have been for a while the more I think about it. I'm also into brakes that are very safe and as good as any modern system(minus ABS I suppose). I drive all my junk fast and I love brakes that work. The systems we use are safe and work extremely well. They work for us and our projects. So many ways to make it happen though....I'll be curious to see how you do it. I might borrow some of it when I go to work on my 71. Not sure I want to spend the $$ on the system I normally use.....

You're doing 4 wheel discs, right?