1969 FJ40 and JT extension for brake booster fitting

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Oct 31, 2008
Napa Valley California
Picture says it all. Am I ok with just using some washers for spacers on this or should I build a spacer to match JT's bracket. I placed a couple of small washers on one side just to see how much it helped. I could also just add some bigger washers on one side.
I would hate to cut out any of my cowl to fix this issue. If you notice I also ground down part of the 3 hole side of the extension to fit the cowl. I painted it with Silver Hammer paint to make it look pretty as well.
Booster extension1.jpg
Booster extension.jpg
Booster extension2.jpg
Why not space the entire assembly out at the firewall where the spacer mounts? If I was in that situation that's what I'd do. If I had designed that piece I would've made it a 1/4 inch longer in the first place. My personal solution was redrill my firewall and not run a booster on my '63 and my '69 has dual wilwood master cylinders on the shelf waiting.
Space it out from the 4 hole side. You can see that the ridge on the cowl will not let the JT extension make it any bigger. I would just furrow it out from inside of the rib.
If you spaced it enough with washers or cut a spacer from 1/4 plate (I like to give a decent gap), used longer bolts, and fed it from the front then the rib would not be an issue as the tubular portion and mounting studs for the booster look like they would clear fine. Or, if you're handy with a welder, get a section of tubing the same size as the JT piece and splice it in the center. Using washers at the booster doesn't sit well with me just because I wouldn't do it myself, I'd spend more time reworking the damn thing and wondering why I didn't make one in the first place.
As you can see the rib is very thick since I had it coated with bed liner. I think I will use my dremel and grind off some of the armacoat so that a 1/4 inch plate will fit as a spacer. I will post picture after I get some of the armacoat removed.
I have been thinking about this, especially since no one else has chimed in on what to do. I can either use a couple of big washers or build out a metal 3/16 spacer. The other option would be to make a 1/4 inch rubber gasket. What do you think?
If 3/16 would give adequate clearance the metal spacer at the firewall would be my first choice, washers second, rubber gasket third. I'd just worry about the rubber compressing over time or degrading.
Problem Solved!! I think

I cut back the Armacoat on the ridge of the engine compartment to the metal. Then I used stainless washers to shim the booster to JT extender. I actually cut about 1/3 of the washers next to the ridge in order for them to sit flush with the washers on the other side. Here are my pics.
Booster solved 1.jpg
Booster solved 2.jpg
Nice work mcwinery,I just saw this thread.I also used thin washers for my booster to clear adapter with that rib right there.
Hows it looking for your carb. fitment? It will be a close/tight fit wit the MC!!
Glad you got it to work...looks good :beer:

I was just going to suggest getting in touch with Mark, as I believe his booster spacer does not have this issue. I was looking for a picture of one of his mounted, but could not find one...maybe Mark can chime in with a picture for future reference :idea:
FWIW, I installed Mark's adapter and did not have this issue.
I think the issue is what year FJ you have. Mine is just a ridge is just a little longer than others. The other option I could have taken was to extend it out from the firewall but then I would have needed at least 1/4 inch more to clear the plate from ridge.

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