1G Adjust 3g MC on stock Brake Booster?

[James92]

Quick question, I installed a 3g master on a stock brake booster and all seems well but before I consider this finished I wanted to consult on the adjustment portion of the Brake Booster rod to the MC. Is this even adjustable? It’s installed and didn’t want to remove it and find out it’s not or maybe they’re well paired as is.

I also stumbled upon using the 1g reservoir on the 3g MC and wondering how reliable that is, it’s currently close to my strut tower bar but not touching but wondering if that’s a move I should make too.

Thanks

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[BaltFan001]

I have a similar setup on my 1g, I swapped over the 1g reservoir and rubber plugs that were in the original MC onto the 3g, so far, I haven't had any issues. As for the adjustment I did use a small probe to check how much relief the pushrod in the brake booster had before throwing on the 3g MC just to be safe, I took the 3g MC off of well-kept car when it ended up in the junk yard and I measured the gap with the probe as just about .5mm which I thought was fine, so I didn't need to mess with it. The big thing I found out about leaking though is that the 1g DSM lines to the master cylinder have inverted flare fittings, whereas the 3gs are bubble flare, so to be on the safe side I used bubble flare to inverted flare adapters to be 100% sure nothing would leak. I've heard guys say that they've been fine without adapting the threads though so just check up on it now and then to make sure they seal up fine.

 

[James92]

I have a similar setup on my 1g, I swapped over the 1g reservoir and rubber plugs that were in the original MC onto the 3g, so far, I haven't had any issues. As for the adjustment I did use a small probe to check how much relief the pushrod in the brake booster had before throwing on the 3g MC just to be safe, I took the 3g MC off of well-kept car when it ended up in the junk yard and I measured the gap with the probe as just about .5mm which I thought was fine, so I didn't need to mess with it. The big thing I found out about leaking though is that the 1g DSM lines to the master cylinder have inverted flare fittings, whereas the 3gs are bubble flare, so to be on the safe side I used bubble flare to inverted flare adapters to be 100% sure nothing would leak. I've heard guys say that they've been fine without adapting the threads though so just check up on it now and then to make sure they seal up fine.

Thanks for all that; I ended up just putting the inverted lines in and seeing how that goes, I too have heard others not having any problems so for the sake of it all I just jammed them in and haven’t seen any leaks yet however it doesn’t get driven very often as it is a “weekend” car but I have toyed with an fittings and braided lines and seems like the fittings alone are expensive and will keep that in the back pocket if I ever get bored with something on the car.

I also would prefer to keep the 1g reservoir except the cap doesn’t make a very good seal and ends up skipping loose once it begins to tighten, may need to test the 3g cap and see and if it works then I’ll switch back to the 1g res.

.5 isn’t bad, my pedal feels pretty good so it’s probably about the same as yours, I did pick up one of those tools for measuring the depth of the mc against the push rod just for fun; it’s $7. I can report back on what I find as far as gap since I haven’t changed the push rod at all.

I’ve never messed with brake stuff before and so far I’ve learned a lot, I’ve rebuilt both rear calipers, changed to SS braided lines, new rotors, never bled a brake system before so once I installed the the new MC I learned there’s a tool to measure the relief gap and dug around a little more and found that I did not do that, got me thinking maybe I don’t need to worry about it much because no one else had mentioned it when discussing 3g master upgrade.

So I’ll check the adjustment rod, my cap fitment and if that’s good I’ll swap over to the 1g res. I appreciate your feedback, gave some things to think about.

 

[BaltFan001]

Any time, glad I could help.