Rebuilding Brake Master Cylinder... Stuck

Joined
Oct 14, 2009
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80
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Hoquiam, Wa
I'm stuck on the secondary valve. Everything came apart REALLY easily. I snapped one of the brake lines, but I have a buddy with a flare tool to help out tomorrow.

I got the snap ring off, and everything pretty much jumped out of the master cylinder... except the secondary valve. How do you get that out? It feels like there would be a second snap ring inside the cylinder, the way it keeps returning to the exact same spot and stopping so abruptly, but I can't see one. Is there a trick to getting this removed? Don't have air, or I would have tried blowing it out. It moves really easily inside, and everything looks great. What am I missing?


It's a '76 fj40. Maybe time to just order a new master cylinder. It was 7 days out. I thought I could rebuild it quicker. :doh:
 
Joined
Sep 3, 2007
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My master has a little screw/bolt on the side (that a 10mm spanner fits if I recall correctly) and before removing anything (other than the circlip) you push in the outer piston (which I use a phillips-head screwdriver to do) and then unscrew that bolt.

With the bolt out ... the whole sheebang/innards will come out easily.

And when you reinsert the pistons and springs - you push them in (using the screwdriver technique again) before reinserting the screw/bolt.

That screw/bolt prevents the front piston and spring from being removed.

:cheers:
 
Joined
Oct 14, 2009
Messages
80
Location
Hoquiam, Wa
Thanks again. Worked great. Got the bolt off, and after fiddling with it for a few minutes, it came right out. Broke one of the lines when I was taking it off, and the flare tool we had was SAE. It sucked. Still need to flare out the line, and my buddy is searching his friends' tool boxes for the right, or better one. 3 days for a 1 hour job = yay.

Without searching, just wondering what would be the best aftermarket MC to buy. I found a site with a few of them, but wanted to know what others were using. I'll go search, but all I do is search and find the answer I'm looking for, and I'm never involved in a proper discussion. We rebuilt this one, but it was really pitted inside. I'll be ordering this Friday.

Thanks again.
 
Joined
Jul 26, 2010
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Do you remember if the heavier of the 2 springs goes in the middle or in first ?? I am rebuilding mine and I think I didn"t do it right along time ago .
Carlos
 
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Do you remember if the heavier of the 2 springs goes in the middle or in first ?? I am rebuilding mine and I think I didn"t do it right along time ago .
Carlos

Looking at a line-drawing of mine I was going to say that the front one looks longer:

mastersprings1.jpg

But then when I look at other images (from microfiche), they look the same size:

masterspings2.jpg

So .... I can't say. But if it worked well as it was, I wouldn't worry about it. (ie. Reassemble it the same way.)

Was the longer one to the front or rear? (or is one actually of thicker spring wire than the other?)

:beer:
mastersprings1.jpg
masterspings2.jpg
 
Last edited:
Joined
Sep 3, 2007
Messages
8,871
Location
New Zealand
the springs are very similar except one is way heavier than the other :frown:

I should have realised.... Look no further than Coolerman!

Master Cylinder Rebuild

P1100006.jpg

:cheers:

PS. Since they are of different gauges/strengths, getting them the wrong way around would indeed be very bad! But I suspect they're unlikely to fit properly when reversed. So my quess is that you (Whitethunderx) actually got it right the first time.)
P1100006.jpg
 
Joined
Jul 26, 2010
Messages
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That make sense that the lighter spring be in the middle , so that the stronger spring disengages the front brakes better and reversed would more than likely cause brake lock up ( too easy to press all the way down ) thxs again !!:clap:
 

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