1969 fj40 master cylinder for front disc brake conversion (1 Viewer)

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I have put a front brake disc conversion on my 1969 fj 40. The kit came from jtoutfitters. Everything fits right but I cannot find the correct master cylinder. The 70-75 Mc doesn’t work. Any suggestions?
 
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What do you mean by "doesn't work"?

More detail is required.
If fits but there is no brakes. And yes, I have bled the whole system many times. Regular, backward, and pressure bled...still no brake pressure. I have used the gap tool on the booster push rod also.
 

pjohnson

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If there is no air in the system, the only thing left is not enough throw against the master cylinder plunger. This points to the brake pedal throw or the pushrod length.

My experience is it probably is both since without sufficient movent of the master cylinder plunger, the air can't be completely removed.

Do you bench bleed the master before install?
 
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If there is no air in the system, the only thing left is not enough throw against the master cylinder plunger. This points to the brake pedal throw or the pushrod length.

My experience is it probably is both since without sufficient movent of the master cylinder plunger, the air can't be completely removed.

Do you bench bleed the master before install?
Yes. I did bench bleed. The booster is the recommended one from cityracer. The brake pedal is stock.
 
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Rod between booster and master is the next logical possibility.
I adjusted the length of the push rod coming from the booster with the recommended gauge. I think there is not enough pressure on the mc also. Is there a special master cylinder for this conversion?
 
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How much rod/threads are still available for adjustment? The pedal goes to the floor? Are you able to pump the pedal to obtain some or any pressure? Engine on or off?
I reckon if you totally give up then haul it down to Marks in Burbank
 

bulldog77

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I used the ADVICS BMT-090 for an 80 series when I converted the front to disc on my 1970. I'm not running a booster and the brakes feel pretty good.
 

3_puppies

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how about some pics of your setup?
69 should have been a single circuit system.
how is the booster mounted?
you could have went unboosted
the 70-75 brake master was for dual drums, the front residual valve would need to be removed.
lots of questions that need answers
 
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@Rambo19 - I just did a 4 wheel disc conversion on my 66. The pushrod is long enough to deal with the 1" adapter I used to convert from a 3 hole to a 4 hole master cylinder however...

Does the 69 still have the support rib that goes up the firewall between the MC and the Clutch master? Did you use a bracket to move the booster away from the firewall to clear that rib? If so, your OEM pushrod is not going to be long enough and you will need to install a longer one to take up the extra distance of the bracket. The booster bracket distance is too much for the pushrod to make up. Hope this helps.

Bill - IRB, FL
 

Rigger

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Did you use a bracket to move the booster away from the firewall to clear that rib? If so, your OEM pushrod is not going to be long enough and you will need to install a longer one to take up the extra distance of the bracket.

This.
 

Rigger

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@Rambo19

Have a look thru this thread:

 

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