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I am having an issue with a dual bowl master cylinder conversion from CJ Mustang that I installed today. My brake pedal is now about 1" lower than it was before. I have to push it about 1/2 way to the floor before I get a pedal. I used my old pushrod because it was about an inch longer than the one that came with the master cylinder. I have bled the brakes twice and the pedal is no better. Anyone have any ideas? Im at a loss...
 

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Usually those come with an adjustable push rod.
 

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The one I got from Cj's had an adjustable push rod. A slight difference in push rod length will make a big difference in pedal height. Ger one of these: https://www.npdlink.com/product/pus...cylinder%2Bpush%2Brod&top_parent=200001&year=

There are some very bright people in here that should chime in on brakes.

I have front disks and rear drums and I thought my pedal was atrocious and the car didn't stop well. I did the booster thing and less pedal pressure but still not that good. Turns out my drums were shot. Now after new drums, the car stops fine and the pedal feels solid.

Work your way from MC back and check for leaks. What is your set up? Disk front and drums rear?
 

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Discussion Starter #6
I have a drum/drum setup. I had to destroy the piston in my old master cylinder to remove the pushrod so, I dont know how deep the bore on the old one was to compare. How do you determine the correct push rod length ? Right now, if I disconnect the pushrod from the brake pedal, it is seated in the bottom of the bore on the MS and lines up with the brake pedal shaft. It seems more like the MS is not effective until the piston is depressed at least 1/2". Ive been working on cars all of my life but this one has me scratching my head.......
 

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Yes I did but I plan on pulling it tomorrow morning and doing it again..just in case......

Why don't you do it with it mounted in the car? It's the same thing. And FWIW I've never bench bled one. I install it, connect it and do a 2 man bleed. The whole purpose is to get the air out, however you choose to do so.
 

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Also make sure the pushrod isn't too LONG. If it won't let the master cylinder piston return all the way to the "rest" position it may not be allowing the uncovering of the equalization port(s).
 

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I had the same issues as many above when I converted to front disc and dual bowl master cylinder. I bled and bled them and could not get pedal. I then made an adjustable pushrod and now I have good pedal and brakes. I adjusted my pushrod by making changes in it's length and then pushing on the car to guage resistance/drag. When I got it where I wanted it I tightened up a lock nut against the coupler.
 

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Some of this is repetitious and others have mentioned already....

"Pedal" bleeding is all technique. Sometimes you have to vary what you're doing to free up
air bubbles. (short staccato pumps) I played games with one a few years ago that was a real
PITA. Took about a half hour to get the pedal perfect...... and keep in mind I've been doing
brake work 40+ years.
The other details for the OP's situation- static pedal height.... try to keep that around the height
of the clutch pedal (if fitted) or at the original height of the brake pedal before it was fooled with.
Rear drums need to be adjusted correctly to get a decent brake pedal. They can't be miles away
from the drum surface or the drums massively oversized.
Leaks. The smallest leak will guarantee a crappy brake pedal.
Internally bypassing "BRAND NEW" master cylinder. You will never "get a pedal."
Wish I had a buck for all those I've seen in 40+ years. Way more warranty on those parts
right out-of-the-box then you would think. I wouldn't touch a re-manufactured one either.
Generally complete junk.
If you over-extend a piston inside a master cylinder, (like when you're manually bleeding it), you
can damage some masters that way. You will never "get a pedal."

I'm in the no bench bleeding camp. Didn't do it at JBA, didn't do it at Global. Never done it at home.
Complete waste of time.

ex-Global West GM
1991-1995
 

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"Usually those come with an adjustable push rod. "

That all depends on what kit you buy.

You are supposed to re-use your Original Pushrod...Not chuck it out... and "NOT USE" the one that comes with the kit because it's to short. If you don't have an Original Pushrod, Just buy an adjustable one...as pictured and mentioned above.

:eek:)

Tony K.
 

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I'm in the no bench bleeding camp. Didn't do it at JBA, didn't do it at Global. Never done it at home.
Complete waste of time.

ex-Global West GM
1991-1995
I stopped bench bleeding when I got the Motive pressure bleeder. It even lets me bleed through the ABS on my newer stuff with the proper M/C adapters. You do have to cycle the pedal while under pressure to get the air out.

https://www.amazon.com/Motive-Products-105-System-Bleeder/dp/B00CJ5DY16/ref=pd_day0_hl_263_2/140-0987811-0032031?_encoding=UTF8&pd_rd_i=B00CJ5DY16&pd_rd_r=bcb201f0-e5a6-4cb6-bc97-3aa3215ffed8&pd_rd_w=NiH4Y&pd_rd_wg=H8kNh&pf_rd_p=ad07871c-e646-4161-82c7-5ed0d4c85b07&pf_rd_r=6AR2ATT2NRDTGR3CS7RS&psc=1&refRID=6AR2ATT2NRDTGR3CS7RS
Forget about the hokey chains and such in the kit and use a 6" C-clamp to hold the bleeder cap on the MC.
 

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"Usually those come with an adjustable push rod. "

That all depends on what kit you buy.

You are supposed to re-use your Original Pushrod...Not chuck it out... and "NOT USE" the one that comes with the kit because it's to short. If you don't have an Original Pushrod, Just buy an adjustable one...as pictured and mentioned above.

:eek:)

Tony K.
So if CJ's is selling a "kit" that includes something you shouldn't use and doesn't include something you should use, adjustable push rod, Isn't that the definition of a crappy "kit"?
 
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"So if CJ's is selling a "kit" that includes something you shouldn't use and doesn't include something you should use, adjustable push rod, Isn't that the definition of a crappy "kit"?"

No, Not really.... The reason is because the majority or "Re-built" and even "NEW" Dual Bowl Stock Master Cylinders from most companies (That Make or Rebuild them) include a Pushrod already in the box... The only problem is that its usually too short for certain Mustang applications. CJ's or any other Mustang Vendor has absolutely nothing to do with it... It has to do with the "Rebuilders" and the makers of "NEW" Stock Master Cylinders out there. It's also because the same Master cylinder covers a wide spectrum of different Ford Car models over a span of different years...let's say from the Late 1960's to the Early 1980's for example. ('67-'83) for instance.

:eek:)

Tony K.
 

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"So if CJ's is selling a "kit" that includes something you shouldn't use and doesn't include something you should use, adjustable push rod, Isn't that the definition of a crappy "kit"?"

No, Not really.... The reason is because the majority or "Re-built" and even "NEW" Dual Bowl Stock Master Cylinders from most companies (That Make or Rebuild them) include a Pushrod already in the box... The only problem is that its usually too short for certain Mustang applications. CJ's or any other Mustang Vendor has absolutely nothing to do with it... It has to do with the "Rebuilders" and the makers of "NEW" Stock Master Cylinders out there. It's also because the same Master cylinder covers a wide spectrum of different Ford Car models over a span of different years...let's say from the Late 1960's to the Early 1980's for example. ('67-'83) for instance.

:eek:)

Tony K.
Fair enough. If I was the vendor I would have removed the wrong push rod and included an adjustable one with instructions considering the price they charge compared to other venders. It would probably help with customer retention long term. I gave up on them years ago.
 
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