Ford Mustang Forum banner
1 - 12 of 12 Posts

·
Registered
Joined
·
503 Posts
Discussion Starter · #1 ·
Hey guys,

So I bought a disc brake setup that a guy had bought from MustangsUnlimited. I'm not sure where he got the dual bowl master cylinder or brake booster, but they appear used. I got the booster/MC hooked up to my car but the lines kept pumping out air no matter how much we bled them. Thinking it was the master cylinder, I bought a new one from RockAuto... its a dual bowl Raybestos model.

The problem is that after hooking it up, it appear the booster doesn't engage the MC...when I pump the pedal the fluid in the reservoirs doesnt even move. I bench bled the MC as soon as I got it out of the box. Is there anything I can do to fix this or do I need to buy a matching booster??

THanks guys
 

·
Registered
Joined
·
1,275 Posts
Hey guys,

So I bought a disc brake setup that a guy had bought from MustangsUnlimited. I'm not sure where he got the dual bowl master cylinder or brake booster, but they appear used. I got the booster/MC hooked up to my car but the lines kept pumping out air no matter how much we bled them. Thinking it was the master cylinder, I bought a new one from RockAuto... its a dual bowl Raybestos model.

The problem is that after hooking it up, it appear the booster doesn't engage the MC...when I pump the pedal the fluid in the reservoirs doesnt even move. I bench bled the MC as soon as I got it out of the box. Is there anything I can do to fix this or do I need to buy a matching booster??

THanks guys
The rod that sticks out of the booster & pushes the master cylinder can be adjusted by turning the nut, it might be too far in to engage the master cylinder. It's not hard to adjust but it is time consuming to get it perfect.
 

·
Registered
Joined
·
503 Posts
Discussion Starter · #3 ·
Where is the nut located?? on the rod that sticks out of the booster where the MC would go? or the pushrod part inside the car?

thanks alot man
 

·
Registered
Joined
·
1,275 Posts
Where is the nut located?? on the rod that sticks out of the booster where the MC would go? or the pushrod part inside the car?

thanks alot man
"The rod that sticks out of the booster & pushes the master cylinder can be adjusted by turning the nut"

Here is a pic of what I am talking about (this one is from a 70's Granada but the general idea is the same):

 

·
Registered
Joined
·
503 Posts
Discussion Starter · #5 ·
Okay so I extended the screw out about an inch so now it contacts the plunger inside the master cylinder. how far does it have to push it?

right now I think it's only pushing it 1/4" at most from my measurements.
 

·
Registered
Joined
·
1,275 Posts
Okay so I extended the screw out about an inch so now it contacts the plunger inside the master cylinder. how far does it have to push it?

right now I think it's only pushing it 1/4" at most from my measurements.
Your goal is for it to ALMOST touch when it's all tightened down, but not quite. That way only the brake pedal pushes the master cylinder.
 

·
Registered
Joined
·
913 Posts
The rod that sticks out of the booster & pushes the master cylinder can be adjusted by turning the nut, it might be too far in to engage the master cylinder. It's not hard to adjust but it is time consuming to get it perfect.
Not if you have the right tool, then it only takes a few seconds.
 

Attachments

·
Registered
Joined
·
1,275 Posts
Not if you have the right tool, then it only takes a few seconds.
Wow thats awesome I wish I could "LIKE" stuff on here, lol. Yeah that would have made my job much easier because it's pretty difficult to measure otherwise.
 

·
Registered
Joined
·
503 Posts
Discussion Starter · #9 ·
Ahhh okay thanks Cracker. I think my screw might be too short... the plunger inside the MC sits about 1 1/2" inside and right now the screw sticks out about 1" or 1 1/4"

this may be a dumb question but could you fabricate your own screw a little longer than the stock one?
 

·
Registered
Joined
·
1,275 Posts
Ahhh okay thanks Cracker. I think my screw might be too short... the plunger inside the MC sits about 1 1/2" inside and right now the screw sticks out about 1" or 1 1/4"

this may be a dumb question but could you fabricate your own screw a little longer than the stock one?
On the one I showed you, if I pull it out it's got a cylinder attached to it, so I don't see how I could extend it, unless I found another one with a cylinder of the same diameter to exchange it with.

Do you have the right master cylinder (I apologize if that question was already asked or answered I don't recall seeing it)
 

·
Registered
Joined
·
503 Posts
Discussion Starter · #11 ·
yeah mine has the cylinder your talking about but I wouldnt swap the cylinder... i just thought i could swap out the screw that threads into it that contacts the master cylinder that way it can be longer

I was unsure what year the master cylinder/brake booster combo was from because I bought it used from a guy... so I ordered the new master cylinder for a 67 mustang

The difference is that the plunger inside the new one sits 1.5" inside whereas the one that was originally on it sits right at the edge
 

·
Registered
Joined
·
1,275 Posts
Well I think you got it all figured out then and when you get your new parts, hopefully everything will work right!
 
1 - 12 of 12 Posts
Top