Different master cylinder

[wrshog]

The valve covers on my engine are too tall and wide to get off and I had to grind some material off the mc so it wouldn't rub. To get the current mc out I am going to have to cut it out. Has any one used a different master cylinder in there Mustang? Mine is a 1971 front disc rear drum. I was thinking that one from Bronco II might work as it is narrower than the one I currently have. Other option is to get new valve covers but I still have to cut this mc out to get the current valve covers off. ughh this car has fought me every step of the way....

 

[will e]

Pictures? What engine do you have? If it is close enough to rub it will probably hit it under accelleration. If it isn't hitting I would just remove the MC whenever I needed to take the valve covers off.

 

[wrshog]

Pictures? What engine do you have? If it is close enough to rub it will probably hit it under accelleration. If it isn't hitting I would just remove the MC whenever I needed to take the valve covers off.

Problem is I can't get the mc off without cutting it out...... I ground some of the mc material down where it was rubbing but still. It's an issue I eventually have to deal with. I finally was able to get some mounting dimensions from a parts store and it appears that the 88 Bronco II mc will mount to my booster. I ordered one in and will give it a try. Now I just have to figure out how to get the current mc cut out of there. MC's are far less expensive than valve covers so this is what I have chosen to do.

It's a big block engine.

 

[will e]

Okay, I understand now. With the valve covers on you can't slip the MC off.

 

[Don C]

Have you looked at hydroboost? The power brake boost is provided by the power steering pump, doing away with the vacuum booster can.

I'm like will e, I don't understand why you have to cut out the MC. It had to be installed some way.

 

[wrshog]

Have you looked at hydroboost? The power brake boost is provided by the power steering pump, doing away with the vacuum booster can.

I'm like will e, I don't understand why you have to cut out the MC. It had to be installed some way.

The mc was mounted when we put the engine back in. It hit the MC going in so we loosened the mc and it rubbed its way by as it went in. Once the engine was in we could not re-tighten the mc cause it hit the valve cover so I took a large cut of wheel on a drill and just removed some material from the mc so it didn't hit anymore. The inside bolt on the brake booster was about 1/4" from the back of the valve cover and the mc covers the back bolt for the valve cover.

 

[Don C]

Do you have power brakes? Can you loosen the booster from inside, under the dash?

 

[will e]

The hydroboost suggestion might be a good option. Gotta stop that big block bad boy somehow!

 

[JimNiki]

Undoing the engine mounts and jacking up the engine 2 inches won't help?

 

[wrshog]

Undoing the engine mounts and jacking up the engine 2 inches won't help?

Thanks for all the suggestions but the only two options were to pull the engine or cut the mc out. We did loosen the booster but that gave us nothing.

I cut the mc out yesterday and bolted in the new one which is for an 88 Bronco II. I had to cut about 3/8" off the mounting bolt behind the valve cover to get the mounting ear out that I had cut off. The bolt was that close to the valve cover. Just made some bad decisions when it came to valve covers.

The mc slid in with no real issues and has the same mounting bolt locations. I did have to adjust the booster push rod out about 1/8". It has different size line connectors but they were available at the local napa and so I just reflared the lines and voula.

The proportioning valve was of course blocking the flow to the rears but a guy at the auto parts store gave me advice on how to reposition it and it worked great. I opened the bleeder screw on the passenger front, pushed the brake pedal slowly until I felt and heard a "click" and the rears started flowing. Pretty slick.

 

[wrshog]

Pictures? What engine do you have? If it is close enough to rub it will probably hit it under accelleration. If it isn't hitting I would just remove the MC whenever I needed to take the valve covers off.

Here are some pics of what I am talking about

 

[will e]

WOW that is tight! I am glad you figured out a solution. Engine looks good.

 

[73vertproject]

WOW that is tight! I am glad you figured out a solution. Engine looks good.

+1!

 

[MechEng]

Dang that's tight! Looks mean though. Good to know that a Bronco II booster is nearly drop in. I really like having the clear bowl for checking fluid level.

NPD Sells a little screw that goes into the distribution block where the brake light switch goes to hold the little slider in the center while you bleed your brakes, otherwise you can fight it quite a bit!

 

[wrshog]

WOW that is tight! I am glad you figured out a solution. Engine looks good.

Thanks I think it looks pretty good too just wish I were done with it and had good weather for driving. Engine ended up coming out as a 547 ci torque beast. Took it for a couple short spins and I look a bit silly with the top down and 3' snow banks all around me. But she definitely hauls @$$! Now I just need to finish up the brakes so I can stop it. Currently dealing with a low pedal before she grabs......

Then some traction bars and my GW subframe connectors.

 

[Thomas]

HI !

I Have just installed a Bronco II Mc on my 71, but my push rod in the booster was flat in the end, While Broncos MC requires a push rod with a ball on the end. Did you also have problems with that or is your booster newer? Know that the 73 model year have the ball on the push rod end.

(I cut my push rod so I got a round end on it)

// Thomas

 

[wrshog]

HI !

I Have just installed a Bronco II Mc on my 71, but my push rod in the booster was flat in the end, While Broncos MC requires a push rod with a ball on the end. Did you also have problems with that or is your booster newer? Know that the 73 model year have the ball on the push rod end.

(I cut my push rod so I got a round end on it)

// Thomas

I had replaced the booster with a new one and it had a rounded end, actually like a cap nut on the end. I had no problems but that's good info.

 

[Thomas]

I must take this opportunity to thank for the tip about the Bronco II MC!

I've been looking for an MC who could fit, my problem was that the brake fluid reservoir on the original master cylinder was too large so the valve cover could not get into position. But all MC I've found have had the brake pipes exit on the wrong side ( RH ). I had begun to modify an original master cylinder. But now I did not have to do it. So thank you very much for the tip!

/ / Thomas

 

[wrshog]

I must take this opportunity to thank for the tip about the Bronco II MC!

I've been looking for an MC who could fit, my problem was that the brake fluid reservoir on the original master cylinder was too large so the valve cover could not get into position. But all MC I've found have had the brake pipes exit on the wrong side ( RH ). I had begun to modify an original master cylinder. But now I did not have to do it. So thank you very much for the tip!

/ / Thomas

Holy $#!+ now that is a modification....... I've taken so much from this site I am glad I was finally able to give a little something back.