mark69sportsroof

I finally got the mc off by pulling, yanking and anything else. I dented the shock tower right in front of the mc so I can get it off in less then 2 hours. I got my 5th mc from the local mustang shop who got it from O'Reilly's surprisingly enough. I'm at the point of I don't care as longs as it works. The brake boost push rod came out along with the rubber seal in the midst of the removal. I place a clean rag down inside the brake boost and no fluid on the rag, so I don't believe any brake fluid got inside. I will get a new rubber seal for the brake boost and try everything again. Thanks Mark

Thanks Brian, I am trying a new mc from the local mustang shop. How do I dry out the brake boost with paper towels? All I see is the gasket in the opening and the push rod. I don't know if the gasket can come out in order to get the paper towels inside to dry it out. Thanks again, Mark

Brian, thanks for the pics. I have the same measurements on the bolts and mc mounting bracket. Can you measure the mc unit itself. I believe mine is 7 1/4 inches. Also can you estimate the distant from the front end of the mc to your shock tower. I checked the mc I got from NAPA and it's the same one you have the M1929. All three have leaked from the back. They are made byUnited and made in the U.S. NAPA manager said if it leaked again he would change manufacturer. I will stop by in the morning to discuss it with him. Thanks Mark

I still can't get the mc off. Even pulling it up and toward the engine the mc will not come off. I checked the brake boost 2 bolts and both are snug. The front of the mc hits the shock tower when trying to pull it off. The driver side of the mc moves to the end of the threads on the bolt, the passenger moves about half the distant. It's not hard to get in but hard to get off because of the shock tower and bolts. I thought about cutting the bolts off about 1/2". I can't get the brake boost off with the mc still on. Any tricks on getting the mc off? Can some one measure the bolts from the brake boost to the end of the bolts? I would like to verify their length. Thanks for your time and patience. Mark

Frustration is taking over. I got the 3rd new mc. Bench bled it and mounted it to the brake boost. I didn't hook up the two lines. I had two plastic tubes that I used to bleed it and I left them attached to the plastic plugs that screw into the mc. Reached up under the mc where it connect to the brake boost and got 3 fingers wet with brake fluid. How could that be since it was only mounted? I went to take off the mc and can't get it off. I pulled it toward the engine and upward but I can't get it pas the brake boost bolts. I wiggled and jiggled and nothing. I don't if the push rod is not going all the way back into the brake boost. I can barely see it when trying to get the mc off Thanks Mark

I don't know if any brake fluid has leaked into the brake boost. Is there an easy way to check?

I was wondering if the push rod that goes into the me is to long. When in place does the push rod go all the way into the mc? Or is there a space at the end the of the push rod and the inside of the mc. Thanks Mark

The brake boost and the mc appear to correct and no damage.

It's bolted down tight. It has to slide down the shock tower the last inch or so. I thought about trying to put a small dent in the shock tower to give it some room. Any other ideas? Thanks Mark

Removed the mc. This time it was a pain and fought me for an hour to get it off. Best I can tell the push rod was forward and getting in the way. Got the new one on but my questions is the front of the mc is hitting the shock tower. It looks basic level. Is the mc suppose to touch the shock tower? I'm thinking by hitting the shock tower and is slightly elevated might be causing the leak at the mc and brake boost. I measured the mc's and they measure 7 1/4" Thanks Mark

I was stopping the fluid flow while it was still coming out of the bleeder screw. Got the 3rd mc, will bench bleed and try again Mark

Another update - received a new (not rebuilt) mc from NAPA. I benched bled it using a tube kit and by the manufacturer instructions. Attached it the brake boost, attached the lines. Had my 83 year old mother in law doing the brake pedal. I did the correct sequence and had her pump it 4-5x and hold the pedal. Iopened the bleeder screw, pedal went to the floor. She held it there and I closed the bleeder screw. Then she released the pedalDid each brake 4-5x. Brake pedal seemed normal. I started the car and had about 50% at best. Drove it a few miles and checked for leaks. Once again it is slowly leaking on the bottom side of the mc where it attaches to the brake boost. Unbelieveable. I am picking up my 3rd mc from NAPA. The first mc didn't leak there but the last 2 from NAPA has. What should I check for on the mc or the brake boost to figure out why it's leaking? Thanks for you advice Mark

WOW, thanks for all the info. Let me try to answer all the questions. RMmach1 - I took off the MC again last night and cleaned the outside of it, remounted and just pumped the brakes and no leaks. Just checked it again and it was leaking again in the same spot. You are right - back to napa for a new mc. Brian - I have all new brake system from the local mustang store. I have a rebuilt Bendix 6945. I have the correct pedal setup, and the 68-69 reproduction (original style) proportional valve. Mach1Rider - the guy you rebuilt the brake booster and had the mc and measured the mc pushrod so it would be the correct length. Do I need to have it checked again that a have a new mc? RPM - I have a helper. Mother in law does the brake pedal, I do the tires Ridge Runner - I do 90% of what you said. I hook a rubber hose to the bleeder then loose it. I have the other person pump the brake pedal 3x slowly and on the last one hold the pedal to the floor. Then I tighten the bleeder. I do this 3x on each wheel. The difference is the hose in the bottle is not in the brake fluid to suck it back in. I must be sucking air back in the system. Sounds like I need the another new mc. Then bench bleed it. Bleed brakes with the additional step of the hose in the bottle submerged in the fluid. Thanks Mark

OK update. Took the mc off and had a local mechanic bench bled it. Put it back on the brake booster and tighten down and attached the two brake lines. Then I realized the engine bay electrical were between the mc and exhaust manifold. Took the 2 mounting bolts off the mc and pulled it forward and up to slide the wiring between the mc and shock tower. Tighten the 2 mounting bolts. I didn't disconnect the 2 brake lines. Checked all lines for leaks and no leaks. I'm not sure if the proportional valve is centered (I figured probably not) so I go the PS front brake and opened the bleeder and stomp on the brake pedal one time and retighten the bleeder screw. I also did the LR brakes the same way trying to re center the valve if it was off. Pedal pressure feels normal when the engine is off. So I start the engine and once again I lose pressure down to the floor. I have just enough to stop it going 10 mph and pumping the pedal. I drive 1/4 mile to get gas and notice I have a puddle under the MC area. Looking for the source I discover the mc to the brake boost is leaking underneath the mounting bolts. I take the mc off totally to clean it. Re mount the mc and re secure brake lines. No leaks. I bleed all brakes again in the sequence of RR, LR, FR and FL. The brake pedal does to the floor as before. Check MC and no leaks anywhere. Frustration level is rising. It has been 4 months fighting the brakes Thanks Mark

I k the mc off and bench bled it. It had a lot of bubbles. Re installed it and will bleed the brakes tomorrow when I have some help. Thanks Mark

I agreed. I have decided to pull the new mc and bench bleed it. On the brake light switch I'm confused on the pin situation as described by Ridge Runner? Please clarify. Thanks Mark

Thanks for all the help. This is new to me. I don't always have a second person to help so I try to do it in the vehicle. I will try again and keep you updated. Thanks Mark

Its from NAPA and the box says Premium New Master Cylinder. Before replacing the mc, the pedal had about 10% resistance and if you pumped it 2-3x it was about 70% pedal pressure. After installing the new mc, I have hard pedal pressure at about 2 inches moving to toward to the floor. It feels normal pressure. Then I start the car and the pedal goes to almost no pressure. I was reading the mc instructions and I believe I might have messed up. When I bled the MC in the car. I attached 2 old mc line to the mc and bent them to drain back into the mc. The instructions say to keep the lines submerged in the mc fluid so it doesn't suck air back into the mc. Any thoughts? Thanks Mark

I doubled check the calipers and they are mounted correctly as shown in the picture above on the left side. The pedal pressure has always been the same. The brake booster was rebuilt. The pedal has good foot pressure then when I start it no pressure. Thanks Mark

Everything is new on the brake system. it has about 70 miles total the car. Just got done with a 4.5 years restoration. I will bled again tomorrow and update all. Thanks Mark

I bled the mc in the car. After 45 minutes the front disc brake bowl would only dribble out. I put in a new mc and bled it again. Great fluid from the front and rear bowls. I bled all brakes and the brake pedal would be firm at 1-2 inches when pushing it down. Finally normal functioning brakes. I start the car and the pedal goes to the floor with about 10% pedal pressure. I noticed to 2 brake line connections barely dripping. I tighten them up. Any ideas on what to do next? Thanks Mark

Thanks for the info. When I remove the 2 existing mc lines will the fluid in the bowls drain out? Thanks Mark

Hey All, What is the best way to bleed the master cylinder when it's in my 69 Sportsroof. I have disc up front and drum in the rear? Thanks Mark

I use regular window screen. I cut it a little larger then the radiator core opening. I then use 5 black butterfly paperclips. I use 2 on the top and 3 attached to the bottom on the core opening. Takes less then 30 seconds to put on or off. Keeps my radiator brand new looking and no bugs. It really stands out. Mark

Yes, it's a diaphragm clutch quick release. The pedal doesn't have any play. The clutch does work but doesn't dis engage. I talked to McLeod Clutches today and they say the bearing travel is 1/2". Modern Driveline says what I must have is 3/8" - 7/16" bearing travel max. McLeod says they can take off some "marcel" ( what ever that is) to meet the 3/8" - 7/16" bearing travel. So I am sending then the clutch and pressure plate to make the adjustment. Modern Driveline says I can leave the clutch as is but would have to switch to the hydraulic setup. That way out of my budget. Thanks Mark