Ok the pictures posted all weird, but I am having some issues with my master cylinder swap, even after reading the various threads & watching the YouTube videos. And yes, I did bench bleed the MC before installing it. After swapping my MC to the new one, the car stops, but my pedal has too much "free play" before actually moving the MC piston at all. Once the MC piston starts moving the brakes also apply quickly and maybe a little too firmly. It's like there's an inch of travel where absolutely nothing happens, then about one more inch of pedal travel while the brakes apply, then the brakes are fully applied. Also, the excess freeplay causes the pedal to not return completely. Like it has a dead spot when you release the pedal and this causes the mechanical brake switch to stick "on" sometimes because the pedal hasn't returned quite all the way. It comes back almost all the way, and the brakes release fully, but the pedal doesn't push quite all the way back where it should. I used the same pushrod that was on the original MC (the top one in the picture of the two MC pushrods. The bottom one is the one that came with the mustang MC). I also found a rubber spacer between the piston & pushrod on the original MC so that was swapped over with the pushrod as well. (spacer is the little black thing in my hand in the picture). So here's where it gets super confusing. I checked the piston depth on the new MC and it's actually LESS deep than the old one, yet somehow I have too much freeplay?! So now I have no idea what the hell is going on. The picture of the pushrod with the 2 lines marked on it shows the difference in the piston depths. So, here's my list of questions. What pushrod did you guys use successfully, and does your pedal feel different? Does my pushrod look like the original or has it been switched out prior to me owning it? Is that rubber spacer original or was that something someone added later? Can I just use a longer pushrod to take up the freeplay or does that affect the pedal ratio? Sorry for the long post but I'm thoroughly confused....
Phaeton did yours look like the one in my picture and did it have a rubber spacer in between the pushrod and the MC?
It is impossible to tell from here but is the rod adjusted too short and the pedal needs to move an inch before the rod even contacts the piston in the m/cyl? If the m/cyl had full contact right from the get go then you need to keep bleeding those brakes because there is air in their somewhere.
It seems like the pushrod is too short, but it's the same pushrod that worked fine on the old one. I'm tempted to try a longer pushrod but I've heard that it screws up the pedal ratio and makes the brakes act funny when you do that. I don't think it's air in the system because the pedal gets very firm and stays firm. It just feels like the pushrod isn't touching the piston until you push the pedal down quite a ways. Hard to explain I guess. Is it safe to try a longer pushrod and see what happens?
After looking around online a bit I'm starting to think maybe someone put the wrong pushrod in my car. If you look at the pictures, the one that was on the car has a threaded end that just sits in the MC which doesn't seem right. Also I can't imagine that the rubber spacer is supposed to be in there. I think I may either get a new stock pushrod or try an adjustable one. Does anyone have a pic of their stock MC pushrod? A length measurement would help too if possible.
This has come up before,what you think appears to be threads on the original push rod are not threads at all and someone has added the spacer.The grooves on the end of the push rod at one time had a plastic tip which over time usually falls apart into nothing, to replace the tip on mine I found a plastic vacuum cap and lubed the end with a small dab of white grease. The push rod is the original one,not sure why you have the slack in yours unless the internal piston is different which is possible but I noticed you bought a "new" master which I don't recommend as many of the rebuilt masters are original USA made Bendix unit cores.
Thanks Jeff that's helpful, I was wondering what was up with that weird spacer. I thought buying a new MC would be better than a remanufactured one but I guess not. If this one goes out I'll pick up a reman version to replace it
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