Having trouble with operation of master cylinder. Resleeved with stainless, bore measures exactly .875" at opening. Used rebuild kit from major supplier. When blleding system - all new lines and silicone fluid - much less than normal amount of fluid would be expelled from each wheel cylinder. Took line off master cylinder and cycled pedal. First pump sent normal amount of fluid, but next and subsequent pumps sent little or nothing. Removed master cylinder from car and emptied reservoir. Watched opening in bottom to see action of piston. Pushed piston forward and it did not return immediately every time, sometimes it hung up, explaining why one pump would send fluid through system but not the next. If I waited a while the piston would return to normal retracted position. Disassembled cylinder, everything looked OK. Have ordered another rebuild kit, this time from the local NAPA dealer. Anyone have a similar experience? Is the secondary cup too tight, not allowing free return movement? Should the cylinder be honed slightly undersize to accomodate the seals? Thank you.
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Re: 63 Master Cylinder
Rick, Napa's, etc. rebuild kits do not come with a spring anymore. I assume you installed the old original long spring? John -
Re: 63 Master Cylinder
Used the original spring. Any alternatives? Do you think the spring is too weak to return the piston, or are the seals too tight for the bore. Can the spring be stretched?Comment
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Re: 63 Master Cylinder
Hi Rick,Don't stretch the spring. Wait until the boys get on to help you out. It's too late for the old senior citizens.
Whose kit did you use. EIS??? We had no problem at all. Oops. WE used a Wagner kit that I bought a while ago. THe EIS was a stripped down kit and didn't have squat in it. The Wagner had everything. Good nite, JohnComment
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Re: 63 Master Cylinder
Did you remember to put in the solid rubber cushion at the bottom of the bore? Did the sleeve installer remember to drill the 2 refill holes?Comment
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Re: 63 Master Cylinder
Yes to both questions. Rubber washer in bottom, holes are clear. Will be picking up new kit from NAPA in an hour. The present kit came from Paragon.Comment
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Re: 63 Master Cylinder
Picked up NAPA rebuild kit this morning. The Paragon kit is the exact same kit as the plastic bag has the same part number label on it. Cleaned the cylinder with denatured alcohol and assembled the kit with silicon brake fluid. Installed cylinder, checked rod clearance, bled cylinder in the car, attached main line and bled each wheel cylinder. High firm pedal. Appointment for alignment tomorrow. Car should be on the road this weekend, after sitting for 29 years. Thanks for you help.Comment
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Re: 63 Master Cylinder
Rick, Glad you are getting your car on the road after 29 years. My 63 sat about 15 years or more between restorations. I had lost interest in the car and it was the DB here and my son that got me interested again.
Meanwhile around 1980 when the car was first restored we used the silicon brake fluid. Lucky thing as when the car sat all those years untouched there were very few brake problems. The master cylinder was rebuilt again even though it appeared to be fine but we didn't want to take any chances. Also rebuilt the front wheel cylinders. But the silicon saved the brake system for sure. I don't know the shelf life of unopened containers of silicon. But when my friend David said we needed brake fluid we opted not to take a chance using the old bottles I had for ever and went out and bought some fresh stuff. JohnComment
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Re: 63 Master Cylinder
Hi John......what makes you think the DOT 5 might go bad. I got about 8 or 10 qts 16 or 18 yrs ago and am still using it with no ill affects.....Regards FrankComment
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Re: 63 Master Cylinder
Frank, When it came time to use the Dot 5 I told my restorer that I had a couple of new qts that I bought in the early 80's. He said why take a chance so he bought new. Glad to hear that it has a long shelf life. I can remember one time using it to shine up the blackwalls on my Model A pickup. Thanks for the imput, JohnComment
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Re: 63 Master Cylinder
Hello Rick; I have restored over 200 63 master cylinders and I have found that some of the rebuild kits have pistons in them that have an O ring as the main seal instead of a seal that has a sharp leading forward edge. When the piston with the O ring is used it will bind up as it tries to move back to the home position. Hope this helps? AndyComment
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