Brake Master Cylinder Questions

[twsutt]

Yesterday I changed my Brake Booster and 7/8" Master Cylinder (both rebuilt). I set the pushrod on the new Booster to the same length as the old Booster. The new MC isn't the same manufacturer as the old MC. One is Nabco the other is Tokico - I just don't remember which is which. The old MC had the bleeder screws on the fender side (left) while the new MC has the bleeder screws on the engine side (right).

Does anybody know if the pushrod distance should differ any for the different makers of Master Cylinders? And what is the flat-head screw on the side of the MC for/do?

Thank you,

Terry

[Nissanman]

The flat head screw is, I think, P/N 17 in the diagram.

NOT USER SERVICEABLE as they say:finger:

[Arne]

The basic pushrod setting should be the same for any master cylinder that is properly designed to fit your year Z, regardless of maker. That said, the reason that such things are adjustable is to make allowances for things like different manufacturers with slightly differing manufacturing tolerances. So a small adjustment might be needed.

[Rockr69]

the flathead screw is just what the exploded view ledgend says, Stop Bolt.

[twsutt]

Nissanman - thanks for the diagram. Okay, Stop Bolt, keeps the pistons from travelling too far.

Arne - thanks for the pushrod response. I matched the pushrod on the new booster to that of the old booster. Hopefully, this should work fine - if it needs adjustment I won't be too far off to begin with.

One other question: After bench bleeding, how does one remove the bleeder hoses from the bottom and attach the brake hoses without the brake fluid leaking out rendering the bench bleeding useless?

I haven't done this yet and don't know if I'm asking a stupid question or not. It just seems like gravity would make the brake fluid leak out or is it like holding one's thumb over one end of a drinking straw to keep liquid from draining out?

[Arne]

One other question: After bench bleeding, how does one remove the bleeder hoses from the bottom and attach the brake hoses without the brake fluid leaking out rendering the bench bleeding useless?

I haven't done this yet and don't know if I'm asking a stupid question or not. It just seems like gravity would make the brake fluid leak out or is it like holding one's thumb over one end of a drinking straw to keep liquid from draining out?

It will leak, but it won't completely un-do what you did on the bench. The purpose of bench bleeding is to get the air out of the master cylinder valving, not to be totally ready to go. You will still need to bleed the lines at the master cylinder after final installation.

To minimize the leakage, I normally bench bleed, then re-insert the shipping plugs while I move the cylinder from the bench and into the car.

[twsutt]

To minimize the leakage, I normally bench bleed, then re-insert the shipping plugs while I move the cylinder from the bench and into the car.

What shipping plugs? It didn't come with any shipping plugs.

It did come with a bench bleeding kit that consisted of two green plastic nipples and two pieces of clear tubing (about 4" long) that's too short to use for bleeding even without the plastic resevior cups attached - which have to be reused from the old master cylinder. *Things to remember if buying a rebuilt MC made by Cardone from Advance Auto Parts.*

[beandip]

I hope this info isn't too late. There is a thrust washer inside the booster that the push rod rides , the rod then goes into the back of the master. DO NOT pull the rod out of the booster. If you do the thrust washer will drop out to the side. When later you then press on the brake pedal it will go all the way to the floor.

[Weasel73240Z]

I'm trying to dis-assemble my master cylinder for a re-build. I've removed the primary pushrod, but I can't get the secondary pushrod to come out. Anybody know any tricks to get the secondary rod out? Thanks in advance for any help.

[Weasel73240Z]

Sorry to hijack the thread, this was supposed to be a new topic but I screwed up, my bad.

[Arne]

What shipping plugs? It didn't come with any shipping plugs.

It did come with a bench bleeding kit that consisted of two green plastic nipples and two pieces of clear tubing (about 4" long) that's too short to use for bleeding even without the plastic resevior cups attached - which have to be reused from the old master cylinder. *Things to remember if buying a rebuilt MC made by Cardone from Advance Auto Parts.*

I'm trying to dis-assemble my master cylinder for a re-build. I've removed the primary pushrod, but I can't get the secondary pushrod to come out. Anybody know any tricks to get the secondary rod out? Thanks in advance for any help.

I have years of experience in brakes, and I will NEVER use a rebuilt brake master cylinder, or rebuild one myself unless new ones are simply not available. When I did this stuff for a living, I never had a rebuilt master cylinder last even through a 90 day warranty. Never. Not once. Installing a rebuilt master cylinder back then (10-15 years ago) was a sure-fire guarantee that we would be doing the job again after a short time. For brakes, it's just simply not worth it IMO.

[Bruce Palmer]

.... rebuilt unit, I'd open it up and wash any machining grit and filings out before putting it into use. Have seen several that were just little "grinders" waiting to eat themselves alive.

Bruce Palmer

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