Replacing Master Cylinder

[Powerzen2002]

Hey, I noticed my break pedal was low ... when replacing
brake fluid, i noticed a leak coming from the master cylinder...

(on the 90 240sx its the black round thing holding up the
brake fluid resevior ???? ... )

Well, I was wondering how hard the process is?
How long it would take a newbie to do.
And is it worth it to do myself!
Like how much :(

Please, all help would be appreciated!

Thank You!

[gschroeder78]

I'm not a newbie as far as that kind of stuff goes but I did just do this a month ago. It's easy and a good 1st timer type repair.

A couple things you'll need are a flare nut wrench (10mm) this is important because the brake line nuts are way too soft and will strip with a normal open end wrench.

Removal:
-Basically just unbolt it from the booster. (2 nuts)
-Remove the brake lines (3 lines)
-You'll have to save the resivoir, just carefully pry it off.

Installation:
-Put the resivoir on the new Master Cylinder.
-You should bench bleed it (mine came with a little kit for this)
-Basically you push the hose attachments into the openings for the lines.
-Push a screwdriver or dowel into the end part to pump the air out of the cylinder. Just like bleeding brakes.(Kinda simplified but you can ask for clirification)
-Now just reverse the removal and it's in.
-You'll want to bleed the brakes afterwards.
JUST BE CAREFUL not to strip the brake line nuts.

It's pretty easy and should only take an hour, not couting time to bleed the brakes. Hope I helped.

Garrett

[Powerzen2002]

Thank you for the installation and all. How much does the
M. cylinder cost on one of these things? Hopefully not alot,
like the rest of the parts on this freakin car!

I definately do need to bleed the break lines dont I ....
I dont have a good jack, ill be there all day if I have to
remove each tire and bleed them ...

To bleed them, the nut is right there behind the wheel right?


EHhhhh ... thanks!

Jay :)

[Joe_M]

It cost me 55 dollars for the master cylinder from Advanced Auto Parts. It was a rebuilt OEM Nissan part with a 1 yr warranty. The MC from Nissan was almost 400 dollars! :eek:

The whole installation took about 15 mintues. My fluid had all leaked out of the master cylinder, so I didn't have to drain the resevoir. If you still have fluid in it, just use a turkey baster and suck out all the remaining fluid.

The only thing that was a little bit of a pain, was prying off the old resevoir.... those things are on there good! But my rebuilt MC came with new o-rings too, so I didn't have to reuse the old ones.

It's a pretty easy process to change out the MC. Just a few pointers to remember.....

Get a 10mm flare nut wrench. If you round off a flare nut, you're basically screwed.

Brake fluid EATS paint on contact. Be careful and use lots of rags.

Check the brake booster (black thing the MC attaches to) for corrosion and clean up as neccessary.

Don't move the push rod inside the brake booster.

Bleed the system afterwards. Use the search to find the correct method for either ABS or NonABS. I didn't feel like messing with it so I took it to Nissan and had them bleed it for 50 bucks.

Easy as that!


Joe

[gschroeder78]

I don't know if you can bleed them very easily without taking the wheel off. I've got a 2-ton jack so I just lift up the whole front and the whole back. But your right, without good tools it's a PITA.
Other than that, Joe-M said it.
Garrett

[kandyflip445]

If you don't have the tools to do it and you wanna keep servicing your car yourself you need to start building up your collection:D sometime. And yes you will have to take the wheel off. Unless you for some reason have a car lift...:p When you bleed a brake system you start from the highest thing and work your way down...Like, MC, combination valve, then the wheels in the pattern perscribed my the manufacturer. When you bench bleed the MC and put it back in it is a good idea to bleed it on the car again. Do this by taking the same procedures to bleed the MC but use the connections of the lines to the MC. Tap them LIGHTLY with a wrench to help air move up.