Thread: Replacing Master Cylinder..

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I have a 66 Chevy Impala, all drums. My master cylinder is leaking where the two bolts are on the booster.

I know the master cylinder is leaking but heres the problem:
What kind of master cylinder do I need to buy to replace it?!
also I DO have power brakes because I was lucky enough to find the original sales sheet.. sooo

There are kinds out there saying Manual brakes, Power brakes, some have this "With Metallic Lining" and some with "Without Metallic Lining"!

I'm thinking I need to get this one but i don't know anything about this.. I'm just going to do a stock replacement.. I don't want to buy a rebuild kit because I'll have to hone it out.

Is this a decent one? I don't have much cash on hand and I want it to stop leaking for safety's sake.
http://www.partsamerica.com/ProductD...pe=230&ptset=A

Also I'm a complete moron when it comes to suspension, could anyone clue me in as to what all this replacement will involve me doing? Bleeding the lines and just simply bolting on the new master cylinder orrrr is there something i'm completely missing!

heres the real problem, your master cylinder is leaking into the booster from the primary cup, so you will likely need a new booster. that single master cylinder don't look right for a '66, do u have a single master on your car? go to Napa, carquest or wherever tell them what you have with all details, and tell them u need a master cylinder for it, they can get what U need. the metallic and non metallic is probably the diffrent brake linings used.

No magic here. Just go to your local Autozone, Discount Auto, etc. tell them '66 Chevy, power brakes, whatever engine and trans it has, so they can plug it into their little computer, and they will pull the right M/C for you. You will probably get 3 or 4 choices as to warranty (lifetime, etc)

Replacement is a cinch. Put the new one in a vise with fluid in it, they give you a couple hoses to use as bleeders, follow the instructions, and keep pumping until all bubbles disappear, and you are ready to install.

Use correct sized line wrenches to remove the old lines, while the old M/C is bolted in place (if you have none, buy at least one properly sized line wrench so you don't bugger up the fittings........usually need two sizes) Once the lines are off, quickly unbolt those two bolts onto the booster, and slip the new one on and bolt it down. Then screw in the two lines into the correct holes, and tighten down snugly.

You have pre-bled the M/C in the vise, so most of the air should be out. Sometimes this will do it, sometimes you have to bleed it more at the wheel cylinders. You may luck out. On a one to five scale, five being the most difficult, this is a two.

If you don't feel comfortable doing it, don't. Brakes are nothing to mess with.

Also, the leaking fluid may have wiped out the booster, maybe not. Buy a quart of fluid, you will need it.

Good luck,


Don

well my car brakes just fine
it just leaks it and i have to fill up every so often.

also, yeah it does look like the one for mine, exactly like it.
I have a single bowl.

Well I asked my mechanic, that has faith in me (LOL), he thinks its just the master cylinder. I went and picked one up for 30$, core charge 15$. so i'll get that half back.. if anything after my tax return comes, we'll find out if its just a master cylinder going bad. And if my booster goes bad.. I'll just spring for the booster/Master Cylinder replacement and keep the master cylinder as a backup in my box of goodies.

I mean. It IS 40 years old..

Also if I do end up having to replace the booster.. will i have to buy a booster thats the same diameter as the original or could I get one for say.. a Nova or Corvette? Does it really matter? Because mine is just a single bowl master cylinder..

and.. whats ya'lls thoughts on the booster? still think its bad even though it works?

Boosters don't like brake fluid. Failure is guaranteed if any fluid got inside your booster . . . it's only a matter of time. I'd replace both the booster and the master at the same time. Use the same type as you take out of the car to minimize any surprises.

funny thing. i replaced the master cylinder to discover theres a dust cover that prevented any fluid from getting in the booster! lucky!