Ok i want to get a new MC and cannot decide which 1 to get. There are like 8 different ones. I work at napa went to look at our top of the line MC and its Cast Iroc WTH. Then i goto advance and all there high end ones are cast iron. Im really confused was the aluminum not holding up as well or something. Look here at the advance site i would appreciate the help i will buy one this week after i decide. http://www.partsamerica.com/SelectPa...aster+Cylinder

 

The factory ones were aluminum, and there were only 2 of them, I believe, at least for 1984 and later.

 

Yeh i know that but im wondering why the New ones from auto part stores are cast iron. Also does any one know how to check the booster im getting good vacume to it.

 

Do the auto parts stores even carry new master cylinders? I was under the impression most are rebuilds.

If they do carry new ones, then that may explain the cast iron. The company they buy from is probably making a knock-off version and the cast iron is cheaper.

You can get a band new genuine GM unit thru Dal at Vandevere Pontiac or GMPartsDirect.com, but be prepared to pay $200. That's the route I chose.

 

Take a look at the link i posted the most exspensive ones are cast iron where the aluminum ones are cheaper. They even said they could get a new aluminum one on the phone. I imma just gonna get the rebuilt aluminum bendix 1. Most likely

 

Ahh the link doesnt work like that u still have to look it up.

 

Ok heres is what is weird the new bendix is cast iron the reman bendix is aluminum. Are they all just to cheap tp make the aluminum new or does the cast iron hold up better.

 

nock on wood my alluminum one is 20 years old. i have replaced a few cast iron ones. i think the ci corrodes faster due to moisture in the brake fluid, also lighter.

 

Aluminum MASTER cylinders? I don't think I've ever seen one...the prop valves, yes but not the masters...we talking about the same things here?

Ed

 

Yes we are all the ones i ever seen on a third gen were aluminum.
This is the first time ive ever seen a cast iron one.

 

Left side is new bendix right is remaned bendix. I think there was like a 4lb difference.

 

What makes you think the one on the left isn't aluminum?

 

Because i seen it in person and it was alot heavier.Gee I know aluminum from cast iron.

 

It'cast iron, I installed one a few months ago on my car because I didn't want a rebuilt one. Bendix still sells them new for $$$

 

I just decided to buy the rebuilt one i dont see what the problem would be all the seals and such are new. I also wanted the light weight to keep the weight off the firewall.

 

I just got the $24 Cardone 102057. It is aluminum.

 

Yeh i was also kinda lookin at the cardone setup that came with the booster and all.

 

Is there a difference in the 89 RS master cylinder from the 91 z28 one?? I'm doing a swap and want to know if I should change the master cylinder along since I'm switching to the z28 4 whell disc.

 

No difference

 

Hey guys, cast iron was the early 3rd gens, at least 82-84. Aluminum came later. The cast iron ones can rust out inside the main bore, and that can both cause leaks and tear the primary piston's seal.

With a rebuilt unit, it will be a toss-up as to whether you get cast iron or aluminum.

And yeah, a new m/c will be $200 and up from GM.

[edit: added below section]

Oh as for all the confusion with the # of m/c's... 82-88 used a 1 inch (25.4mm bore) master cylinder for "J65", the 4-wheel-disc option.

82-88 "J50" (disk/drum) and 89-92 "ALL brake combinations" used the 24mm bore master cylinder.

Apeiron (on these forums) found an old GM service note to technicians, if someone bought a 4-wheel-disk car and complained that the brake pedal was too hard to push, GM said that the 24mm (J50) m/c could be put on the car. GM used the 25.4mm (1 inch) m/c for J65 cars to give drivers an "increased pedal feel". My guess is that a ton of weak-footed fast-car driving people complained, and GM just got fed up, and used the 24mm J50 m/c from 89-92 just to stop people from whining.

SO... I'd imagine you could put a J65 m/c on an 89-92 car if you wanted increased pedal feel- but don't quote me on that!! I don't know if there will be any issues with the fancier rear calipers that the 89-92 cars got.

 

These were all for a 90 camaro tho i was lookin at and i know 88 and earlier disc had different MC that were alminum also. IS what you are say is that all the drum cars and 89-92 disc cars had the same MC. So then the older drum cars were cast iron. All i know is mine better be aluminum when it comes in cause they says whats in the picture is what you should get.

 

Spd, check out the whole paragraph I just added at my last post, you might've missed it. I should've just added a new message; my mistake! But that should explain why there were so many m/c's listed.

 

Yep, I'm an idiot...mine's aluminum too.



Ed

 

Yup thats what i was thinking so when they make the new ones they just do the cast iron design. Anyway i better get a aluminum one or they will be returning it. It suppose to come in tomorrow.
TomP figured it out your the man!

 

Ok im gettin pissed on this MC ****. First 1 i got the resivoir was as dirty as mine. Second one i got the body itself was all nicked the hell up. I think im just gonna buy a rebuild kit then Auto Zone sells the new resivior looks just like stock. Ed have you rebuilt a MC how hard is it. How do they come apart any way.

 

Sorry, I've never rebuilt one, nor did I buy a rebuilt one. The one on my RS is the stock one and the one on my Iroc is a used one, but it doesn't look too hard to do.


Ed

 

I bet its not

 

Hey TomP what about rebuilding my MC i cant find any good remaned units. They all look like crap and mine looks in good shape from the outside all except the resivior. I just dont want to mess anything up and waste time and money. I tried to PM you but your box is full. I thought i seen a thread about you rebuilding a MC.

 

OK so some1 help me out. I just ordered a new one in here at napa looks real nice but... is cast iron. Should i just buy it since i can get it for 67 dollars or what. I could just use my aluminum 1 but its over 10 yrs old ide like to have a new one. Would it hurt anything other then just adding weight. This suxxxxxxx!

 

What's wrong with yours now?

 

I just figured its old and would be a good idea to replace it. Since im doin everything else. Gm Parts direct supposely has it but who knows if it is aluminum either. 127 also

 

If there's nothing wrong with it I'd just leave it.

 

Yep, I rebuilt mine. Rebuild kit was $25, by Bendix... don't have the part # handy, though.

Here's my story... bought the disc axle and the m/c and prop valve. The m/c was rusted to hell, so I traded it in as my core for a rebuilt A1-Cardone unit. I bled the system for a week straight before deciding it was a bad m/c. So, I took the m/c back and got another A1-Cardone piece. Worked for a while- and then the rear seal tore. Brake fluid was leaking down my brake booster.

So I rebuilt it myself. I have a theory... I think that they rebuild these master cylinders, and then they sit in a hot warehouse for a long time before someone needs one. By then, the seals probably dry up, so when you first install it, you probably tear the seal a bit b/c it gets stuck to the bore. So I think by rebuilding it myself, I was able to put fresh seals in, without them ever drying up.

Found the part #!! I posted it on thirdgen.org a while ago. For the J65 (4 wheel disk) master cylinder, it's Bendix part # 22232, and it cost me $30- slightly more than an already-rebuilt master cylinder, but I think it was worth it.

The rebuild was easy, once the old snap ring was out, everything else just popped out. I assembled the new primary piston and seals into the m/c as my GM service manual told me, bled it with my V12 Phoenix Injector (see http://www.brakebleeder.com ), and was good to go. See https://www.thirdgen.org/techbb2/sho...threadid=58931 for more info.

Oh and that "bleed-while-rebuilding" idea of mine was worthless. When you push a piston into the m/c body, any fluid in the bore shoots out, and you still wind up with air. I guess I would've had fill my bathtub up with brake fluid, and rebuilt the whole m/c while submerging everythign in the bathtub.

Oh and remember- if you get a cast iron one, eventually, that cast iron will start to rust inside!! (Brake fluid absorbs water.)

 

So you think it would be ok if i rebuilt my stock aluminum one. I heard somethin about having to hone it or some crazy stuff?
Also i am goint to buy a v12 what about from here Tool Paradise
Was it the smart pak and case that you got.
Also i will be using silicone fluid.

 

Also Tom i just read my service manual doesnt look to hard at all. Correct me if im wrong but i read replace if it is corroded other wise your ok.

 

Yep, that's the same V12 I bought (w/smart pak and red case), but I paid much more. Oh well. It was worth it at the time! I was so sick of bleeding the brakes over and over and over and ... The smart pak is basically all fittings and tubes to fit most systems, and the red case just looks damn cool. Hey when you try it out, let us know what you think of it! Everyone I've talked to says that they love it- even my mechanic has one. (He also told me that I paid too much!) Although, mine came with a video on brake bleeding; that parts description didn't mention a video. But, the manual is amazing on it's own!

Yeah, you got it; usually you replace/rebuild only if the m/c is corroded up, or a seal is torn. Otherwise, it's up to you if you want to rebuild it or not. Like you said, it's not hard at all, as long as you get the new seals aimed in the correct directions, there's nothing to worry about. I even worried a bit about pushing the primary piston into the bore, since the new piston seal would rub against the snap ring groove for the final 1/2 inch of "insertion"- but I just slathered everything up "overkill" with brake fluid, and everything's been okay with the rebuild. It's been, oh, what, like 3 years so far, and nothing's leaking.

As far as honing, I read somewhere that you're not supposed to hone an aluminum-bodied master cylinder; something about a coating on the inside? And usually you'd just hone a m/c if the bore was rusted, which won't happen with an aluminum m/c. The honing confuses me anyway; say the m/c was iron, and I went to hone it- how the Heck would I get all the metal filings out?? It doesn't make sense; I think that filings would be floating around and possibly getting into the seals and ruining them. Does anyone know?

 

So what manual did you use i only have the Haynes seemed pretty good tho. Ide like to get the chilton they look like they might be better. Yeh my MC doesnt leak now but with the old seals who knows how long ide feel better rebuilding it. I could also try to polish it up with it all apart. Ide just be afraid of debris getting inside. You could always wash it out tho i guess .

 

Actually i have the GM service manual (from http://www.helminc.com ) but the procedure in the Haynes is an almost-exact photocopy of what's in the GM book! Same thing with the caliper rebuild pictures. I cut open an empty oil bottle "sideways", left the cap on, wiped it out with paper towels, and poured brake fluid in it. Then I dropped the new seals into the cut-open-oil-bottle "pan", so as I rebuilt the m/c, the seals were wet with fluid.

Oh if you work with enough brake fluid, it actually seeps into your hands (since brake fluid absorbs water). By the time I was done with all that constant brake bleeding, my hands looked like a 90 year old man's hands- all wrinkled up, and I couldn't feel my skin!! After a few days they went back to normal, now I always wear rubber gloves when I go near brake fluid- that was scary.

 

Yeh i was looking at all the bleeding procedures on the pheonix site last night. Was getting me excited about getting it which 1 did you use. I might pressure first to get all the old fluid out then i might do a RFI. Did you jack up the back of the car higher to level the MC.

 

Have a 1990 with disc/disc. Upgrading to LS1 front's and am suspicious the quick take up valve isn't functioning as I have a lot of pedal travel, and get the geyser described with a bad valve. However, I too have been unable to find an aluminum M/C.

The one from GM parts direct is aluminum but was beat to hell and then they told me it was a remanufactured part! I told them forget it.

My question is do the M/C rebuild kits come with the quick take up valve as it is described as "non-servicable" in the manual. If not where can I get the valve. I assume the reman M/C's have a new one.

Also contemplating the true J65 25.4mm bore M/C for a bit firmer pedal. Anyone have a P/N for that?

Thanks

 

Shoot, it's been a while, but I believe that first I bench-bled the m/c, then installed it. (I had tried raising up the back of the car before I had the PI, and it didn't work.) After I bench-bled the m/c, then I connected it, bolted it to the car, and used the UPA (universal port adapter) to pressure bleed the system from the m/c out to each bleeder valve.

Keep in mind too that I had bled the system so damn much that I already had fresh fluid throughout everything, so I didn't need to do a flush. I should do one this summer, though.

Feldme, a remanufactured J65, by A-1 Cardone, is number 10-1997. You could do a search on carparts.com or expressautoparts.com or partsamerica.com to find out other manufacturer's part numbers, be sure to put in an 84-88 f-body with rear disks. (82-83 will be SAE threads, not metric, and it won't fit your car.)

The kits don't come with a quick take-up valve. It's actually sealed up inside the master cylinder housing. The QTV is a pain in the butt to bench bleed without any special tools (like the PI); you'll need to short-stroke the m/c piston with a screwdriver, and you also need to wait 20 seconds between strokes for the QTV to fill up with fluid.

 

i don't really understand why there sems to be so much trouble with bleeding the brakes on third gens!! You can get a bench bleeding kit for a few bucks or make one your self. you just need 2 stubs of brake line with fittings that you bend around to dump into the resovoir. Mount the MC in the car, fill it with fluid, then with the bleed lines install slowely stroke the pedal. Go all the way down and wait about 10 seconds then do it again until clear fluid with no bubbles is returning to the MC. After that remove the bleed lines one at a time and reconnect the brake lines. pump the brakes slowely but firmly 3 times then hold the pedal down, have someone crack the lines. Do not let the pedal return until the line is closed!! do the same at all 4 wheels and again at the MC. your done.

I have used pressure bleeders in the past because they are convenient and a one man operation but i never found them neccessary.

 

Why if there is a way that is 1000x's easier i dont understand why we have cars either if i can ride my bike to work. Better also!