Brakes - Combination Valve

[Jason Spears]

I've just finished replacing my master cylinder for the second time in a week (I hate recon parts) and had a heck of a time bleeding the rear brakes.

Anyway- the button that is under the rubber cover on the combination valve. I've read in other posts that if this is pushed and held in it will allow brake fluid to flow freely through the valve. How hard should it be to push this in? I tried to push it in but couldn't. Is it time for a new valve?

Thanks for the help.

Jason

[swervin ervin]

You don't push it in, it's already in. All you want to do is remove the rubber cover and place a piece of tape over the pin to keep it in. It don't take much to hold it in as it's not under any pressure. I found doing this makes it a lot easier to bleed the rears.

[Jason Spears]

Well, I checked out my master cylinder when I got home from work today and it appears to be leaking again! It is leaking out the back. Like I said above this one was the second one in a week. I just have one question. Could the brake booster have filled with brake fluid and it is now just leaking out when I apply the brakes? If this is the case, should I replace the booster? The brakes feel great, 100 times better than before I replaced the original master cylinder. Any suggestions?

[swervin ervin]

No, I don't think the booster would fill with fluid. It may have gotten some right at the end and it may be leaking out what is left there. How bad is it leaking? If it's a Autozone special master and it proves to be bad again, take it back for a refund. Then buy a Bendix or similar. Them no name overseas units suck big time, as you already found out I think.

[Jason Spears]

It's leaking the same as the other two. The whole bottom half of the vacuum booster is wet. (I made sure to clean it off really well with brake cleaner to check for leaks when I finished the job.)

I called up my fiance's cousin who is a GM tech and got him to order me a new GM unit (he gets a really good deal!). After four or five trips to the parts store, four litres of brake fluid (I had a hell of a time bleeding the rear brakes), two evenings and getting rained on, I'm fed up. I'm never going to buy a reconditioned master cylinder again!

Thanks for the help Swervin!

[swervin ervin]

Good for you Jason.

The trouble with these junk parts is how they are rebuilt and who does the work, or lack there of. Most of the cores they get when you buy a rebuilt one are junk, or else they wouldn't be buying another one. They are pitted in the bore and if they don't leak soon, will before long, or either quit working altogether. I know some will say they bought one and have no problems. This is rare. They got lucky and got one that wasn't in bad shape before being rebuilt. Then they say, well, if it quits, they will give me another one. Fine. But who wants to be out in the middle of Bung F--k Eygpt when it quits?

I prefer to pay more for a product if I have a good feeling about what I'm buyiung. Not buy something worrying if it will work or last.

Maybe I have helped convince another person to spend wisely and buy good parts. I know how it is to not have much money and have to buy cheap stuff. But how cheap can it be if you have to keep changing the same part all the time. My time counts for something.

Good luck with it Jason.

[NeCrOmAnCeR]

Come on Swervin, I (we) have nothing better to do than spend six hours on a 30 minute job because we had to sort through the entire inventory of the local twilight zone for the one and only decent part. Nothing like replacing a part 6 times. But hey, it's a lifetime warrenty!!! the small print reads "may take your lifetime and that of your offspring to get a decent part..." The only rebuilt parts I use are those that I rebuild myself.