Wrong master cylinder - should I worry?

[RaeRae1]

Thanks again Bob, I just might PM you but I have a copy of the complete factory manual, it is just a little confusing how they say to measure the depth. I'll see if I can get it, if not I may be sending you a scan of the page to see if you or someone else can help!

Here is a quick update.

Got the new adjustable proportioning valve, got the adapters to make it all work and put it in this weekend. Have bled the system with the “open, press pedal, close, release pedal” to the tune of three small bottles at all four bleeders. Still no change in pedal feel. Haven’t actually put it down and taken it for a drive, but I’m almost certain it will do no good. I know how the pedal should feel and this one is definitely soft for the first half and solid for the last.

Sooooo… - since the brake lights are now off after rebuilding the proportioning valve/distribution block, and there are no visible leaks, this leads me to believe the problem is between pedal and master cylinder. I am going to be removing the master again, re-bleeding it, and double checking the push rod length just to be sure. Then, if I get it back together and it still doesn’t work?

I think I have a noose somewhere…. And a chair…

Kidding…….Just kidding!!!!!!


Dumb question though, just to reiterate my knowledge – the brake booster. If I am not mistaken, this only creates strong power to the pedal (pushing strength so to speak using vacuum) and does not really affect the braking. Is this a correct assessment or should I look into this being an issue as well? The brakes are soft with the car off. However with the car on and the booster in operation, it is hard to judge pedal pressure and when I drive it there is no question the booster is operating at max.

[RaeRae1]

Double post *durrr*

I hate the lag on this board sometimes

[bobss396]

Since the pedal is soft, I would think about moving the rod out somewhat. Go like 1/8" at a time until you start getting some reaction. Try applying the brake now and see if someone can turn a front or rear wheel against the action.

You should still get a good firm pedal without the power assist. I think that you can factor the booster out as a problem.

The only thing I can think of right now that you have a missed leak somewhere, so check all the lines and hoses. Rinse off any residual brake fluid with a hose first and let it dry. Aside from that, go with the rod adjustment and monitor the progress, if any. If you still are getting nowhere, you might have a bad master cylinder that is bypassing internally.

Bob

[RaeRae1]

Originally Posted by bobss396

Since the pedal is soft, I would think about moving the rod out somewhat. Go like 1/8" at a time until you start getting some reaction. Try applying the brake now and see if someone can turn a front or rear wheel against the action.

You should still get a good firm pedal without the power assist. I think that you can factor the booster out as a problem.

The only thing I can think of right now that you have a missed leak somewhere, so check all the lines and hoses. Rinse off any residual brake fluid with a hose first and let it dry. Aside from that, go with the rod adjustment and monitor the progress, if any. If you still are getting nowhere, you might have a bad master cylinder that is bypassing internally.

Bob

I think I may have found a leak.

Is it possible to have a bad flare on the tube? The fitting going to the proportioning valve seems to be leaking. It seems as though the flare is not seating correctly on the inverted flare of the prop valve. I took off the line, inspected it, looked for any cracks - it looked just fine so I put it back on, tightened it down very snug and... still leaks rather bad when I step on the brake.

I am thinking perhaps I need a whole new line? It is a rather short one. I was told that I can just get a kit that has the flare tool etc. and make my own line. Good idea or no?

Thanks

[bobss396]

I knew it! A confounding problem has been found!

I have such crappy luck flaring brake lines that I buy pre-made sections and just bolt them on. Brake lines are a double flare and hard to do, at least for me. You could pay someone to make you up one, shouldn't cost that much considering all you've been through.

How long is the line? Most better parts stores have an assortment of brake lines ready to install. They come in 10" increments, have the fittings on already. I'm not sure what they start at in lengths either.

Bob

[MagicRat]

Originally Posted by bobss396

I knew it! A confounding problem has been found!

I have such crappy luck flaring brake lines that I buy pre-made sections and just bolt them on. Brake lines are a double flare and hard to do, at least for me. You could pay someone to make you up one, shouldn't cost that much considering all you've been through.

How long is the line? Most better parts stores have an assortment of brake lines ready to install. They come in 10" increments, have the fittings on already. I'm not sure what they start at in lengths either.

Bob

Great advice! I used to buy pre-made brake lines in various lengths. I found the lengths used on older cars by the factory often are identical to the lengths available at an auto parts store.

BTW the 'secret' to flaring your own brake lines is to use a plumber's pipe cutter (the wheel type) to cut the line........ and then file off the last 1/16 of an inch off the end you have just cut.
The cutter wheel will 'work-harden' the metal of the brake line at the end, making it nearly impossible to flare without cracking. This hardened metal can only be removed by hand- filing it off. Anything else results in too-rough a cut.

[RaeRae1]

Originally Posted by bobss396

I knew it! A confounding problem has been found!

I have such crappy luck flaring brake lines that I buy pre-made sections and just bolt them on. Brake lines are a double flare and hard to do, at least for me. You could pay someone to make you up one, shouldn't cost that much considering all you've been through.

How long is the line? Most better parts stores have an assortment of brake lines ready to install. They come in 10" increments, have the fittings on already. I'm not sure what they start at in lengths either.

Bob

Ok. I'll check around and see. The length is probably only about 12" when it is straight. It is the line that goes from the distribution block to the proportioning valve - just a shortie. The flare sure looks ok but regardless it is leaking. What kills me is all this time we have been going to NAPA and or a place called Page brake and no one has mentioned a new line - they just keep trying different adaptor fittings. I have a local muscle car forum here and someone on there has offered to come take a peek. He has a flare tool of his own so perhaps together we can get it done.

I'll keep ya updated.

Thanks again Bob

[RaeRae1]

Originally Posted by MagicRat

Great advice! I used to buy pre-made brake lines in various lengths. I found the lengths used on older cars by the factory often are identical to the lengths available at an auto parts store.

BTW the 'secret' to flaring your own brake lines is to use a plumber's pipe cutter (the wheel type) to cut the line........ and then file off the last 1/16 of an inch off the end you have just cut.
The cutter wheel will 'work-harden' the metal of the brake line at the end, making it nearly impossible to flare without cracking. This hardened metal can only be removed by hand- filing it off. Anything else results in too-rough a cut.

I'll give NAPA a call here and ask.

I am certainly not going to try to flare my own without watching someone who has done it before. I'm bound to mess it up, especially if it has anything to do with the cougar!

Thanks MagicRat.

BTW - forecast is for snow this weekend. I didn't make it

[MagicRat]

Where is your sense of adventure???
Of course you can make your own flares. Here is a video that shows you how.:

http://www.expertvillage.com/video/9...kes-custom.htm
BTW my sound card is down, so I could not actually hear the video. But the guy seems to be waving brake lines around in a convincing manner.

Also look at these, for more info.
http://www.carcraft.com/howto/116_07.../photo_05.html
http://www.ehow.com/how_2320217_make...rake-line.html
http://www.stu-offroad.com/suspensio...etool/ft-1.htm

[RaeRae1]

Originally Posted by MagicRat

Where is your sense of adventure???
Of course you can make your own flares. Here is a video that shows you how.:

http://www.expertvillage.com/video/9...kes-custom.htm
BTW my sound card is down, so I could not actually hear the video. But the guy seems to be waving brake lines around in a convincing manner.

Also look at these, for more info.
http://www.carcraft.com/howto/116_07.../photo_05.html
http://www.ehow.com/how_2320217_make...rake-line.html
http://www.stu-offroad.com/suspensio...etool/ft-1.htm

Sense of adventure??? perhaps I should really try out my sense of adventure and just drive the thing with the brakes the way they are...

Thanks for the video - I'll have to actually LISTEN to it and see if it actually is someone talking about brakes or just using brake lines for a new art project.


Seriously, thanks of the links. I should be doing some of that myself but I am swamped lately and have limited internet time. The time I do have my hands are too greasy to use the computer!

(yeah, I like smileys, can ya tell?)

[RaeRae1]

Originally Posted by MagicRat

Where is your sense of adventure???
Of course you can make your own flares. Here is a video that shows you how.:

http://www.expertvillage.com/video/9...kes-custom.htm
BTW my sound card is down, so I could not actually hear the video. But the guy seems to be waving brake lines around in a convincing manner.

Also look at these, for more info.
http://www.carcraft.com/howto/116_07.../photo_05.html
http://www.ehow.com/how_2320217_make...rake-line.html
http://www.stu-offroad.com/suspensio...etool/ft-1.htm

By the way, the stu-offroad link was not only greatly informative, but also pretty funny!

[RaeRae1]

After 5 different stops I was finally able to get a brake line the right size. First stop was our local Page brake... the didn't have a brake line. So, off to Napa - they had a brake line but not the right fittings on it to fit.. so, off to another parts store - they had two different brake lines, one too large, and one the right diameter but not the right lenght. So, we sent back to Napa and picked up the right length and diameter line, then went back to Page brake and picked up a fitting that would piggy-back the original fitting to get them to work. So, got it all together and it appears as though.....


drum roll please....


NO LEAK!!

So, we rebled the system....AGAIN. I'm still a little worried however, because the pedal still doesn't feel like I think it should. We have the car of the stands and on her wheels but havent been able to drive it yet because of a dead battery. I'll let you know in the next few days what happens. I have my fingers, toes, and eyes crossed! hahaha

[bobss396]

No leaks, you guys know how to party! I prefer to buy pre-made brake lines rather than make them. But you have to hit a place that has what you need.

If the pedal is still not that high, look to do an adjustment on the rear brake shoes. This is what gives you a higher pedal, which should get better once the shoes break in.

You can do it with the wheels on the car if you want to, but jack it up first. Just a couple of clicks at a time until you feel a slight drag. Make sure the drag is slight, as the drums are much more easily turned with the wheels on and the tendency is to over adjust them.

Bob

[RaeRae1]

Allllright guys and gals, I'm back with bad news. Yeah, it is still not working.

Here is the progress. After fixing the leak at the prop valve, the road test turned out bad. Still about the same issues. So, from there we went and got brass plugs to plug off the MC to give us some diagnostic as to if it might just be a bad MC. Well, the pedal was very stiff with the mc blocked off but there was a lot of top pedal play first. Soooooo

From there I bit the bullet and took the booster and MC back out and looked carefully at the push rod adjustment. It was a little short so we adjusted the push rod out. Put it all back together and the pedal definitely feels better but there is still something wrong.

We completely turned off the back brakes with the new adjustable prop valve and went strictly with the fronts. They aren't giving adequate stop. The can stop the car, barely, so that indicates they are getting some movement, but obviously are not getting grab or enough force.

Any ideas from here? It is both front brakes - which I find rather odd. I inspected the line from the MC to the distribution block for leaks and there doesn't appaer to be any.

I didn't know satan was in the brake business...

[bobss396]

I would (cringing..) take the master & power booster apart again (you are a pro at it by now) and adjust the rod out another 1/8" and see what happens.

You made good progress with the last adjustment, so I thing all you need is a little more to get full travel within the master. Make the adjustments gradually until it stops well enough to make you happy. 1/8" increments are safe and sane.

If you go too far, the brakes won't release once it is fully warmed up. But that will be a matter of backing off the rod a little.

Bob