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  • March 28, 2024, 11:49:32 AM

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Author Topic: mysterious brake issue  (Read 14884 times)

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Offline packotobacco

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mysterious brake issue
« on: May 14, 2016, 12:27:42 PM »
Hi there fellow eagle fans. I must apologize if I'm posting in the wrong place however this was the only place i could find the option to post a question. In any case i have had an ongoing issue with the brake system on my 87 eagle lmt. It all started when i decided to replace/repair all of the hardware for both my front and rear brakes. I ordered new hardware kits for the drums and had my drums and rotors remachined. Afterwards i installed my new and next to new components an did a few runs back and forth to set the tensioner in the rear hardware by braking sharply in reverse. Once the brake seemed to be working properly i took her for a spin around the block. For about three days of short test drives my brakes worked better than ever, and my engine even seemed to perform better. But on one fateful press of the pedal i suddenly lost all hydraulic pressure and had to struggle to stop with mechanical pressure only. At first i suspected that i had messed up with the hardware but everything still seems AOK in that department. After that i pressed the brakes many many times with the engine running to make any potential leaks visible. However after a year, yes a whole year, of troubleshooting i can't find any sign of leakage in the lines or pressure vessels in front or rear. At this point i had to replace my calipers due to stuck bleed screws. Of course the rebuilt calipers leak around the cups, really wish they would check that before selling them but they probably don't care. I also replaced my master cylinder and brake booster just to be sure. So to sum up everything in my brake sytem is new except the rear pistons and they are in great shape for their age, the new pistons leak a bit but i think i ought to get some pressure after a fresh bleed and i still get mechanical pressure only. I will continue swapping calipers until i get a pair that doesn't leak and will update as soon as i can but i need to know if I'm over reacting or if i have bigger problems than slightly leaky calipers. Any suggestions might help, and feel free to ask about what I've tried already.

Sincerely
Packotobacco

Offline mudkicker715

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Re: mysterious brake issue
« Reply #1 on: May 14, 2016, 05:08:54 PM »
Have you checked to see that vacuum is actually getting to the booster.



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Offline johnbendik

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Re: mysterious brake issue
« Reply #2 on: May 14, 2016, 08:42:34 PM »
packotobacco,

In case it wasn't clear from mudkicker's reply, there is no distinction between hydraulic and 'mechanical' pressure; they are one and the same, in that the only way you can apply 'mechanical' pressure is through the hydraulic system.  If your brakes suddenly lost hydraulic pressure, the symptom would be a very mushy pedal, maybe even going all the way to the floorboard.

On the other hand, if your symptom is that your brakes suddenly lost effectiveness, forcing you to have to press extra hard on the pedal to stop, then you have a booster problem, not a hydraulic problem.  And the 'brake booster' on an Eagle is powered by engine vacuum.  The brake booster is the big black cylindrical thing between the brake master cylinder and the firewall, and if it's not hooked up to engine vacuum, you won't have any boost and the brake pedal will be very 'hard'.

Good luck with it,
JB
« Last Edit: May 15, 2016, 10:12:50 AM by johnbendik »
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Online amcfool1

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Re: mysterious brake issue
« Reply #3 on: May 15, 2016, 09:46:26 AM »
hi, the pp is right, sounds like a booster problem. if you replaced the master cylinder and the booster individually, they may not be adjusted to work properly together. The last time I did this, over ten years ago, I purchased a booster/master cylinder assembly together, from Autozone, to avoid any adjustment problems. good luck, gz

Offline AMC1

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Re: mysterious brake issue
« Reply #4 on: June 16, 2016, 09:59:31 AM »
just a couple of thoughts that may seem even silly to you, seeing as how it went for a year with no problem. I initially thought you may have reversed the rear linings. I had a hard time solving a similar problem until I found a weak spring which wouldn't let the automatic adjuster work. But you did say you used all new hardware. With the engine running you can pull off the vacuum line at the booster & put your finger over it. You'll know immediately if the line is working.
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Offline packotobacco

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Re: mysterious brake issue
« Reply #5 on: September 02, 2016, 09:28:52 PM »
Hello again first of all thank you all for your help and sorry for the length of time between posts. I did misspeak  when i said no hydraulic pressure. I have measured the vacuum at the booster but not recently. I got 17 psi ,or negative psi as it were. I know thats lower than the prescribed range but just barely, unless I'm mistaken. I've replaced many vacuum lines since then and figured this slight lack of vacuum could not cause my problem. Since my last post i have repaired the leaking calipers and still find no other issues with the lines. My master cylinder on the other hand seems to have bad seals as i can hear a swishing sound as the pedal is depressed. And it started leaking from the rear about two months after installation. Fortunately a company has started building new mc's from scratch so i don't have to trust a rebuilt one. I've been through three rebuilt units with no luck. Just to be clear i don't know for sure if the original  failure was vacuum or hydraulic. With my vacuum at 17 to booster i thought mc or booster b
f membrane. After replacing both components my symptoms remain unchanged,  but mc is bad for sure. Can the mc fail instantly and completely without leaking? Could i be bench bleeding incorrectly. And any info on the adjustments mentioned by amcfool 1 would be greatly appreciated.

Offline packotobacco

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Re: mysterious brake issue
« Reply #6 on: September 03, 2016, 09:26:18 PM »
after looking into the pushrod adjustment i realized that when i set it in the first place all i did was ensure that it protruded from the booster by the same amount as the old unit. I then realized that since the booster is new and slightly different shape there is no guarantee that the overall lenth of the assembly was correct. just purchased a truly new master cylinder and set my pushrod to be .020 thousanths short of contact as recomended by info i found online. I owe a big thank you to amcfool1 as the difference was nearly a full inch, and I would never have thought of that on my own. I will install as soon as my helper has time to assist in the bleeding process and post the results asap.

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Re: mysterious brake issue
« Reply #7 on: September 04, 2016, 12:04:35 PM »
hey, good deal! glad you got it sorted out.good luck, gz

Offline packotobacco

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Re: mysterious brake issue
« Reply #8 on: December 09, 2016, 09:16:33 PM »
Hey everyone ,back again with updates and, of course, more questions. Been two months since we bled the system but i couldn't post since my laptop got fried in a power outage. After setting the pushrod we bled the lines and i got full motion in the calipers and pistons and was ecstatic. Put the wheels on and test drove and felt great when the car stopped easily just as it should kept testing for a few blocks and had no issues. Had to park it again to tap two tranny pan bolt holes and refill .afterwards i tested the brakes again and all still seemed well. I parked it again to straiten out some vacuum lines and wait for my tabs to be worth buying as they would have expired after a single month. just renewed and took it for a spin and in perfect line with the luck I've had with this car, my easy powerful stopping ability slowly diminished and disappeared as i limped home with red face and white knuckles. I suspect the rear pistons have finally failed after receiving full pressure for the first time in years. I also need to adjust my idle settings since it wants to go even with out touching the pedal. Looking for new pistons now and after the caliper fiasco i want the first set i buy to actually work so any advice there would be awesome. Also i saw a post about the drum adjustment where someone stated that there could be a clog in a rubber hose before the drum. Been awhile since i checked but i thought the rear lines were all metal. Is there a hose hiding somewhere or was he thinking of the front hoses?

Online amcfool1

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Re: mysterious brake issue
« Reply #9 on: December 10, 2016, 12:40:27 AM »
hi, the rear brake lines are steel as they run along the axle, but, in the middle, towards pass side, is a flexible rubber line that connects to the steel line going to the front of the car. It is ALWAYS a good idea to replace the soft lines, both fronts and the one rear, if they are over 30 years old. They can deteriorate from the inside, and let little chunks of rubber clog your calipers/pistons, causing your brakes to lock up. This happened to me once , years ago, though not on an AMC.  As for rear pistons, get a name brand, don't go cheap. Personally, I like NAPA parts, but others are ok as well.
As for the MC failing altogether, yes it can, though it's designed not to. Years ago, I had a MC fail  COMPLETELY in an 82 Concord. Just by pure luck, the car was parked at the time in a Home Depot parking lot. Drove there fine, got back in, started out, and NO BRAKES whatsoever, had to walk home and get a tow. Could have been a lot worse, 5 minutes later I would have been on the interstate.
As for your high idle, your choke is sticking, before you adjust idle screws, make sure choke pull off is good.
good luck, gz

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Re: mysterious brake issue
« Reply #10 on: December 10, 2016, 01:10:58 AM »
hi again, just as an fyi, it's a good idea to have your brake fluid replaced every 3 years or so, even on new cars. This is a PITA to do by yourself, but most small good shops can do this for small $$. Whenever I buy an old car, AMC, or even a late model used car for my wife, the FIRST thing I do, before I let her drive it, is have the brake system completely gone through by a professional, and the fluid changed. Good brakes are your LIFE!
Along the same lines, it's also a good idea to change your Power Steering fluid. This is neglected by most people, Just top it up, and all good, right? Not really. The AMC, (Saginaw) PS system is excellent, and can live for decades, but contaminants still get in, and cause wear, and eventual steering box/pump failure. Changing your PS fluid is easy, if a little messy, and you WILL need a helper.
Disconnect the low pressure line at the steering gear. This is the crimped line, NOT the screw in one. Point it at a bucket. Run car. Have helper keep pouring in fresh fluid as it drains, when it comes out looking new, you are done, good for another 5-7 years! You will be surprised how ugly that old fluid is. And, while there, change the lines. Aren't Eagles fun?!
good luck, gz

Offline packotobacco

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Re: mysterious brake issue
« Reply #11 on: December 17, 2016, 04:41:49 PM »
Thanks for the info i'm still looking for leaks because i have just replaced both wheel cylinders and after a fresh bleed i thought i was good because all the brake slave pistons moved with the pedal and the pedal was high and firm. But as soon as i started it the pedal sank and even after adjusting the drums i'm getting no pedal. i keep bleeding this thing all the time so i can't imagine the fluid is old.  The front flex lines were the first thing i tried but when i changed the cylinders i still couldn't find a rubber section in the rear just that corrugated plastic covering. And just so no one worries i am not road driving until the brakes test good beyond doubt. I'm fortunate enough to have a virtually abandoned parking lot at the end of my driveway for testing. Anyway i had really hoped to sort this out myself ,at this point I've put so much into into it I'm on a mission.

Online vangremlin

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Re: mysterious brake issue
« Reply #12 on: December 17, 2016, 05:26:36 PM »
Man, this has got to be driving you nuts!  I can't offer any other suggestions, but I can point out that the rear brake rubber hose will connect to the rear steel brake lines on top of the rear axle on the passenger side.  Follow the steel line that leaves the passenger brake cylinder and you should find it with no problems. There is a block T-fitting on the end of the hose that sits on the axle, and the 2 steel lines screw into it.  I looked but there isn't a real good diagram in the service manual.  Good luck!
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Offline mudkicker715

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Re: mysterious brake issue
« Reply #13 on: December 17, 2016, 10:01:57 PM »
That is sounding alot like you are leaking from the master into the booster. I mean that really really sounds that way. I did not reread , but that is my 100 to 1 bet. Even if you replaced it. Wow that has to be it. But what do i know. I am just guessing based on experience.



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Offline eagleman

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Re: mysterious brake issue
« Reply #14 on: December 18, 2016, 11:49:53 AM »
Just what mudkicker said. Your master cylinder is leaking into your booster and would imagine the fluid has eaten it way through the diaphragm. Replace the booster and master cylinder. Had the very same exact problem with my 86 wagon. After replacing the entire braking system still had the same problem you are describing. Changed both the master and booster and all is good. Brakes work perfect now.
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Offline packotobacco

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Re: mysterious brake issue
« Reply #15 on: December 19, 2016, 02:33:29 AM »
I totally agree that the problem most likely lies in the MC Or Booster. My booster seems to be working fine though I can't seem to find many specifics on diagnosing a booster systematically. the check valve works and the membrane seems good according to the diagrams I've found, i don't really know what else to check on the booster so i did some testing on the master cylinder. Tried to level the MC but not even close and tried to bench bleed in car using plastic plugs with short return lines but kept getting bubbles . Bench bleed was successful out of car, solid when capped and Nov  bubbles or leakage so i reinstalled it with return lines still in and no bubbles in car. However once i reconnect to bleed the lines i get more bubbles in the larger reservoir even after bleeding all air from the lines. Does any one know if its normal for the MC to suck air back in from the lines. And even after working bubbles out for quite a while i still get bubbles in just the larger reservoir and it never diminishes. I've read i might fix this with teflon on all fittings it's cheap and sorta makes sense,  gonna get speed bleeder screws while I'm at it. I'm hoping this info is enough to tell me something definitive about either components badness. Since having replaced everything at least once already I'm looking for ways to be sure a parts bad before replacing. I'm told my testing proves the MC is ok. Is that true or is there something else to test? What can i do to test the booster fully? Preferably without burning gas for vacuum. Could the fittings really suck in air but never leak a drop? Seems impossible but I'm getting air from somewhere and it's keeping my MC from staying full. And lastly can a booster issue send pedal to floor with no stiffness or stopping power? Thanks again to the whole den, sorry for the long posts and thread. Just trying to be thorough

Offline mudkicker715

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Re: mysterious brake issue
« Reply #16 on: December 19, 2016, 10:29:19 AM »
Booster is working from what i hear. Teflon on those fittings is not a solution or a fix. Speed bleeders are useless. Also when i bleed the system i just gravity bleed it. Unless a line is pinched it will work awesomely.

I still say replace the master.



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Offline eagleman

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Re: mysterious brake issue
« Reply #17 on: December 19, 2016, 10:46:44 AM »
Well replacing the master cylinder may solve the problem . But if its leaking into the hydro its just a matter of time before it goes too. Best save yourself some time and just replace both now and be done with it.
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Offline packotobacco

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Re: mysterious brake issue
« Reply #18 on: December 28, 2016, 08:28:17 PM »
I just replaced the master in september with a brand new, not rebuilt, unit. I see nothing to indicate that it isn't working properly as sponginess could be air in the lines. When capped the master gets firm and doesn't sink at all. And just to clarify it doesn't leak at all, i had one leak but it was on and off the car in the same week and i never even turned it over. I have replaced my mc four times for four different reasons and my soft pedal always returns after like a week. I'm all for replacing the mc but i need to know I'm not wasting my time and money as i am short on both. May i ask why exactly you think it needs replaced? I'm unclear because you seem pretty positive but i don't understand what lead you to that conclusion

Offline AMC1

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Re: mysterious brake issue
« Reply #19 on: December 29, 2016, 02:39:16 PM »
I can easily see your frustrations. However if I read the thread correctly you know what the problem is - in that the MC is needing some refill of fluid. Sounds simple but you have to find where that fluid is going. I wouldn't be overly concerned about air entering the system as finding out how that fluid is getting out of the system. If you have a friend to help I would remove the tires & drums - bleed the system & then have him pump on those brakes. You then starting at the MC - with dry fingers follow every inch of fittings & lines. Good luck 
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Offline packotobacco

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Re: mysterious brake issue
« Reply #20 on: January 08, 2017, 05:37:27 PM »
Since last post I've gone over the lines completely and located that rear rubber line. The rubber section has no cracks or leaks even under pressure. I still can't find any issues anywhere in the lines calipers or cylinders. To be safe i checked the flares and found one that looked a bit ragged so i re-flared it and the two at the master. Afterwards i re bench bled and bled the lines  till all bubbles stopped and was pleased to see that the pedal got firm and i had no bubbles in the MC. Pumped the pedal and held it while starting and it sank. I understand that it's supposed to sink but i seem to lose all pressure with the vacuum assist on. When running i can feel pressure after a few pumps but it dissipates very quickly. When off the pedal gets firm again and i see no new bubbles. It seems as though the MC internal seals are allowing fluid past but only with the vacuum assist. I would swap it right now but  have changed it for this exact reason and had no improvement. I'm at a loss, is this definitely the MC? Could anything else cause this? Has anyone else experienced this and fixed it?

Offline 1985amceagle

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Re: mysterious brake issue
« Reply #21 on: January 12, 2017, 02:09:55 AM »
Reading through the thread I also agree with the others on the master cylinder ruling. The booster is mechanicay linked in between the pedal and master cylinder. And a diaphragm and vacuum helps increase the force you are applying with the pedal. So the fluid is either going past the seals in the master, or you have a leak somewhere. What brand master cylinder are you using? I've had bad luck with some store brand items one was a hydraulic clutch master cylinder, at times the clutch pedal would be ok, other times it would go straight to the floor. Put on three of the same store brand before switching to a name brand, which havent had any trouble with since. I would check what the warranty is, maybe your parts supplier will get you another one, or credit for another brand depending on if you are in the warranty period yet. Also have run into a bad batch of parts before, so even name brand stuff can fail prematurely.
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Offline AMC1

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Re: mysterious brake issue
« Reply #22 on: January 13, 2017, 11:04:15 AM »
I thought you were losing fluid but if you're not then like the others say you're probably best in replacing that MC. Good luck.
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Offline packotobacco

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Re: mysterious brake issue
« Reply #23 on: January 14, 2017, 11:15:55 PM »
 So yesterday i capped the ports to the master cylinder and put some serious pressure on the pedal. It was solid enough but i thought i felt it sinking super slow and everyone seemed to be sure it was the master so i replaced it again. Dug out my receipt and used the warantee, bench bled carefully so as not to hurt the seals, then I capped the ports and connected it to the booster. Pumped the pedal and held while starting and sank and stopped 1" off the floor exactly like it should. So then i bled the lines one end at time just in case. Spent a long time bleeding after bubbles stopped again just in case. Held the pedal while starting again and it sank almost to floor with little pressure. Just like before with engine running i only get any resistance from the pedal after i pump it up and then it fades to bottom again. NO leaks anywhere, NO bad seals,NO bad booster, NO fluid loss, but still NO pressure. :banghead: HELP!

Offline packotobacco

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Re: mysterious brake issue
« Reply #24 on: January 15, 2017, 04:42:32 PM »
I forgot to mention that when i was pumping the pedal my rpm's climbed slightly with each press. If i remember correctly thats normal but thought I'd ask

Offline AMC of Houston

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Re: mysterious brake issue
« Reply #25 on: January 15, 2017, 07:32:32 PM »
It is the booster.   Your rpm increase tells me something's not right with it (leaky diaphragm or some other internal vacuum leak.
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Offline AMC of Houston

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Re: mysterious brake issue
« Reply #26 on: January 15, 2017, 07:43:21 PM »
Get a vacuum pump and see if the booster holds vacuum.
« Last Edit: January 15, 2017, 07:44:03 PM by AMC of Houston »
George G.
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Offline packotobacco

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Re: mysterious brake issue
« Reply #27 on: January 16, 2017, 02:12:53 PM »
I hooked my mightyvac to to the booster and it held vacuum. And after turning the engine off i get 2-3 vacuum assisted pumps even hours later. I was under the impression that booster failure causes hard pedal. Could you please explain how the booster could cause my soft pedal.

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Re: mysterious brake issue
« Reply #28 on: January 16, 2017, 09:03:49 PM »
Afraid I can't answer that one (not that familiar with booster guts).   I just know I had a similar issue on my Sundancer, and a new booster cured it.
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Offline packotobacco

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Re: mysterious brake issue
« Reply #29 on: January 17, 2017, 02:11:41 PM »
So i checked my pedal last night and found that air had worked up into the master. I bled the lines three different ways and got pure fluid for a long time on each bleeder. Air must have come from the lines so I'm gonna try purge the air from the top end by applying vacuum to the reservoir. It's the only method i haven't tried yet so wish me luck.

Offline packotobacco

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Re: mysterious brake issue
« Reply #30 on: January 21, 2017, 12:50:13 PM »
Vacuum thing didn't work so i tried the super long hose from bleeders to reservoir thing. 20' was plenty long enough to route to the drivers seat along the way. Did that so i could kink the hose while releasing the pedal to simulate a closed bleeder. Doing this made it very apparent that air was seeping past the threads on every bleeder, cured that with Teflon tape. When i got to the front right line i got down to super tiny bubbles but they wouldn't stop so i tried the pump and crack method and got endless stream of larger bubbles. Under that method it couldn't be threads or hose letting air in. Is there a spot that could suck air in at low pressure but not leak under the much higher pedal pressure? Btw fluid level doesn't drop but it raises when more bubbles appear

Offline AMC1

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Re: mysterious brake issue
« Reply #31 on: January 23, 2017, 04:00:42 PM »
I've never had bleeder screws leak once they were tightened down. I sure wouldn't trust the brakes to Teflon tape. Rebuilt wheel cylinders which include new bleeder screws are inexpensive maybe $5-8. Calipers of course are more expensive. I just can't imagine all four leaking.
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Offline mudkicker715

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Re: mysterious brake issue
« Reply #32 on: January 23, 2017, 04:51:52 PM »
Teflon tape does not belong there ever for sealing purposes. You have issues that are not being said somehow.



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Offline packotobacco

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Re: mysterious brake issue
« Reply #33 on: January 24, 2017, 02:18:57 PM »
The teflon has nothing to do with my issue. Only used it to keep air from sucking in on release as i had no helper at the time and the mightyvac kept sucking air past the threads. That said i made a motive bleeder and will post results after i finish.

Offline mudkicker715

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Re: mysterious brake issue
« Reply #34 on: January 24, 2017, 03:34:28 PM »
For bleeding brakes i only gravity bleed. Meaning open the fartest point on back till only a stream comes out than the closer point. Same on front. This works well even on my navigator. Unless a rubber hose is pinched like on the previous vechicle i mentioned.



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Offline eagleman

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Re: mysterious brake issue
« Reply #35 on: January 24, 2017, 06:03:59 PM »
Have you considered using a pressure bleeder. I have one and you pressurize it to sixty pounds  and it has a cap that fits over the master cylinder. It will for sure bleed your brakes and any leaks will also for sure show up. The one I have is made by Wagner and are rather pricy but you might find on for rent and any tool rental place or some auto parts store that also rent tools.
Turkeys walk.Eagles fly!!!

Offline packotobacco

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Re: mysterious brake issue
« Reply #36 on: January 27, 2017, 07:20:00 PM »
I just built my own with a $10 sprayer can, a 1/8 hose fitting and an air nozzle with a rubber tip. As for psi I just stick the nozzle in a cheapo gauge i keep around and count the pumps. Total cost twenty bucks but thats w/o the gauge and master cylinder cap. Took mine from my first rebuilt unit that didn't work and drilled a hole just off center so i could still use the wire for the cap. I was told 30 psi but I'll try 60 if 30 doesn't work. The spray can will do just air or you can fill it with brake fluid to avoid refilling. Can't wait to test it out, fingers crossed.

Offline AMC1

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Re: mysterious brake issue
« Reply #37 on: January 28, 2017, 04:10:23 PM »
I use to use air pressure until my canister exploded & I had brake fluid everywhere. Your paint job will not like it. I've never had  a problem since with simply putting a bleeder line in a jar with fluid. Air can't back up. If you have an opening somewhere else that's a problem.
1976 gremlin
pair of 1983 SX4's sports
1946 Cushman step-thru

Offline packotobacco

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Re: mysterious brake issue
« Reply #38 on: April 05, 2019, 05:44:55 AM »
Hi again finally back for more punishment.had to give up for awhile because I had to move. No room at new place so it's been in storage, but now I have a driveway again so I'm back at it. The pressure bleed didn't work so I recently gave up and handed it over to a highly recommended shop. $500 dollars and two months later he gave up and handed it back. But supposedly he got rid of the bubbles completely. And he definitely improved the stopping power, but only a little bit. So currently a full depress engages the drums quite well while running but not the discs. I'm thinking it must be a pedal / rod travel issue, as that could explain the weak bleeding pressure and thus why I could never clear all the bubbles AND the soft pedal while running AND the drums working but not discs. Does that make sense or am I way off base? I did check the booster pushrod adjustment but I don't remember comparing the length of the rod that connects the rear of the booster to the pedal. Can anyone get me a measurement for that? Thank you all for your help and info, without this forum I'd be lost and have to scrap an otherwise good running American treasure

Offline packotobacco

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Re: mysterious brake issue
« Reply #39 on: July 03, 2021, 07:01:56 PM »
Hi there I know this topic has been dead for a while but I finally have some answers so I figured I'd put them down. I recently took my eagle to a shop that's had at least some experience in working on them. After replacing some of my brake lines my constant bubble issue finally disappeared, thank the eagle Gods. Then they replaced most of my exhaust and found a leak at the exhaust manifold. I'll explain how me and countless cans of starter fluid managed to miss that, later. Got in some testing in the parking lot and had a high firm pedal. On the way home as some of the computer stuff kicked in, my vacuum dropped off a bit and my pedal got spongy. Got home and checked vacuum and lines reconnected one that the mechanics had capped. Checked the timing and spark plugs and everything seemed perfect, However, IT STILL RAN LIKE CRAP AND LOST BRAKES UNDER LOAD.

Obviously, something must have still been wrong. I busted out the mental thesaurus and tried every search term I could cobble together to find information about timing a 258 engine. Eventually I decided to pull the distributor and realign everything manually. Found TDC with a flashlight through number one sparkplug hole, checked valves through the oil fill cap.

Here's where it gets interesting, I went to reinstall the distributor and found the number one cylinders rotor position, UNDER THE SPARK CABLE FOR CYLINDER NUMBER SIX. That made absolutely no sense to me until I realized that, if the distributor is 180° out the engine won't fire on number one cylinder but number six will still fire as it is on the compression stroke at that time and you can turn the dizzy almost enough to time it to number six when it's reversed. Which is why my timing sounded worse the closer I got to the timing mark, if I had put the inductor for my timing light on the number 6 cable I may actually have been able to time it, but that would have rendered the timing mark useless.

Suddenly every problem I've had for years has a single explanation that makes sense, my vacuum testing for the brakes was worthless because the idle had to be tuned so high that I would have had full vacuum with a hole in the manifold, I never found the vacuum leak because the mixture was so rich it was a drop in the bucket, the bubbles weren't the cause of my spongy pedal they may actually have been a symptom, ie excessive vacuum due to idle, and my computer actually keeps my engine from trying to die now instead of killing it. Yay!

I'd like to say a quick and final thank you to not only the members who have helped me on this post but all the members whose information has helped me along the way seriously could not have done it without you.

BTW, if you have questions I'm on the site a lot more than I post so feel free to ask.

Offline AMC1

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Re: mysterious brake issue
« Reply #40 on: July 23, 2021, 11:08:36 AM »
Now that you seem to have solved the problem I'd like to know How high off the floor board is your brake pedal with the engine running & having successfully applied the brakes.
1976 gremlin
pair of 1983 SX4's sports
1946 Cushman step-thru

 

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