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Alright you guys someone did a rear disc conversion swap on my bronco before I got it and they didn't do the greatest job on it. So after I got a hole in a brake line I replaced the calipers, both lines that go to the calipers and the line going across the axle. For some reason im getting brake fluid to the calipers with no air but there is no pressure to the brake pedal. Would the problem be the master cylinder now? Thanks
 

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So far the problem would be lack of information. Pictures would help a lot. How did a hole in a brake line lead to replacing calipers? What type of calipers are they? How did you bleed them? Is the stock proportioning valve still in the brake system? Let's start with that info and go from there.
 

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Discussion Starter #3
The reason I replaced the caliper's was due to the old ones haveing torn seals and being in rough shape, so I got the same calipers from a junk yard. They came off an 87 lincoln continental. After I put everything back together I had someone pump the brakes then hold down the pedal when it got tighter and I loosened the valve on rear passenger side then made my way to the rear driver side then and filling the master cylinder up in between. After doing this a few times it didn't help. And also whoever did the conversion left the stock master cylinder on it for drums which has the small resevoir for the rear and large for the front. I was gonna replace it before but it has worked for me since I've the truck for the last 5 years with the same setup. Any suggestions?
 

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You'll need the dual reservoir master cylinder and maybe an adjustable proportioning valve...

If and when you change the MC make sure "bench bleed" it first before you put in on otherwise you'll be there until retirement trying to get a pedal...if you know what I mean...

Then re-bleed the system and re-adjust the reear brakes you should be good to go....


Good Luck ~ :thumbup
 

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You'll need the dual reservoir master cylinder and maybe an adjustable proportioning valve...

If and when you change the MC make sure "bench bleed" it first before you put in on otherwise you'll be there until retirement trying to get a pedal...if you know what I mean...

Then re-bleed the system and re-adjust the reear brakes you should be good to go....


Good Luck ~ :thumbup
The stock MC IS dual reservoir, although not specifically designed for rear disk brakes.

I've used a vac bleeder with some degree of success.
Might be worth a try to get out stubborn air in the lines.
Harbor freight sells a cheap kit.
 

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It is quite possable to have fluid PRESSURE at the caliper but not have enough fluid VOLUME to properly operate the piston. That is why there are distinctly different M/C's for simular vehicles that have all drums, front disk/rear drums, and those that have 4-wheel disks.

A bit about bleeding brakes that have a modern dual-type M/C;

It aint nessessary to start off by"pumping the pedal" before attempting to expell air from the lines, and/or wheel cyl's, and/or the calipers. In fact, under certain circumstances you might find that doing so is counterproductive. Reason is...assuming that there's no air in the M/C to disrupt flow, gravity alone will cause fluid to flow from the reservoir, through the M/C, though the lines, and into the cylinder (or caliper). And traveling along with the fluid, goes the air.
About all you gotta do here is fill the reservior, leave the lid loose, loosen the bleeder screw (start at the R/R wheel), watch the fluid drip become a stream, and tighten the bleeder after it is apparent that there aint no more air bubbles coming out. Refill the reservior and repeat with the L/R......then on to the R/F and L/F.
If you think that there is a little air left behind somewhere after all that, THEN go ahead with the pump 'n bleed thing. If you try it first though, you stand a good chance of the M/C sucking air backwards and leaving it upsteam and/or in places that are hard to get it out of. Pressing hard on the break pedal with a lot of air still in the system can/will often cause the proportioing valve to trip to one side too, which in turn causes the yellow "Check Brakes" or "ABS" light to come on. And if the valve trips, it cuts off fluid untill it's reset, so now you aint bleeding squat untill you fix that problem.

Aint saying that my way is the only way to do it. I aint even saying that my way is the best way to do it. Thing is though, what I tried to articulate here is how I was taught to do it while attending a brake school put on by Wagner-Lockhed way back when. That, and it has always worked for me....first time, every time....since 1968.

Hope this helps someone.

DGW
 

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May be silly but!

Just thought I would ask are your bleed screws at the top of the caliper, if not it will not bleed! If it stopped fine with the mc you have then why change it! You will not get pressure at the calipers if they are upside down because there is a huge air pocket! Just a thought!
 

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Well that may be the cause of the problem, check around and compare OEM MC numbers and see if there's any difference of application etc.

What about a pistol grip, vacuum style self bleeder......IIRC you can pick them at Harbor Freight for a decent price....I borrowed my neighbors and it worked great.....

Good Luck ~ :thumbup
 

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I always gravity bleed brakes like DGW said. it works great and leaves very little air to pump out.
but it sounds like you have a leak. clean all of your connections with brake cleaner making sure theres no fluid visable, pump it several times and look for fluid.
 

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Had a similiar problem with my disk brake upgrade. Started to replace calipers, brake pads and MC and no luck. Actually thought about going back to drums wich was a joke. At the end the only thing to replace was the booster but was a question of getting one for a bronco or F350. Ordered one for a F350 and took care of all of my issues and truck stops with no problems. Hope this info helps.
 

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If these are rear Ford calipers, you may need to adjust them. I would refer to the manual for the vehicle the brakes were originally equipped in and follow the procedure it recommends.
 

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id say change your proportioning valve. one made for a disc set, and start gravity bleeding from there.
 

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Discussion Starter #13
Ok well I figured out the problem with a special thanks to 78BEAST. I appreciate the help and ideas from everyone. I felt really dumb when I realized what I had done. I was in such a hurry to get my bronco back up and running that I didn't pay much attention. Now that I replaced most of the most of the rear brake system(calipers and lines the right way) it works better than ever. Again I appreciate the help from everyone. Thanks
 

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If these are rear Ford calipers, you may need to adjust them. I would refer to the manual for the vehicle the brakes were originally equipped in and follow the procedure it recommends.
Explain to me how to "adjust" a disc brake caliper.
 

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BS
 

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Not BS. Why do you think I asked the OP whether he adjusted them or not? Ford seems to feel so strongly that rear disc calipers should be adjusted that they made brake calipers with adjusters in them. Funny thing, GM and Kelsey-Hayes and Bendix did too. Go figure.
 

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You can return back to Mount Olympus now.
 

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Glad to hear it is solved!

I have been working on cars for 30 years! I always say when I find out I have done that, that I will never do that again! NEWS FLASH don't say never, I have probably done it 3 or 4 times! Anyhow glad to hear you have brakes! Now all I have to do is figure out if I have a frame under all the rust!
 
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