Gary Lewis Posted June 25, 2020 Share Posted June 25, 2020 I am planning on running the newer F-superduty hydroboost booster, I will check the spacing of the masters to the boosters bolt patterns. I will use whatever master I can find that fits the booster. I am not scared of bending up a new brake line. I am hopeful the 1991 F250 master will bolt up to the about 1994 F-Superduty hydroboost booster and the 1991 F250 lines hook up to the stock propotioning valve. I do not recall why I thought the proportioning valve needed to be changed. Perhaps because I have a 10.25 rear axle already and the d44hd style knuckles modified and installed on the front d44 ttb. I think it might help make the brakes more even. However, I need to research everything a bit more and especially the proportioning valve differences yet. Just seemed since I had f250 brakes I would need the f250 proportioning valve. Yes, I said it incorrectly. The booster bolts to the cab and the master bolts to the booster. But in my case the '95 hydroboost unit wouldn't take the '90 master I had. The bolt spacing was wrong. But the '95 F450's master fit. And then the '90 F250 lines went perfectly from that to the '85 proportioning valve. As for the proportioning valve, this snippet from our page (Documentation/Driveline/Brakes) says there were several different ones, but your Bronco should have the same one as Big Blue. So the later lines should fit. BUT, I can't tell you that it works as I don't have BB on the road yet. Link to comment Share on other sites More sharing options...
IDIBronco Posted June 25, 2020 Author Share Posted June 25, 2020 Yes, I said it incorrectly. The booster bolts to the cab and the master bolts to the booster. But in my case the '95 hydroboost unit wouldn't take the '90 master I had. The bolt spacing was wrong. But the '95 F450's master fit. And then the '90 F250 lines went perfectly from that to the '85 proportioning valve. As for the proportioning valve, this snippet from our page (Documentation/Driveline/Brakes) says there were several different ones, but your Bronco should have the same one as Big Blue. So the later lines should fit. BUT, I can't tell you that it works as I don't have BB on the road yet. Well, as soon as I get ambitious this morning I am going to head out and get started investigating the options on the brakes. Nothing is really better for me to know what's what then laying parts side by side and comparing. More pictures to follow today. I am trying to document this project in ways that will be helpful to others. I am no expert. If anyone needs a different angle, or something else pictured just let me know. The pictures make sense to me, but I am seeing it in person. I may not be able to answer questions, but I will say when i do not know. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted June 25, 2020 Share Posted June 25, 2020 ..........(Documentation/Driveline/Brakes) says there were several different ones, but your Bronco should have the same one as Big Blue. So the later lines should fit. BUT, I can't tell you that it works as I don't have BB on the road yet. I don't think this is correct The Bronco and the 150 are the same. The 250/350 have another combination valve (pull v/s push, to bleed) I remember Chris pointing this out because his 250 didn't work the way the manual told him. At least the Bronco's didn't get that leveling arm on the rear axle. Link to comment Share on other sites More sharing options...
IDIBronco Posted June 25, 2020 Author Share Posted June 25, 2020 Well, as soon as I get ambitious this morning I am going to head out and get started investigating the options on the brakes. Nothing is really better for me to know what's what then laying parts side by side and comparing. More pictures to follow today. I am trying to document this project in ways that will be helpful to others. I am no expert. If anyone needs a different angle, or something else pictured just let me know. The pictures make sense to me, but I am seeing it in person. I may not be able to answer questions, but I will say when i do not know. Ok. The bronco booster and master are now out. I even threw the hydroboost into the pedal bracket for good measure. it looks like my pin location modification has an alignment that 'should' work, assembly and test drive will be the judge. The F-Superduty master. I see the casting number on the hydroboost is an e8 so perhaps it is from a bit older truck than I recalled. The f250 master It looks like the master to booster mount on all 3 of my master cylinders will work (according to tape measure, so not 100% sure, but close enough to make work if not perfect). So now the question arises of what master to run. I had been running a stock bronco master with the 10.25 and d44hd style brakes. The f250 master cylinder which has a plastic reservoir (I was mistaken, I had thought it was the old style all cast metal unit, but I must have been thinking of the 86f350 truck), the stock bronco (unknown diameter as it isn't marked externally that I could find), or run the F-Superduty master which is 1 5/16". I would also think the upgraded size would result in a much lower pedal effort requirement to stop. I would anticipate a few hitting the windshield type braking events in the learning process to retrain my muscle memory for braking... always an exciting thought. Are there any downsides to running a 1 5/16" master cylinder? I would imagine the added volumetric size of the master would require less pedal travel, to compensate for adjusted pin length of the modified pedal for the hydroboost. I wonder if the F-Superduty master parts will be harder to come by in the future should I need a new master or a rebuild? Pretty hard to speculate on that, but I would be pretty sure they would be more expensive than a higher volume production model (like the 1 1/8"). Anyone with experience/opinions please speak up as I have a couple days before the parts get here that allow reassembly to occur. I am leaning towards the 1 1/8" bore of the F250 since I have brakes that match that trucks design, but I would like to upgrade to rear discs eventually not sure what the recommended master cylinder for that would be. Is there any reason a person couldn't take the stock brake lines to the master cylinder and just cut the ends off and reflare the proper size fitting on that you need. It seems like a pretty simple solution to the wrong size fitting to me. If I mess the line up it is easy enough to bend and double flare a new line up. Link to comment Share on other sites More sharing options...
IDIBronco Posted June 25, 2020 Author Share Posted June 25, 2020 I don't think this is correct The Bronco and the 150 are the same. The 250/350 have another combination valve (pull v/s push, to bleed) I remember Chris pointing this out because his 250 didn't work the way the manual told him. At least the Bronco's didn't get that leveling arm on the rear axle. I guess this is the type of issue I was remembering that had me thinking I needed to swap the valve on the frame. Link to comment Share on other sites More sharing options...
Gary Lewis Posted June 25, 2020 Share Posted June 25, 2020 Ok. The bronco booster and master are now out. I even threw the hydroboost into the pedal bracket for good measure. it looks like my pin location modification has an alignment that 'should' work, assembly and test drive will be the judge. The F-Superduty master. I see the casting number on the hydroboost is an e8 so perhaps it is from a bit older truck than I recalled. The f250 master It looks like the master to booster mount on all 3 of my master cylinders will work (according to tape measure, so not 100% sure, but close enough to make work if not perfect). So now the question arises of what master to run. I had been running a stock bronco master with the 10.25 and d44hd style brakes. The f250 master cylinder which has a plastic reservoir (I was mistaken, I had thought it was the old style all cast metal unit, but I must have been thinking of the 86f350 truck), the stock bronco (unknown diameter as it isn't marked externally that I could find), or run the F-Superduty master which is 1 5/16". I would also think the upgraded size would result in a much lower pedal effort requirement to stop. I would anticipate a few hitting the windshield type braking events in the learning process to retrain my muscle memory for braking... always an exciting thought. Are there any downsides to running a 1 5/16" master cylinder? I would imagine the added volumetric size of the master would require less pedal travel, to compensate for adjusted pin length of the modified pedal for the hydroboost. I wonder if the F-Superduty master parts will be harder to come by in the future should I need a new master or a rebuild? Pretty hard to speculate on that, but I would be pretty sure they would be more expensive than a higher volume production model (like the 1 1/8"). Anyone with experience/opinions please speak up as I have a couple days before the parts get here that allow reassembly to occur. I am leaning towards the 1 1/8" bore of the F250 since I have brakes that match that trucks design, but I would like to upgrade to rear discs eventually not sure what the recommended master cylinder for that would be. Is there any reason a person couldn't take the stock brake lines to the master cylinder and just cut the ends off and reflare the proper size fitting on that you need. It seems like a pretty simple solution to the wrong size fitting to me. If I mess the line up it is easy enough to bend and double flare a new line up. I will be surprised if the F250 master will fit the hydroboost. My '90 F250 master wouldn't. The one that fit looks exactly like yours - 1 5/16". Where did you find the ID # on the hydroboost unit? Mine is installed and I didn't see it with a quick look. But if I knew where to look I might confirm what its # is. Link to comment Share on other sites More sharing options...
Gary Lewis Posted June 25, 2020 Share Posted June 25, 2020 I don't think this is correct The Bronco and the 150 are the same. The 250/350 have another combination valve (pull v/s push, to bleed) I remember Chris pointing this out because his 250 didn't work the way the manual told him. At least the Bronco's didn't get that leveling arm on the rear axle. I guess this is the type of issue I was remembering that had me thinking I needed to swap the valve on the frame. I am almost certain that your later lines from the parts truck will fit the master and go into your proportioning valve. I have an '85 F250HD proportioning valve, '90 F250HD lines, and '95 F450 master and hydroboost unit, and it all bolted together perfectly. But, don't forget to pull the switch on the front/bottom of the master and plug the hole. Link to comment Share on other sites More sharing options...
IDIBronco Posted June 25, 2020 Author Share Posted June 25, 2020 I will be surprised if the F250 master will fit the hydroboost. My '90 F250 master wouldn't. The one that fit looks exactly like yours - 1 5/16". Where did you find the ID # on the hydroboost unit? Mine is installed and I didn't see it with a quick look. But if I knew where to look I might confirm what its # is. On the top right side (from front of truck) behind the port. Link to comment Share on other sites More sharing options...
Gary Lewis Posted June 25, 2020 Share Posted June 25, 2020 On the top right side (from front of truck) behind the port. Looks like we have the same one. Here's mine. You'll see we have the same ID #'s: E8TA 2B560-AA. But the #'s after that are different, although I don't know what they represent. Date codes? Link to comment Share on other sites More sharing options...
IDIBronco Posted June 25, 2020 Author Share Posted June 25, 2020 I am almost certain that your later lines from the parts truck will fit the master and go into your proportioning valve. I have an '85 F250HD proportioning valve, '90 F250HD lines, and '95 F450 master and hydroboost unit, and it all bolted together perfectly. But, don't forget to pull the switch on the front/bottom of the master and plug the hole. I stand corrected. F-Superduty on left F-250 on right. Gary is 100% correct the 1991 f250 master will not fit. The fittings look to be the same so I can probably rob the brake lines from the f250 to make it work. It also makes the decision on what master to work that much easier. Link to comment Share on other sites More sharing options...
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