viven44 Posted August 17 Share Posted August 17 Yes very true on both! Well the new booster did reduce the variables I was worried about. I always thought it was the booster but when I realized it wasn’t all of it I had the conviction to go after the next one which is the pushrod length. I have always errored on the side of small as I would rather have more pedal travel than dragging brakes but this morning I went ahead and 3D printed the jig to make a precise adjustment. My brakes are still 'soft' but thats probably what I get for using $15 Raybestos shoes and pads. It really firmed up the pedal though. I was at 0.95” and I changed it to 0.98”. From 78 Truck Shop Manual Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 17 Share Posted August 17 Well the new booster did reduce the variables I was worried about. I always thought it was the booster but when I realized it wasn’t all of it I had the conviction to go after the next one which is the pushrod length. I have always errored on the side of small as I would rather have more pedal travel than dragging brakes but this morning I went ahead and 3D printed the jig to make a precise adjustment. My brakes are still 'soft' but thats probably what I get for using $15 Raybestos shoes and pads. It really firmed up the pedal though. I was at 0.95” and I changed it to 0.98”. From 78 Truck Shop Manual That's cool! If we had a page to share 3D plans would you share that? Link to comment Share on other sites More sharing options...
viven44 Posted August 17 Share Posted August 17 That's cool! If we had a page to share 3D plans would you share that? Absolutely, in fact you can download from here https://www.tinkercad.com/things/d9m2WgRlwyW-brake-booster-adjustment-jig?sharecode=e7ODS2c4UAyOEiNQSTgsCIijfWua1H6tCsFSNFyDPh8 Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 17 Share Posted August 17 Absolutely, in fact you can download from here https://www.tinkercad.com/things/d9m2WgRlwyW-brake-booster-adjustment-jig?sharecode=e7ODS2c4UAyOEiNQSTgsCIijfWua1H6tCsFSNFyDPh8 Vivek - If it is ok I'm going to download that file and make it available directly on here instead of through TinkerCAD. The reason being that people have to sign up to TinkerCAD to download it and this will make it easier. And it also ensures that if something happens on TinkerCAD we have it. Is that ok? And I'm going to use the diagram out of a Bullnose FSM just to assure people that those are the right dimensions. But, they are. Link to comment Share on other sites More sharing options...
viven44 Posted August 17 Share Posted August 17 Vivek - If it is ok I'm going to download that file and make it available directly on here instead of through TinkerCAD. The reason being that people have to sign up to TinkerCAD to download it and this will make it easier. And it also ensures that if something happens on TinkerCAD we have it. Is that ok? And I'm going to use the diagram out of a Bullnose FSM just to assure people that those are the right dimensions. But, they are. Gary, of course. It is open source! I did observe that on my 78 Brake booster the 2 15/16 dimension was a little too big to fit in between the studs. I had to rotate the jig to use it. If I had to redo it I would shorten that side just a bit. The 2 15/16 was right on the money as-printed Appears to have the same problem on the bullnose brake booster based on a quick eyeball This is old cylinder from the 78. Clearly too big on it Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 17 Share Posted August 17 Gary, of course. It is open source! I did observe that on my 78 Brake booster the 2 15/16 dimension was a little too big to fit in between the studs. I had to rotate the jig to use it. If I had to redo it I would shorten that side just a bit. The 2 15/16 was right on the money as-printed Appears to have the same problem on the bullnose brake booster based on a quick eyeball This is old cylinder from the 78. Clearly too big on it Do you want to revise the drawing with the smaller width and then send me the file? Link to comment Share on other sites More sharing options...
viven44 Posted August 17 Share Posted August 17 Do you want to revise the drawing with the smaller width and then send me the file? Yes let me revise and print and test it … Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 17 Share Posted August 17 Yes let me revise and print and test it … I have the page up: Documentation/3D Printing/Brake Booster Pushrod Gauge. And the illustration from the FSM is on there, as shown below. But it shows that the surface of the booster isn't even between the studs. So you'll want to ensure you catch the high spot. Link to comment Share on other sites More sharing options...
viven44 Posted August 17 Share Posted August 17 I have the page up: Documentation/3D Printing/Brake Booster Pushrod Gauge. And the illustration from the FSM is on there, as shown below. But it shows that the surface of the booster isn't even between the studs. So you'll want to ensure you catch the high spot. Yes I saw that. On my reman 78 booster though that profile is slightly different than the core I turned in yesterday. There is a “bump” closer to the center and in ford style I’ll guess there were small variations between applications. The incoming bore on the cylinder will also need to be measured vs the old one. That’s why I printed close to 0.98” so it will error on the small side. I’ll measure between the holes on the cylinder and get it as close as possible so it will fit but not be too small. Link to comment Share on other sites More sharing options...
viven44 Posted August 17 Share Posted August 17 I have the page up: Documentation/3D Printing/Brake Booster Pushrod Gauge. And the illustration from the FSM is on there, as shown below. But it shows that the surface of the booster isn't even between the studs. So you'll want to ensure you catch the high spot. Well I have good news. Instead of assuming the bullnose and dentside are the same I decided to check the gauge on the 86 F250 parts truck which is a highly original truck and assumed all original parts The gauge works as-is on a bullnose 3/4 ton. I can’t say if it’s a 1/2 vs 3/4 ton difference or if it’s dentside 1/2 ton vs bullnose 3/4 ton but my 78 bronco needs 2 9/16 instead of 2 15/16 Pics below from the 86 F250 3/4 ton parts truck Link to comment Share on other sites More sharing options...
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