swampedout Posted November 9, 2019 Share Posted November 9, 2019 Hey folks, I've bought 2 brake boosters for my '84 250. I should have read the door card more closely because my GVWR is over 8500 (its rated 8600). My question, before I order my 3rd booster is if anyone knows if the studs where the master cylinder mounts the brake booster on the Over 8500 GVWR booster are wider apart than the Under 8500 booster? Thanks Link to comment Share on other sites More sharing options...
swampedout Posted November 9, 2019 Author Share Posted November 9, 2019 And follow-up question: Rockauto has the ACDelco reman booster. Would anyone recommend this product or should I search around some more? Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 9, 2019 Share Posted November 9, 2019 According to my post here in the Hydroboost Brake Conversion thread: So, it looks to me that up through 1986, inclusive, the master cylinders for trucks up to 8500#'s had the narrow bolt spacing and trucks above that had the wide spacing. But some time, probably in '87, the break point changed such that even up to and including F350's had the narrow spacing. You didn't say what the problem has been for the first two boosters you bought. But, does the above answer your question? As for AC/Delco, I think their stuff is good, and I'd buy one if it was an option. Link to comment Share on other sites More sharing options...
swampedout Posted November 10, 2019 Author Share Posted November 10, 2019 According to my post here in the Hydroboost Brake Conversion thread: So, it looks to me that up through 1986, inclusive, the master cylinders for trucks up to 8500#'s had the narrow bolt spacing and trucks above that had the wide spacing. But some time, probably in '87, the break point changed such that even up to and including F350's had the narrow spacing. You didn't say what the problem has been for the first two boosters you bought. But, does the above answer your question? As for AC/Delco, I think their stuff is good, and I'd buy one if it was an option. Thanks Gary, that answers my question. The problem with the first two was that the studs did not match up with the master cylinder. At first, I assumed it was another bad autozone part but it turns out I requested the wrong part. None of the brick-n-mortar parts stores carry the 8500+ booster apparently. Link to comment Share on other sites More sharing options...
swampedout Posted November 14, 2019 Author Share Posted November 14, 2019 Thanks Gary, that answers my question. The problem with the first two was that the studs did not match up with the master cylinder. At first, I assumed it was another bad autozone part but it turns out I requested the wrong part. None of the brick-n-mortar parts stores carry the 8500+ booster apparently. so the 8500+ booster and master cylinder have studs set wider apart. Rockauto had a delay on the ACdelco units so I picked up a junkyard booster which surprise does not hold vacuum. I can hear it hissing in the cab when the pedal is depressed. So now I order and wait. Link to comment Share on other sites More sharing options...
swampedout Posted November 14, 2019 Author Share Posted November 14, 2019 so the 8500+ booster and master cylinder have studs set wider apart. Rockauto had a delay on the ACdelco units so I picked up a junkyard booster which surprise does not hold vacuum. I can hear it hissing in the cab when the pedal is depressed. So now I order and wait. Scratch that. Apparently Rockauto doesny have any 8500+ boosters. Anyone know where I can find a reman unit before I go back to the junkyards? Thanks Link to comment Share on other sites More sharing options...
swampedout Posted November 14, 2019 Author Share Posted November 14, 2019 Scratch that. Apparently Rockauto doesny have any 8500+ boosters. Anyone know where I can find a reman unit before I go back to the junkyards? Thanks For some reason, the parts stores all have Boosters for 1984 F350s. According to what I think I learned from the hydroboost conversion thread, these should match up with a 1984 F250 MC with a GVWR of 8500+ but I don't understand why the catalogues wouldnt list my truck as compatible. I hate being a nervous nancy about this stuff but I am talking about buying my 4th booster so I want to make sure I get it right. Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 14, 2019 Share Posted November 14, 2019 For some reason, the parts stores all have Boosters for 1984 F350s. According to what I think I learned from the hydroboost conversion thread, these should match up with a 1984 F250 MC with a GVWR of 8500+ but I don't understand why the catalogues wouldnt list my truck as compatible. I hate being a nervous nancy about this stuff but I am talking about buying my 4th booster so I want to make sure I get it right. If you look at our page here: Documentation/Driveline/Brakes and then the Master Cylinders & Boosters tab and then the Part Numbers tab you'll find the table below, which shows that an 84-86 F250 above 8500 GVWR takes E4TZ 2005-B. And if you look a bit farther down you'll see that an 84 - 86 F350 also takes E4TZ 2005-B. So, in my book the only catalog that counts, Ford's Master Parts Catalog, says it is compatible. Link to comment Share on other sites More sharing options...
swampedout Posted November 14, 2019 Author Share Posted November 14, 2019 If you look at our page here: Documentation/Driveline/Brakes and then the Master Cylinders & Boosters tab and then the Part Numbers tab you'll find the table below, which shows that an 84-86 F250 above 8500 GVWR takes E4TZ 2005-B. And if you look a bit farther down you'll see that an 84 - 86 F350 also takes E4TZ 2005-B. So, in my book the only catalog that counts, Ford's Master Parts Catalog, says it is compatible. Gary you are a blessing! Its still a hard item to find but I might have luck with the "F350" part. Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 14, 2019 Share Posted November 14, 2019 Gary you are a blessing! Its still a hard item to find but I might have luck with the "F350" part. Good luck! Link to comment Share on other sites More sharing options...
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