When I first built my 72, the rear shoes were worn out so I rebuilt the rear brakes with new shoes, adjusters, wheel cylinders, etc. and turned the drums. I drove it a few times like that and while it didn't stop like a new truck, it was not bad. I put the complete front end from a 76 under my 72 to convert to disk brakes and it seems as though it is harder to stop than it was before the swap. It feels like a truck without power brakes. It will stop ok, but it takes a lot of effort. My first thought was that I had a bad power booster so I replaced that but still change. I put new rotors, pads, brake lines, and a new master cylinder on the truck when I did the swap so I figure those can be eliminated as the problem. The calipers from the 76 looked as if they had been replaced not long before the truck ended up in the junkyard and the pistons were not stuck so I did not replace them. I'm down to a couple of things that I think might be the problem and was wondering if anyone had any thoughts on this. The two things I have my doubts about are:

1) The 390 in my truck pulls about 16" of vacuum at idle. Is this enough for the power booster???

2) Could the calipers be the problem even though I checked them and know the pistons were not sticking when I put them on.

If anyone has run into this problem before or has any ideas on what might be causing the problem please let me know. Thanks!

 

Did you change the proportioning valve TOO?
Are the rear brakes adjusted just off rubbing the drum?
Dennis



Please Don't Ask Me Any Tough Questions As:
"I'm Saving My Memory For When I Develop Alzheimer's"


78 F-150 429CJ,Silver
w/Explorer Pkge.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon

 

Yes to both. The proportioning valve is the one off the 76 and I've adjusted the rear brakes to where the shoes are alomst touching the drums. I don't think the rear brakes are the problem since it drove fine before I swapped front ends. Any other ideas??? Thanks!

 

Are the front hoses new or recent? As these age they can restrict flow, although if they're doing so the brakes often are slow to release.
Eric