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67shovel wrote:I bumped up the master cylinder bore (1.25" I beleive) to the largest one that would still fit into my aftermarket small outside diameter power booster. The master cyl is from a 2002 F150 (e gads!). Also picked up and adjustable proportioning valve and replaced the factory saftey swith block. Pedal is firm now! Up on jack stands I can't hardly stop the rear wheels in gear! Pulled the rear center hose and have good flow to it. Now I'm pulling a caliper as I could hardy pump the piston out with it hanging in the air. Got to be swelled hoses or corroded calipers.
Update, just pulled one caliper, popped out piston. No corrosion, can blow thru brake hose, clean it with soap and water and reassembled using brake fuild. All back on car on jack stands, fire it up, put in gear and still can't stop the rear wheels from spinning while on stands It's got to be the master cylinder I guess. I didn't get a disc/disc MC as suggested and I guess that what I need to do next. I verified good fuild flow through the lines too
avewhtboy wrote:My experience with hard pedal has always been a bad booster.
I was having a conversation with a friend of mine last night about this, since I am in the middle of installing
a Blazer rear disc brake axle in my car, he mentioned that the difference between drum rear brake and
disc rear brake master cylinders is a check valve going to the rear wheels in a drum brake master. If you remove
that check valve you can turn your drum master into a disc master.
I suspect the F250 2002 had a disc rear axle? if not may want to check that out.
67shovel wrote:avewhtboy wrote:My experience with hard pedal has always been a bad booster.
I was having a conversation with a friend of mine last night about this, since I am in the middle of installing
a Blazer rear disc brake axle in my car, he mentioned that the difference between drum rear brake and
disc rear brake master cylinders is a check valve going to the rear wheels in a drum brake master. If you remove
that check valve you can turn your drum master into a disc master.
I suspect the F250 2002 had a disc rear axle? if not may want to check that out.
My Ford Master has a device (1" hex x 1.25" roughly) screwed in to the rear port and after searching they said it was a proportioning valve. I took it off to "gut" it and found that it was just a straight hole through it, no valve. Does that make it a disc/disc M/C then? I hope as this is getting $$
The booster could be bad I pulled the vacume line off it last week and it was holding it's own vacume? Is that right? Might be that I used gas line and tubing for it vacum line and the gas line collasped. I have since replaced it with the correct type hose. I think my next more is swapping out to my other "Identical" power booster. I sorta stuck with these small boosters as I don't think a full size one would fit.
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