'93 Ford E350 - Master cylinder bore size?
Haven't posted here for a while, and I'm not sure anyone can help or not. I will check with some of the more mechanic oriented pages as well, but I think this is somewhat specific to my vehicle being...
Forum Discussion
You're right, Ryan, haven't seen you here in literally years. We spoke on the phone. About a miss I think. Bear in mind that 1993 Class C chassis was only E350. The E450 and predecessor called E-Super Duty didn't come out for another half dozen years.
The physics gurus might correct me, but I believe that MORE diameter in a brake cylinder piston will result in LESS output pressure, not More, given that the linkage and booster provide the same pressure to that piston.
...Is a pic of what RockAuto.com shows as the OEM Motorcraft replacement for your master cylinder. E350 from 1990-1996. I look at Rock because they list a wide variety of parts for an application. That's "1-1/8" cast into the side of the cylinder in the picture. Other sources I looked at showed same size in the few cases where Diameter was included in the detail. Rock shows BRMC38 as its Motorcraft replacement part number and F4TZ2140BD as an alternate number.
I don't think Diameter is the issue. If not, what DO I think? What comes to mind:
1. Nature of Beast. Our 2002 E-FOUR-50 (that uses a hydroboost brake, not Vacuum like 1993 E350) has a crummy-feeling brake pedal that stops simply great when driven.
2. Contaminated Brake Fluid. A thorough (perhaps professional) flush, fill, and bleeding might yield some results.
3. Ryan's Beast has rear DRUM brakes. Are they working properly and adjusted up to the drum surface like they oughta be? The way we drive a motor home doesn't lead to enough stop-and-go, backward-forward, maneuvers to let the self-adjusters do their job.
4. The Brake HOSES may have deteriorated to the point where they expand a little under application pressure. If you don't have record of them being replaced, new ones might tighten that pedal feel up. There's a Hose to each front brake and one to the Rear axle. Your question makes me think about something I've noticed. Sometimes when the brake's applied, the hose will "jump" a little. I wonder if that "jump" means the hose is changing size (getting longer) with pressure. Any distortion in the hose is going to show up as softness in the pedal. I've seen this "jump" happen but didn't wonder till now if it ties to softness or loss of pedal.
5. Take the Diameter question to the parts counter at a large FORD dealership. A NAPA store as an alternative. Try to pick a time they're not busy and can spend time with you.
Good to hear from you, Ryan. Hope you've been well, call if I can help. Have a Blessed Christmas!
The physics gurus might correct me, but I believe that MORE diameter in a brake cylinder piston will result in LESS output pressure, not More, given that the linkage and booster provide the same pressure to that piston.
...Is a pic of what RockAuto.com shows as the OEM Motorcraft replacement for your master cylinder. E350 from 1990-1996. I look at Rock because they list a wide variety of parts for an application. That's "1-1/8" cast into the side of the cylinder in the picture. Other sources I looked at showed same size in the few cases where Diameter was included in the detail. Rock shows BRMC38 as its Motorcraft replacement part number and F4TZ2140BD as an alternate number. I don't think Diameter is the issue. If not, what DO I think? What comes to mind:
1. Nature of Beast. Our 2002 E-FOUR-50 (that uses a hydroboost brake, not Vacuum like 1993 E350) has a crummy-feeling brake pedal that stops simply great when driven.
2. Contaminated Brake Fluid. A thorough (perhaps professional) flush, fill, and bleeding might yield some results.
3. Ryan's Beast has rear DRUM brakes. Are they working properly and adjusted up to the drum surface like they oughta be? The way we drive a motor home doesn't lead to enough stop-and-go, backward-forward, maneuvers to let the self-adjusters do their job.
4. The Brake HOSES may have deteriorated to the point where they expand a little under application pressure. If you don't have record of them being replaced, new ones might tighten that pedal feel up. There's a Hose to each front brake and one to the Rear axle. Your question makes me think about something I've noticed. Sometimes when the brake's applied, the hose will "jump" a little. I wonder if that "jump" means the hose is changing size (getting longer) with pressure. Any distortion in the hose is going to show up as softness in the pedal. I've seen this "jump" happen but didn't wonder till now if it ties to softness or loss of pedal.
5. Take the Diameter question to the parts counter at a large FORD dealership. A NAPA store as an alternative. Try to pick a time they're not busy and can spend time with you.
Good to hear from you, Ryan. Hope you've been well, call if I can help. Have a Blessed Christmas!
