Brake master from a 96 F250?

[manimal]

I did some reading on FTE last night and someone mentioned using a master cylinder from a 96 powerstroke on our trucks? I need to replace the master cylinder as it goes straight to the floor. I just put calipers and front pads on today. After I was done bleeding brakes, the pedal with not hold pressure and if I pump it up, it bleeds off. So Im just curious if this is a viable upgrade or should I just get a new master for MY truck? Thanks
...BTW if I had not been stupid and sold my 2 hydroboost set ups, I would got that route FOR SURE..lol

 

[chillman88]

Although I have no facts on the matter I would "assume" they should be the same as far as master cylinder goes. I heard something about an upgraded vacuum booster but I don't know what year the change was.

 

[chillman88]

I am wrong!

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The 96 master has a slightly larger bore size, therefore it moves more fluid. I'm not sure what others will say but it's worth looking into.

I believe I did a similar upgrade to my Chevy although I did hydroboost at the same time so I couldn't tell you if it made a difference.

 

[snicklas]

Have you MANUALLY adjusted the rear brake shoes, and did you bleed the RABS valve is you had the rear lines open.... and in the correct order?

1. Right Rear
2. Left Rear
3. RABS
4. Right Front
5. Left Front

Basically farthest from the master to closest.....

Our 92 did he same thing after a brake line repair(s). Put your foot on the brake and the truck will stop, but sitting with your foot on the brake it slowly starts to sink..... Got out the spoon and adjusted both sides till just dragging, no more sinking...... We did have a bit, but nothing like before, I think even if you bleed them EXTREMELY well, you only get about 99.98% of the air out, and the little bit that is left does work itself out over the first couple of days.......

All that being said, the larger bore master cylinder will move more fluid and help to counteract the shoe adjustment / cylinders filling / pedal sinking some... but a good adjust will help more..... do both and you will have a bit better brakes. Remember the master cylinder used on the F-Superduty with Hydroboost uses a larger bore master along with the hydraulic booster......

 

[manimal]

I bled everything BUT RABS...Ill do that tomorrow. But I still believe I need a new MC. it does not hold AT ALL. So in order to bleed RABs, do I pump 3 times, hold and crack open bleeder just like each corner?

 

[icanfixall]

yes. Just have someone pump up the brakes. Then crack open the rabs. Repeat. BTW the bore on the hydroboost brake master cylinder is 1 5/16.Its a big boy and it sure works well.

 

[no mufflers]

When I bleed the brakes I hook up the vacuum bleeder and crack the bleeder screw then pump the pedal a few times. It seems to work the best for me.

I put a 97 booster and master on my 79 250 an I can lock all the tires up if I jack on the pedal.

 

[FORDF250HDXLT]

yes. Just have someone pump up the brakes. Then crack open the rabs. Repeat. BTW the bore on the hydroboost brake master cylinder is 1 5/16.Its a big boy and it sure works well.

I'm glad I followed your advice in past threads,for using this master on the hydroboost swap.It really helped big time to get some rear braking.

 

[manimal]

Well, I dont know what Im doing wrong. I bled the entire system 3 times. NO AIR came out. and I DEFINITELY would NOT want to have to do a panic stop...wouldnt happen. I do not have a RABS light on - on the dash, it comes on when key on, then goes out.

 

[no mufflers]

did you check the rear breaks? I had to bleed the **** out of my rear breaks until I got a decent pedal.

 

[manimal]

Yeah, Im gonna take the rears apart and make sure everything is in perfect working order. Wish I would have kept one of my hydroboost set ups

 

[Thewespaul]

I might have missed it but are your brake hoses new?

 

[manimal]

No they arent. I have been thinking about replacing them with braided lines.

 

[chillman88]

Yeah, Im gonna take the rears apart and make sure everything is in perfect working order. Wish I would have kept one of my hydroboost set ups

I hear you there. My booster is leaking and I'm hoping to sneak by until tax time and do hydroboost instead of replacing the vacuum booster. It was night and day difference in my Chevy, I'd assume the same in our Fords.

 

[Thewespaul]

No they arent. I have been thinking about replacing them with braided lines.

Priced out the braided and it was a pretty penny for my truck so I went with regular rubber I had a squishy pedal/sticking brakes issue that new hoses remedied