F-150 master cylinder swap

[ThatGuy]

Whos' done it? What was the outcome? Is it straight bolt-on?

I'm just asking because I'm in the middle of doing it. Well starting at least. My master cylinder is off and am getting ready to re-install the F-150. The things I've noted so far......
F-150 master has the brake line ports on the opposite side from my Ex.
Piston measures .100 bigger than the Ex
Have to get an adapter or a completely new line for the front cuz it's a different size.

That's where I'm at, prolly won't work on it for a couple more days but I'll keep you up to date on what I come up with.

 

[Sasquatch_Ryda]

Which style are you using? The newer style with the plastic reservoir?

I've installed the old steel lid style one in my buddies 87 bronco II and it was a bolt in affair.

 

[ThatGuy]

Yeah the newer style with the plastic reservoir. It's for an early 90s model I think. It has the same low fluid plug at the bottom of the reservoir. Looks to be bolt on except for the lines being different.

 

[cammeddrz]

i used an f-350 master on mine (1 1/8" piston, stock was 7/8") i bent the lines to the other side and used $3 adaptors from checker to accomodate the larger fittings. the bolts that hold it to the bosster were about 1/8" further apart i just used my carbide on a die-grinder to make them fit. how did you deal with it?

 

[Viper Command]

i used an f-350 master on mine (1 1/8" piston, stock was 7/8") i bent the lines to the other side and used $3 adaptors from checker to accomodate the larger fittings. the bolts that hold it to the bosster were about 1/8" further apart i just used my carbide on a die-grinder to make them fit. how did you deal with it?

What year? 4wheel disc, rear drum?

is this do-able for a '97 w/ rabs and 8.8 rear disc????

 

[cammeddrz]

What year? 4wheel disc, rear drum?

is this do-able for a '97 w/ rabs and 8.8 rear disc????

for the most part the master just pushes fluid. your proportioning valve is what makes it work for drum/disc etc.

mine is a 1988 broncoII so mine is disc/drum

 

[Viper Command]

for the most part the master just pushes fluid. your proportioning valve is what makes it work for drum/disc etc.

mine is a 1988 broncoII so mine is disc/drum

Im sorry I was asking about the f-350 master you used.

 

[cammeddrz]

Im sorry I was asking about the f-350 master you used.

it was a metal-lid one i think i just got it for the same year so 1988.....its been a while i do know that it is a 1 1/8" piston

 

[Viper Command]

thank you very much.

 

[cammeddrz]

thank you very much.

i looked it back up, i got it for a 1985. the 1988 had a plastic reservoir

 

[ThatGuy]

Ok so today I have finish my brake master cylinder swap. I say finished but really I'm not. I'm pretty much in the same boat I was in before. Spongy pedal.

I mounted the master cylinder up. Went and got new lines and ran to the front and rear. Bench bled the master, bent and ran the lines, bled all the lines. Still got spongy pedal. It's different than before but still won't work.

I don't know what else to do. I've got new calipers and new rear wheel cylinders, no leaks. Can't get a decent pedal for nothing.

Any ideas?






Edit: I also bypassed the RABS valve long ago so I have straight lines to the front and rear.

 

[cammeddrz]

that happened to me just switch the lines around on the master i got it wrong somehow on my first try. and also is your proportioning valve the correct one for your brakes? like if you have drum rear and disc fron, is the valve for that same setup? there are different valves for different setups (e.g. drum/disc, disc/disc etc)

 

[ThatGuy]

I originally had no valve. I bypassed the RABS valve when I still had the TTB axles and it drove great like that. Ever since the axle swap I've had spongy pedal so I assumed that it was because I had too small a master on there. I swapped the F-150 master on and same thing. Today I added an adjustable prop. valve to the rear line and still nothing.

Any ideas??

 

[cammeddrz]

I originally had no valve. I bypassed the RABS valve when I still had the TTB axles and it drove great like that. Ever since the axle swap I've had spongy pedal so I assumed that it was because I had too small a master on there. I swapped the F-150 master on and same thing. Today I added an adjustable prop. valve to the rear line and still nothing.

Any ideas??

like i said: swap the lines around on the master, tha is what turned out to be my problem when i had the exact same symptom

 

[ThatGuy]

like i said: swap the lines around on the master, tha is what turned out to be my problem when i had the exact same symptom

Once again, cammeddrz is correct. If I had only listned to him in the first place.....


Early '90s F-150 plastic reservoir--bolt-on, no mods necessary
Need 2 adapters and move brake lines to other side.
Hook up is Front to Frontand Rear to Rear
I can lock up the 36s with no problem.

I took the adjustable prop. valve off so I'm just running straight lines to front disk/rear drum (for now). I will probably put it back on when I go to rear disks.