jmdirk
Well-Known Member
- Joined
- July 22, 2004
- Messages
- 238
- Reaction score
- 14
- City, State
- Ottawa, Canada
- Year, Model & Trim Level
- '93
After doing my SAS and trying to get the brakes setup, I just could seem to get a good feeling in the pedal. Between swapping my 1st Gen to a 2nd Gen rear axle with disc brakes and the larger 79 T-bird calipers on the front axle, I wanted to get some better performance out of the brakes since at the time, they felt worse than stock.
This led me to do a bunch of calculations about which master cylinder etc to use to get the most of of my new brakes.. All the background can be found here:http://www.explorerforum.com/forums/showthread.php?t=424023
All the research and calculations led me to the decision to swap in a booster and master cylinder from a 1993 F-250. The larger MC should give a much firmer pedal feel and the larger booster will make up for any pressur e loss as a result of the new booster. For me, I had already pulled out all the 4WABS from the truck, so there was none of that stuff to deal with.
Start off by pulling the stock master cylinder;
- Disconnect the brake fluid level switch from the passenger side of the master cylinder reservoir
- Remove the front and rear brake lines from the master cylinder. Make sure you leave the reservoir cap on - this will help minimize the amount of brake fluid that will leak out all over the place. You can also pull as much fluid out as possible with a syringe or vacuum pump
- remove the 2 bolts securing the master cylinder to the booster and the master cylinder should just pull off
You should have something that looks like this:
Ignore the the mess of wiring to left, you probably won't have that. My biggest concern on this whole thing was the space for the larger booster. The stock booster is 8.75" and and the F250 one is 10.75". It's an extra inch all the way around. You can see that there already isn't that much space between the booster and the wiper motor about it.
Next is to remove the booster itself:
- undo the spring hose clamp from the vacuum check valve and remove the hose.
- go into the cab under the drivers side dash. On the brake pedal you'll see where the booster push rod connects to the brake pedal. Remove the spring loaded pin to release the push rod and brake pedal switch from the brake pedal.
- There are 4 nuts on studs that are securing the booster to the firewall. Remove the nuts and you should then be able to pull the booster out
Booster gone
There's two, possibly three, clearance issues with this swap; 1) the wiper motor; 2) the steering shaft and; 3) for me at least, my aftermarket shock tower was in the way. For stock vehicles or others I'm not sure if this will be an issue. Also, the clearance to the guard on the steering shaft may be an issue for automatics since the shifter linkage cable secures to the guard. Automatics may have more of a clearance issue than manuals.
Next I removed the wiper motor to give myself a little more clearance to maneuver the booster into place:
- remove the access panel in the center of the firewall by removing the three hex head screws holding it in place.
- Here's what you'll have inside:
The wiper motor arm is coming out from the firewall on the right. On the shaft you have the arm going to the drivers side wiper (you can't really see it since it's going away from you). The piece you see on the peft is the linkage for the passenger side wiper.
- On the end of the shaft is a special spring circlip, which attaches like this (thank you autozone for the picture):
- Once you get that off you can pull the arms off the shaft
- Remove the 3 bolts securing the wiper motor bracket to the firewall and disconnect the wiring and you should be able to pull the wiper motor free
Comparing the two new boosters:
Once you have all that stuff out of the way you can put in the new booster. It will take some wiggling to get it in place, but it's not that bad. The bolt holes line up exactly.
Here's the new booster in position:
Very little clearance to the guard over the steering shaft
Once you've got that in place, put the nuts back on from inside and hook up the brake pedal to the push rod.
On the booster itself, the push rod for the master should extend between 0.980" and 0.995" from the face of the booster. Connect your vacuum line to the check valve
Back under the hood, putting on the new master is pretty straight forward, slide it over the studs, and use the 2 nuts to secure it.
I have finished hooking up the line yet. The ports on F250 MC are 9/6-18 for the front and M18 x 1.5 on the rear. The rear port is designed to take a factory style pressure limiting (proportioning valve). I still need to figure out and get the correct fittings. I'm using a adjustable proportioning valve so I don;t need the factory one.
Once I get the right fittings I'll get it all bled etc. and see if that was worth the effort
This led me to do a bunch of calculations about which master cylinder etc to use to get the most of of my new brakes.. All the background can be found here:http://www.explorerforum.com/forums/showthread.php?t=424023
All the research and calculations led me to the decision to swap in a booster and master cylinder from a 1993 F-250. The larger MC should give a much firmer pedal feel and the larger booster will make up for any pressur e loss as a result of the new booster. For me, I had already pulled out all the 4WABS from the truck, so there was none of that stuff to deal with.
Start off by pulling the stock master cylinder;
- Disconnect the brake fluid level switch from the passenger side of the master cylinder reservoir
- Remove the front and rear brake lines from the master cylinder. Make sure you leave the reservoir cap on - this will help minimize the amount of brake fluid that will leak out all over the place. You can also pull as much fluid out as possible with a syringe or vacuum pump
- remove the 2 bolts securing the master cylinder to the booster and the master cylinder should just pull off
You should have something that looks like this:
Ignore the the mess of wiring to left, you probably won't have that. My biggest concern on this whole thing was the space for the larger booster. The stock booster is 8.75" and and the F250 one is 10.75". It's an extra inch all the way around. You can see that there already isn't that much space between the booster and the wiper motor about it.
Next is to remove the booster itself:
- undo the spring hose clamp from the vacuum check valve and remove the hose.
- go into the cab under the drivers side dash. On the brake pedal you'll see where the booster push rod connects to the brake pedal. Remove the spring loaded pin to release the push rod and brake pedal switch from the brake pedal.
- There are 4 nuts on studs that are securing the booster to the firewall. Remove the nuts and you should then be able to pull the booster out
Booster gone
There's two, possibly three, clearance issues with this swap; 1) the wiper motor; 2) the steering shaft and; 3) for me at least, my aftermarket shock tower was in the way. For stock vehicles or others I'm not sure if this will be an issue. Also, the clearance to the guard on the steering shaft may be an issue for automatics since the shifter linkage cable secures to the guard. Automatics may have more of a clearance issue than manuals.
Next I removed the wiper motor to give myself a little more clearance to maneuver the booster into place:
- remove the access panel in the center of the firewall by removing the three hex head screws holding it in place.
- Here's what you'll have inside:
The wiper motor arm is coming out from the firewall on the right. On the shaft you have the arm going to the drivers side wiper (you can't really see it since it's going away from you). The piece you see on the peft is the linkage for the passenger side wiper.
- On the end of the shaft is a special spring circlip, which attaches like this (thank you autozone for the picture):
- Once you get that off you can pull the arms off the shaft
- Remove the 3 bolts securing the wiper motor bracket to the firewall and disconnect the wiring and you should be able to pull the wiper motor free
Comparing the two new boosters:
Once you have all that stuff out of the way you can put in the new booster. It will take some wiggling to get it in place, but it's not that bad. The bolt holes line up exactly.
Here's the new booster in position:
Very little clearance to the guard over the steering shaft
Once you've got that in place, put the nuts back on from inside and hook up the brake pedal to the push rod.
On the booster itself, the push rod for the master should extend between 0.980" and 0.995" from the face of the booster. Connect your vacuum line to the check valve
Back under the hood, putting on the new master is pretty straight forward, slide it over the studs, and use the 2 nuts to secure it.
I have finished hooking up the line yet. The ports on F250 MC are 9/6-18 for the front and M18 x 1.5 on the rear. The rear port is designed to take a factory style pressure limiting (proportioning valve). I still need to figure out and get the correct fittings. I'm using a adjustable proportioning valve so I don;t need the factory one.
Once I get the right fittings I'll get it all bled etc. and see if that was worth the effort
