E350 Master Cylinder Questions

First a bit of history on my brake set up on my '99. Currently running 33's. Swapped in '96 ZJ rear disc brakes (onto my 8.25) a year or so ago and was somewhat disappointed as there was no improvement over the drums. Swapped in the ZJ proportioning valve and still no improvement. I ended up replacing the master cyclinder and brake booster (with stock parts) and that made a big difference. I also got a good brake bleeder set up. Added all new rotors and pads and got the set up to a level that I felt was acceptable.

Even though things are acceptable, I still feel like they could be better. I can not lock up my 33's. After recently adding more weight with an exo, I am looking for options to better the brakes a bit more. Before I really step up to a WJ swap or a Vanco big brake, I was wondering if I should try replacing my master cyclinder with an E350.

My buddy just did this on his '89 (with a similar set up) and it was an improvement for him.

So my real questions is: Other than the basic fitment issues (making holes bigger, trimming edges of mounting flange and the line fittings) is there any reason why the '86 Ford E-350 master cylinder won't work on my '99? I didn't know if this swap was specific to the earlier years.

So tying into that, is it even worth it? Will the bigger MC have any positive additions to my brake set up? I kind of thought for $40 it might be worth a shot.

Thanks for the help/advice.

Anyone?

First, make DAMN SURE that the rear calipers are not on the wrong wheel! If this happened, your bleeder screws will be pointing DOWNWARD instead of upward. All the air cannot excape when bleeding and the pedal will never get better. Believe me, I have seen this done before!! uhm . . . . I actually did it once

Second, I have done the E350 M/C install on an '89 XJ and my brakes were more spongy after. I went back to stock M/C.

One more thing . . . make sure the ZJ disks are all aligned properly. If you have new pads installed, the rotor should be centered between the pads so that you have very little travel of the caliper assembly when brakes are applied. The rotor should be sitting center of caliper bracket when pads and caliper are removed.

It is NOT a direct bolt-up for the newer 95ish+ dual diaphragm boosters, and it's actually not even close.

The Dodge 2500 MC is a much better fit. But your brakes will suck even more with that, you'll have a very hard pedal and less braking power. It's kind of counter-intuitive, but the larger MC will have a larger bore, which gives you less mechanical advantage over the calipers.

If you're keeping the D30 your options are limited, and the MC isn't one of those options.

vetteboy said:

It is NOT a direct bolt-up for the newer 95ish+ dual diaphragm boosters, and it's actually not even close.

The Dodge 2500 MC is a much better fit. But your brakes will suck even more with that, you'll have a very hard pedal and less braking power. It's kind of counter-intuitive, but the larger MC will have a larger bore, which gives you less mechanical advantage over the calipers.

If you're keeping the D30 your options are limited, and the MC isn't one of those options.

Click to expand...

That's what I was wondering and needed to know. Thanks. Like I said, things work, but I just wonder if they could be better.

Tally, I had to go through the antics of making sure they were on the right side when I did the install a while ago. We're good there. Thanks though.

vetteboy said:

It is NOT a direct bolt-up for the newer 95ish+ dual diaphragm boosters, and it's actually not even close.

The Dodge 2500 MC is a much better fit

Click to expand...

X2. I am runniong A 2500 on my Yj with full widths, and the change is night and day, like locking 40's on a dime. I think the 2500 may be a better approach, was pretty straight forward and just did some grindinga nd extended the push rod slightly.

compare pic here (stock TJ on bottom for comparison)


booster riod pic:



minor grinding:




in:



more info here, shoudl be pretty close on a TJ, XJ, YJ, etc

http://www.pirate4x4.com/forum/showthread.php?t=334736&page=9

geberhard said:

X2. I am runniong A 2500 on my Yj with full widths, and the change is night and day, like locking 40's on a dime. I think the 2500 may be a better approach, was pretty straight forward and just did some grindinga nd extended the push rod slightly.

compare pic here (stock TJ on bottom for comparison)

booster riod pic:

minor grinding:

in:

more info here, shoudl be pretty close on a TJ, XJ, YJ, etc

http://www.pirate4x4.com/forum/showthread.php?t=334736&page=9

Click to expand...

Gui, what year 2500 MC did you use? And who did you order it through when you got yours. You said something about $70 to your door.

I currently have the E350 MC swap and it sucks. Pedal to the floor and it still won't lock them up. Funny thing is I can get a great pedal with the jeep off when I'm bleeding the brakes but as soon as I fire it up and the booster kicks on the pedal goes back to the floor. Oh and its on a 98' XJ with the stock booster and modified to fit E350MC and stock proporting valve. I've bled the **** out them thinking there is still air in the lines but if that was the case then I don't think I'd get a great pedal with the engine off.
Could there be a leak in the seal between the booster and MC? Would that cause it? It will stop on the road eventually but when in 4L its all I can do to get it to slow down and unless I keep the pedal to the floor hard it won't hold it. I think I'm going to check the pushrod adjustment too.

i cant speak for Gui, but i bought used parts through www.car-parts.com and have things shipped to my front door for cheap.

I bought it via partsamerica (kragen.com), total was about $70 shipped. If believe it is a 99 and up Dodge Ram 2500 MC, I think was the same part number for the 3500 MC. I think www.rockauto.com may have a better deal.

geberhard said:

X2. I am runniong A 2500 on my Yj with full widths, and the change is night and day, like locking 40's on a dime. I think the 2500 may be a better approach, was pretty straight forward and just did some grindinga nd extended the push rod slightly.

compare pic here (stock TJ on bottom for comparison)

booster riod pic:

minor grinding:

in:

more info here, shoudl be pretty close on a TJ, XJ, YJ, etc

http://www.pirate4x4.com/forum/showthread.php?t=334736&page=9

Click to expand...

That's what I'm talking about. Pics and everything! Thanks!

What is that you used to extend the pushrod? Kind of looks like aground down allen bolt.

Good eye! Bolt grounded round on the tip to fit smooth on the MC. I ended up using a grade 8 bolt inthe end just in case. The stock one could have worked, but I would need to unthread it some, and did not want to risk it failing.

Hey Gui - nice to see you over here.

I just revisited my 2500 MC project last night (never got around to doing it, and the rig is down right now so I figured I'd play with it). Mine looks nothing like yours...I think I got one for a '94. I'll post up some pics in a little bit.

The area where yours seals to the booster looks like a better fit than mine. I might have to investigate that more.

geberhard said:

X2. I am runniong A 2500 on my Yj with full widths, and the change is night and day

Click to expand...

which brakes do you have on the full widths?

Cool, if yuo have info on your MC let me know. I just got an XJ, but the brakes really do suck, so was thinking going with a TJ booster (sine I have the part) and doing the MC upgrade. Basically the pedal is pretty lousy

Shorty, on the YJ, Ford Dana 60 front dual piston calipers, on the rear, Chevy 14 bolt with Chevy front 3/4 rotors and single piston caliper.

very good chance that the 2500 MC works for the larger calipers better than the YJ MC as you need alot more volume moved, but (IIRC) the YJ/XJ brakes need a higher fluid pressure than you'll be able to provide without altering the pivot point on the pedal to increase leverage.

I did some comparisons a while back, wish I had kept my notes. I compared the bore sizes, and ballparked volume displaced. I think the E350 and Dodge were about the same if I recall. I am runnning a proprotioning valve to the rear brakes, so a bit better fluid control. Without it, I was locking up the rears pretty fast.



One other thing I almost forgot to mention is to remove the front pin from the stock proportioning valve. In my case, I removed the pin, and welded the center of the cap as it has a bleeding hole. Basically you can just bypass the stock if you are running a rear adjustable valve. You can see teh stock with teh cap welded abnd grind down under the picture showing the Dodge MC.

So quick question, teh XJ i got has the stock 30 brakes front, but the rear is a currie 44, so am assuming a ZJ disc brake, is that correct? I have not had a chance to check on it. Could be teh reason teh brakes suck right now....

I ran a booster, MC, and prop valve from a '95 ZJ w/disc brakes. Worked pretty well.

Here's the ZJ master cylinder compared to the Dodge 2500 one. The pushrod distance seems to be within 1/8" on them, and I briefly checked the pedal free play and it felt OK, so I'll see what happens when I get fluid in it and bleed it through. Like I mentioned though, yours has a different sealing surface to the booster than this one does, and this one uses larger fittings than stock, so I'm going to check out the newer ones as well and see what the differences are.

I just confirmed that the '99 Dodge 2500 MC has the same size fittings as my '95 ZJ MC. I might pick one up then instead of trying to get the '94 to work, especially if the seal is closer as well...

Tech info: ZJ and '99 Dodge fitting size is M10-1.0 and M12-1.0. '94 Dodge is 1/2" and 9/16".

vetteboy said:

I just confirmed that the '99 Dodge 2500 MC has the same size fittings as my '95 ZJ MC. I might pick one up then instead of trying to get the '94 to work, especially if the seal is closer as well...

Click to expand...

Do you by any chance know how those compare to a 97+ XJ MC?