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Discussion Starter #1
I'm starting this new thread in an attempt to clarify the technical description and use of the Dodge Durango/Dakota MC that many look to use in upgrading their brake systems.

Additionally, the consensus of the various threads concerning the choice of MC's when upgrading to LARGER calipers, is to also upgrade to a dual diaphragm (DD) booster.

The choices for MC's that will easily fit, without significant mods, and properly seal with the DD booster, seem to have evolved to either the 1999-2003 Dodge MC for the 1500/2500/3500 Ram pickups, or the 1999-2003 Durango or Dakota MC. The choice between these seem to depend on hood clearance issues, and cylinder size.

The Durango, being a little shorter overall, seems to solve the hood issue, but has a smaller bore.

No one questiones the bore size of the Ram pickup MC, which everyone agrees is 1.250 inches.
However, not everyone needs the volume of the Ram MC.
Seems the alternative is the Durango, which, depending on which supplier you go to, the bore size ranges any where between 15/16 and 1.125.
Also, one person stated the Durango MC would not fit into a WJ booster. Was this a fluke? Or is it really true?
So lets compile some accurate, real experience regarding cylinder size for the Durango MC, and fitment from actual experience.

Rockauto.com carries a number of replacement MCs, with only a couple advertising cylinder sizes. The ones trhat do state size say 1.0625 (1-1/16).
I've also found a NAPA unit that advertises 1.125--remaned, no reservoir: number TS 102967.
Another supplier, Centric, advertises two different sizes for NEW MC's with reservoirs.
They have three units available:
One is 15/16 ID, and the other two are 1.125.
CE 131.67025, (1.125"), has a strange looking reservoir, that is short and tall. The MC appears to have banjo-bolt attachments for ports, which may enhance installation.
The second 1.125" unit is CE 130.67025. It looks like the normal MC everyone has shown pictures of in their respective threads.
Note, these CE units are advertised to fit all Durango models, '99-'03, and Dodge Viper models '03-'06.

Anyone have comments regarding the company Centric? They seem to have cheaper prices than Raybestos, and offer a huge selection of brake systems, and components.

How about some actual experience here, regarding installs of the Durango MC?
 

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The choices for MC's that will easily fit, without significant mods, and properly seal with the DD booster, seem to have evolved to either the 1999-2003 Dodge MC for the 1500/2500/3500 Ram pickups, or the 1999-2003 Durango or Dakota MC.
So... you do not want to discuss other master cylinder's that fit easily without significant mods?
Billy
 

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Discussion Starter #3
Yes, I would, if--and only if--they were installed on a dual diaphragm (DD) style booster that will fit a Jeep Cherokee with a manual trans (for clutch master cylinder clearance).
So, yes, viable alternatives welcome.
 

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Yes, I would, if--and only if--they were installed on a dual diaphragm (DD) style booster that will fit a Jeep Cherokee with a manual trans (for clutch master cylinder clearance).
So, yes, viable alternatives welcome.
Well, I don't know about the manual trans issue, but I installed a Corvette master on my '95 (auto w/ dual diaphragm booster) and on a friend's '97 (auto w/ dual diaphragm booster). The only mod that was required was lengthening the push rod (or replacing it with a modified bolt). Here's the specs on the one we used. It seemed to work well w/ an adjustable prop valve to the rear.
67-76 Vette Master Cylinder
Napa#10-1423
RAYBESTOS Part # MC39018
1 1/8" bore

Billy
 

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Discussion Starter #5
Bump for more tech:p
 

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Discussion Starter #6
Jeepfreak, how did you seal the Vette MC against the DD booster? Supposedly, you must obtain a vacuum seal where the MC attaches, on a dual diaphragm booster.
 

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Good thread, I think I'll need the Ram MC.
Does the RAM MC bolt up to an '88 booster perfectly?
What needs done?
 

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Discussion Starter #8 (Edited)
The Dodge ram MC discussed in this thread is intended for a dual-diaphragm booster found stock on some '95 and on all '96 and latter XJ,ZJ, and WJ's--not the earlier single-diaphragm boosters like those found on the '88 XJ/YJ's.
A good volume-boost MC for the '88 booster is an MC from a Mercury Grand Marque that had the hydro-boost option. It bolts right up to the early booster without mods--just need to adjust the booster to MC push-rod (it's adjustable).
The Marque MC is 1.125 bore, so don't use it unless you've increased the size of your caliper pistons, and have converted to 4-wheel disc. Another option for the early XJ is the '85 vette MC used with power brakes. It does require a little massaging to install. It is also has a 1.125 bore, and is intended for 4-wheel discs. Personally, I wouldn't increase the volume (size) of your MC until you upgrade to a dual-diaphragm booster. Your pedal will be hard, and it will reduce your affective braking power.
 

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I have huge Ford dual piston calipers on my Front Dana 60, and single piston Chevy disc conversion in back on a 14 bolt.

My 88 MJ has the old single disphram booster, So... Tell me does this sound correct?
-Get a WJ booster (Are the WJ better than ZJ booster?)
- Get a 1999-2003 Dodge RAM 2500 MC
-Cheap Adjustable Prop Valve.

Sound good?
 

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Discussion Starter #10 (Edited)
Not sure if the ZJ booster is better, or the same as a WJ booster. But, based on web writ-ups, the WJ is a for certain bolt-in with minor mod application.
As far as selecting a MC to bolt on to the WJ booster, I'd prefer the 1.125 bore unit for your application. The '99-'03 Ram MC has a 1.250 bore, a little big, in my opinion.
Might try the Dodge Durango ('98-2004) MC. Insure you get the 1.125 bore version. I've seen them advertised as 15/16-1.125. Doesn't seem to be a correlation between "Vin" #'s and bore size.
O'Reilly advertises a new, 1.125 MC, with reservoir for $81. That may be worth looking at: part number 132967.
If you live near a large population area, you might be able to go to a parts store and check out the WJ booster, and Durango MC. Insure the MC will fit into the booster, so that it creates a vacuum seal.
 

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Discussion Starter #11
A little more fact, regarding the Durango MC.
Cardone, an after market mfg of auto parts confirmed that Cardone part number 132967 has a bore of 1.125.
This MC is listed by both Rockauto.com and Autozone for the 2003 Dodge Durango with 5.9L v8.
They also stated the "snout" has an OD of 1.9".
I've ordered a 2000 WJ booster, and should be able to determine if the Durango MC will fit properly, in the near future.
 

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Discussion Starter #13
I didn't want a junk-yard unit, so I picked rockauto.com for a "remanufactured" unit; best price I could find.
I've bought a number of parts from them. I've always been satisfied.
 

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Jeepfreak, how did you seal the Vette MC against the DD booster? Supposedly, you must obtain a vacuum seal where the MC attaches, on a dual diaphragm booster.
Sorry for the delay... been on a cruise ship for the last 5 days! :flipoff2:

We just used cut-to-fit cork (or paper maybe?) gasket material. Press the master cylinder onto the gasket material to make an outline and then cut it out.

Billy
 

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Discussion Starter #15
Thanks for the reply, Billy. I've ordered a 2000 Durango MC, even though one poster has stated it would not fit the WJ booster. Evidently he didn't actually try to mate the two, just measured the MC. I'm was skeptical of his measurements.
The ID of the hole in the WJ booster is 1.735--obviously, if the whole "snout" of the Durango MC is 1.9, as previously posted, it won't fit. But I have reason to believe the 1.9 is a very short portion of the "snout", where it seals against the booster. We'll see!
 

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Discussion Starter #16
Also, the WJ booster's MC push-rod does not appear adjustable. Anyone have experience with this?
And should it be possible to compress the booster using the pedal end?
 

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Discussion Starter #18
OK, well my '03 Durango MC arrived today.

My measurements confirm what others have indicated--it won't fit a WJ booster, without grinding the booster hole for the MC out to 1.90+, and elongating the Durango MC's bolt holes.
The MC's "snout" measures 1.90 at the MC, then tapers quickly to 1.735. The WJ booster's hole measures 1.735, and the MC mount studs are 3.578 on center--much wider than the Durango's mount holes at 3.209.
I'm returning the WJ booster, and have ordered an '01 XJ booster to install in my '88.
 
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