Brakes and Exhaust

[budha808]

I have a couple upgrades I would like to get on with but need some help first:

I have read a lot about braking issues and the benefits of upgrading to a 95+ (Grand) Cherokee DD booster. Most of these tech articles talk about needing to have the rod, which goes through the firewall replaced with one that will work on an XJ. My question is does anyone know if there is a booster I can use which will swap directly into my 91' without modification and still give me the same 'petal pressure' increase.

I was going to order a cheap cat-back from Summit but the details read very strange, it says it is for 1993-2000 Cherokees. What the hell is this? As far as I know there were no design changes from 91-94 so what gives? Will this cat-back work on my 91 HO?

Here is the part #: WLK-17340

Vendor: Dynomax Performance Exhaust
Product Line: Dynomax Super Turbo Exhaust Systems
Material: Aluminized Steel
Finish: Aluminized

Jeep: 1993-2000 4.0L Cherokee, single rear exit, 2 1/4 in. diameter, Super Turbo exhaust system

:D

[Lucas]

the newer exhaust has a big SS tip on the end, it looks pretty nice. The pn for the older models is for a regular tube that has a flared tip, looks pretty crappy.

[rsalemi]

The 95 (probably 96 also) Cherokee DD booster is a direct bolt in - you need the angled spacer between the booster and firewall but no rod changes. If you keep the newer prop valve and the two lines to the 95 MC then all you need are 3/16" couplers and short pieces of line to connect the existing lines to the setup.
If you keep the existing prop valve you need metric adapters on the two lines you need to make for the MC - hard to locate in my part of the Country.

[rsalemi]

Dynomax makes a direct fit cat back for the early Jeep - one difference is the early cats have a 4 bolt flange which is changed in 93+ to a slip-on unit.

[Eagle]

Why use a Grand Cherokee booster? The late model XJs use a dual diaphram booster, why not use one intended for your vehicle? I believe you still need to replace the rod from the pedal, but that's very minor compared to replacing the booster/master cylinder assembly and making all the associated plumbing adapters required.

[budha808]

So I can use a 95-6 XJ booster and get the same effect? I was trying to avoid replacing the rod but I am guessing this is not possible. Oh well it still seems like a brake upgrade that most poeple recommend and I really want to improve my brakes.

I am still unclear on the exhaust, the model number which covers my year at Summit online is cheaper (89.95) but also says the exhaust exits out the side, something I am not interested in.

If I am going to replace the cat with a high-flow unit and have the exhaust welded anyway will the difference matter?

Thanks for all the input

[ChiXJeff]

I bolted up a 95 m/c and vacuum booster on my 94 a year ago. The only fabbing was a set of adapter lines down to the prop valve, the 94 is SAE and the 95 stuff is metric.

[AZ Jeff]

I converted my 92 to the DD booster from a 95 XJ last winter. I used the booster and M/C from a 95-96, and fabricated new lines from the master to the existing '92 proportioning valve. These lines are unique, in that they have the ISO type bubble flare on the end that goes into the M/C, and the traditional SAE type flare on the end that goes into the Prop. valve.

I made these lines by buying some generic pre-flared ISO type lines at the parts house, and cut and reflared the one end to SAE type end. The end result is a MAJOR improvement in braking.

[budha808]

Just what I was looking for, I am going to get a 95 bb/mc tonight. I have a 8.25 and I am planning on converting to Grand rear disks at the same time but I am a little nervous about pulling the axel shafts as I have never done this. Any advice on the Grand rear disks with the new bb/mc. Will I need a prop valve or any other additional parts?

[AZ Jeff]

If you intend to put rear discs on the XJ, you will need to use the prop valve out of the ZJ.