Rear disc swap
06-30-2016, 08:45 AM
#16
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Location: Monett, MO.
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Year: 1999
Model: Cherokee
Engine: 4.0
I bought a complete kit with new parts also from Big David everything to do the job he supplied, and my ZJ swap does very well using the stock MC and prop valve guts he sent.
I may not know what I'm missing but this setup works very well over the old drum setup. Personally I see no need for myself to change them for another unit unless mine fails.
I may not know what I'm missing but this setup works very well over the old drum setup. Personally I see no need for myself to change them for another unit unless mine fails.
06-30-2016, 08:47 AM
#17
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Join Date: Aug 2011
Location: Prescott, Az
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
I bought a complete kit with new parts also from Big David everything to do the job he supplied, and my ZJ swap does very well using the stock MC and prop valve guts he sent.
I may not know what I'm missing but this setup works very well over the old drum setup. Personally I see no need for myself to change them for another unit unless mine fails.
I may not know what I'm missing but this setup works very well over the old drum setup. Personally I see no need for myself to change them for another unit unless mine fails.
06-30-2016, 08:58 AM
#18
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Location: Springfield, MO
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Year: 1996
Model: Cherokee
Engine: 4.0
One comment that I want to throw out to the OP is be prepared for things to go wrong. When i did the disc brake swap, I ran into issue after issue with the old brake lines being rusty and brittle and the connections not wanting to come apart even after liberally applying PB Blaster well before I started the project.
I ended up replacing all of the lines from the MC. I had a mechanic friend of mine recommend the Nickel/Copper brake lines and am glad that I went that way. They are much easier to work with, easy to flare, easy to route and easy to bend. Plus they look good (at least for a while).
Thankfully I have a DD, so didn't have to rush to get the job done. Just be prepared.
I ended up replacing all of the lines from the MC. I had a mechanic friend of mine recommend the Nickel/Copper brake lines and am glad that I went that way. They are much easier to work with, easy to flare, easy to route and easy to bend. Plus they look good (at least for a while).
Thankfully I have a DD, so didn't have to rush to get the job done. Just be prepared.
06-30-2016, 10:58 AM
#20
CF Veteran
I bought a complete kit with new parts also from Big David everything to do the job he supplied, and my ZJ swap does very well using the stock MC and prop valve guts he sent.
I may not know what I'm missing but this setup works very well over the old drum setup. Personally I see no need for myself to change them for another unit unless mine fails.
I may not know what I'm missing but this setup works very well over the old drum setup. Personally I see no need for myself to change them for another unit unless mine fails.
Just did a member search for Big David....no results.
06-30-2016, 04:02 PM
#22
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Actually, the WJ booster is in some ways easier than the 95 to 96 XJ.
I've done both.
XJ, you don't have to mess with the firewall. No big deal anyway.
But, you have to move the washer reservoir. And, once the original booster comes out, the bracket inside the cab moves and makes it a bear to install the new booster.
WJ you have to bend or cut the firewall lip, but don't move the washer bottle.
As an added bonus, the mounting studs of the WJ booster are a bit smaller and it's easier to get in.
Another bonus with the WJ is that it has FLEXIBLE lines from the master cylinder that make putting things together MUCH easier.
And, WJ boosters are newer and easier to find…..
06-30-2016, 04:03 PM
#23
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
06-30-2016, 08:38 PM
#25
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Location: Pasquotank, NC
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Year: 1990
Model: Cherokee
Engine: 4.0
So the WJ booster will provide good brakes with the disc brake rear? Same pressure as the 95-96 xj booster? I am planning to buy a new booster/master anyways, so finding a good one in a scrap yard isn't really a concern. As far as modifications, I have no problem cutting and welding whatever I need. I work in a fab shop and have a fairly decent setup in the garage. Which setup provides the best brakes? Is there any noticeable difference between the two (XJ vs WJ)?
Last edited by bad_idea; 06-30-2016 at 08:43 PM.
06-30-2016, 09:35 PM
#26
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
So the WJ booster will provide good brakes with the disc brake rear? Same pressure as the 95-96 xj booster? I am planning to buy a new booster/master anyways, so finding a good one in a scrap yard isn't really a concern. As far as modifications, I have no problem cutting and welding whatever I need. I work in a fab shop and have a fairly decent setup in the garage. Which setup provides the best brakes? Is there any noticeable difference between the two (XJ vs WJ)?
06-30-2016, 09:36 PM
#27
No, I don't lick fish.
WJ versus 95 to 96 XJ booster
Actually, the WJ booster is in some ways easier than the 95 to 96 XJ.
I've done both.
XJ, you don't have to mess with the firewall. No big deal anyway.
But, you have to move the washer reservoir. And, once the original booster comes out, the bracket inside the cab moves and makes it a bear to install the new booster.
WJ you have to bend or cut the firewall lip, but don't move the washer bottle.
As an added bonus, the mounting studs of the WJ booster are a bit smaller and it's easier to get in.
Another bonus with the WJ is that it has FLEXIBLE lines from the master cylinder that make putting things together MUCH easier.
And, WJ boosters are newer and easier to find…..
Actually, the WJ booster is in some ways easier than the 95 to 96 XJ.
I've done both.
XJ, you don't have to mess with the firewall. No big deal anyway.
But, you have to move the washer reservoir. And, once the original booster comes out, the bracket inside the cab moves and makes it a bear to install the new booster.
WJ you have to bend or cut the firewall lip, but don't move the washer bottle.
As an added bonus, the mounting studs of the WJ booster are a bit smaller and it's easier to get in.
Another bonus with the WJ is that it has FLEXIBLE lines from the master cylinder that make putting things together MUCH easier.
And, WJ boosters are newer and easier to find…..
So the WJ booster will provide good brakes with the disc brake rear? Same pressure as the 95-96 xj booster? I am planning to buy a new booster/master anyways, so finding a good one in a scrap yard isn't really a concern. As far as modifications, I have no problem cutting and welding whatever I need. I work in a fab shop and have a fairly decent setup in the garage. Which setup provides the best brakes? Is there any noticeable difference between the two (XJ vs WJ)?
Last edited by Basslicks; 07-01-2016 at 04:00 AM.
07-01-2016, 03:54 AM
#28
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Year: 1990
Model: Cherokee
Engine: 4.0
Last question. Probably. If the WJ came with rear discs, why yank the prop valve guts from the ZJ? Why not just grab booster, mc, and prop valve (whole prop valve) from the WJ and bolt that into the XJ? Why the ZJ prop valve guts over the WJ prop valve?
07-01-2016, 08:34 AM
#29
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
I'm not sure WJ has a prop valve with it's ABS. And if it did, nobody has used it/verified it.
07-01-2016, 09:12 AM
#30
CF Veteran
I recently did a rear disc swap. I used the kit from MRBLAINE over on Jeepforum as I figured it'd be nice to have all brand new stuff. blackmagicbrakes is his website. Went fairly smooth. Definitely be prepared to do brake lines(I was mentally but not physically but I also had a few days so ran to the store a couple times...lol). I have since locked up the brakes(for testing) and found with the original prop valve the front and rear lock up near the same. I'll find out this winter if I need to scavenge the prop valve from my parts ZJ. IIRC the proportioning valve used in other TJ's was the same for both models with rear drums and rear discs. Cruiser probably can say for sure. Stupid drum brakes...