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  #1  
Old July 6th, 2003, 13:58
jimmy forbes jimmy forbes is offline
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my brakes suck

i have always had brake problems, and now that im running 33's they are even worse. any ideas on upgrades?
thanks
jimmy
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  #2  
Old July 6th, 2003, 15:45
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Bloose Bloose is offline
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Rear discs would be a help. I too have brake problems. It appears to be that there are no, or very little, rear braking. I had the same problem with my '89. So the problem seems to span the 9 year gap. I am thinking about replacing my proportioning valve. That is the ONLY item I didn't replace in my old system. I replaced everything else with new, and I still had the same problem. So, this time I'm thinking about starting with it. Then again I know, for me at least, rear discs would be the answer.

HTH,
B-loose
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  #3  
Old July 6th, 2003, 16:15
rixXJphx rixXJphx is offline
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Make sure the rear drum brakes are properly adjusted.
XJ self-adjusters aren't worth a $hnitz.

Buy SOFTEST available pads for the front. They won't last as many miles, but I've found they have greater stopping power in general service.
I've never had occasion to tow with them or travel, uhm, 'briskly' on mountain roads, so I don't know how they fare under tough fade conditions.
Still, they work better than stock for daily driving.
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  #4  
Old July 6th, 2003, 16:37
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bradlyw bradlyw is offline
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i just got done swapping in a 96 brake booster into my 87. the 95 and up xjs have a double diaphram booster where as ours only have a single. this made a world of difference. and while it wasnt easy, it was worth every minute spent on it.

Brad
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  #5  
Old July 6th, 2003, 16:49
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Carpenter Carpenter is offline
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Quote:
Originally posted by bradlyw
i just got done swapping in a 96 brake booster into my 87. the 95 and up xjs have a double diaphram booster where as ours only have a single. this made a world of difference. and while it wasnt easy, it was worth every minute spent on it.

Brad
Right on, in the last year I have replaced every part of my braking system. I tried rear disks first, then fooled with the proportioning valve, finally I upgraded my booster and master cylinder. Upgrading to the dual diaphram booster was the only brake modification that made any truely noticable and worth-while difference. Try that first then work from there, you'll spend less money in the long run and will see the most benefit right away. www.madxj.com has a very helpful writeup on the swap.
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  #6  
Old July 6th, 2003, 22:43
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dirtclod dirtclod is offline
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There was a thread on Pirate a while ago about putting a Ford 350 Van master cylinder on an XJ. They said it was nearly a direct install, aside from wallowing out a few bolt holes. They said the result was stopping power that would put you through the windsheild. I haven't done it, but I printed it out somewhere. I will have to look for it.

Pretty cheap too, as the master cylinder was only about $30 to $40, if I recall.

I'm not real confident on my understanding of the master cylinder/vacuum booster system. I get it that adding a bigger booster or double diaphram will increase stopping power. How are the master cylinders different between XJ's and heavy trucks that makes up the difference in power? Are the piston sizes different or just the lever arm of the brake pedal?

Anyone know?
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  #7  
Old July 6th, 2003, 22:56
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1986xj 1986xj is offline
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A bigger booster in reality can't make your brakes work better, just easier, right? If the pads, calipers, rotors, shoes, wheel cylinders, and drums are all still the same then they still supply the same stopping power as was available before, it's just with the bigger booster you don't need to push the brake pedal as hard. With the stock booster I'd think it would be able to achieve the same braking if you would just press harder on the pedal. Maybe I'm wrong? It's just that I've owned a few manual brake (no booster that is) vehicles over the years and always thought they stopped fine, I just had to really stand on the pedal to get them to lock up.
Mike B.
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  #8  
Old July 6th, 2003, 23:24
BLUTO BLUTO is offline
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Post brakes suck

I just bought new slotted front discs from raceconcepts.net
I dealt with a guy named "Wood", I think he is the proprietor. Anyway,...nice rotors, slotted $120 + shipping for the pair and for $40 more, I got HD (he tells me ceramic) brake pads. The slotting helps to release outgassing from the pads during hard usage,....these gasses act like water and "hydroplane" the pad over the rotor.
Wood doesn't suggest drilled rotors, because they can get small stones caught in there and they have a tendacy to crack at the hole. I haven't installed them yet, too damn busy!
I'll write them-up when I get them on.
BLUTO
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  #9  
Old July 7th, 2003, 00:22
rixXJphx rixXJphx is offline
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Quote:
Originally posted by 1986xj
...With the stock booster I'd think it would be able to achieve the same braking if you would just press harder on the pedal. Maybe I'm wrong? It's just that I've owned a few manual brake (no booster that is) vehicles over the years and always thought they stopped fine, I just had to really stand on the pedal to get them to lock up.
Older vehicles with drum fronts didn't NEED a booster, but it made it a lot easier for little old ladies to drive big honkin' Buicks.

Disc brakes NEED the boost, in order to achieve as much braking as a previously-drum-equipped version of the same vehicle.

Smaller vehicles (~2500 lbs) can run discs w/o boost, but as you say, ya gotta push hard.

On a heavier vehicle, pushing REALLY hard will distort the brake pedal arm, the mounting bracket, and the firewall mounting of the MC. Boosting occurs after both of these points, so greater boost really can deliver more effective braking.
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  #10  
Old July 7th, 2003, 05:30
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Bloose Bloose is offline
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I just converted my 1968 Fairlane Fastback to Disc brakes from drum. The drums were manual and the discs are too. That is NO booster with disc brakes on a 3500lb car. The drums worked fine with the exception of stopping at the end of the track. To much fade for me. Now I have manual discs and they work great! Why the hell does my 1968 whale with no power booster work great but my 1998 Jeep sucks!!!! Actually, the answer is that the rear brakes don't work at all, like I said. Adjusting them has little or no affect. I can put the Jeep on jack stands, put it in drive, and I can barely get the rear tires to stop no matter how hard I push the pedal. And I know the wheels cylinders are good. Like I said, this is the same darn problem I had in my '89.
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  #11  
Old July 7th, 2003, 07:16
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I'll give you my experiences so maybe you'll have something to go by. Here is everything I tried in the last year to improve my braking.

1. Rear disks with drilled rotors and high end pads, minimal improvement.

2. Modified proportioning valve to bias braking 50/50 front to rear, minimal improvement.

3. Braided SS lines all around, no difference.

4. Performance friction pads on the front, no difference.

5. E-350, one ton MC (as mentioned above), braking became much worse.

6. Upgraded to '95 dual-diaphram booster and MC. Huge improvement. The only modification I made that justified the costs, PERIOD.

The E-350 MC swap was a huge failure for me. I have read some reports of it working for others but it only made things worse for me. The dual diaphram booster mod was a night and day difference though.
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  #12  
Old July 7th, 2003, 07:47
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Safari Ary Safari Ary is offline
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Well, my brakes suck too, and I have an '01 which has the newer booster/MC. By suck I mean it's friggin HARD to push the pedal during normal day to day driving, let alone trying to achieve maximum braking. I can still lock up all 4 wheels on dry pavement, but my butt is no longer touching the seat because I'm pushing so hard at that point. My parents are truly terrified when they get in my Jeep and have to push so hard, and well, the ex-gf just flat out wouldn't drive it(ex for a reason?? ). Anyway, what is there to do to make it easier? Is this E350 booster swap the one for me? Thanks

Ary
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  #13  
Old July 7th, 2003, 08:05
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ChuckD ChuckD is offline
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Quote:
Originally posted by Ary'01XJ
Well, my brakes suck too, and I have an '01 which has the newer booster/MC. By suck I mean it's friggin HARD to push the pedal during normal day to day driving, let alone trying to achieve maximum braking. I can still lock up all 4 wheels on dry pavement, but my butt is no longer touching the seat because I'm pushing so hard at that point. My parents are truly terrified when they get in my Jeep and have to push so hard, and well, the ex-gf just flat out wouldn't drive it(ex for a reason?? ). Anyway, what is there to do to make it easier? Is this E350 booster swap the one for me? Thanks

Ary
Sounds like you need to do some work one your braking system.

My 93' 33" tires, stops really well. The only mod I have done, was swap in an 87' D35 10" drums. There smaller than the D44, but it stops a ton better than the 8.25" I had on there, even though the 8.25" pads are wider. Soon to have a D44 and maybe better braking to boot.
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  #14  
Old July 7th, 2003, 08:40
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Carpenter Carpenter is offline
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Quote:
Originally posted by Ary'01XJ
Well, my brakes suck too, and I have an '01 which has the newer booster/MC. By suck I mean it's friggin HARD to push the pedal during normal day to day driving, let alone trying to achieve maximum braking. I can still lock up all 4 wheels on dry pavement, but my butt is no longer touching the seat because I'm pushing so hard at that point. My parents are truly terrified when they get in my Jeep and have to push so hard, and well, the ex-gf just flat out wouldn't drive it(ex for a reason?? ). Anyway, what is there to do to make it easier? Is this E350 booster swap the one for me? Thanks

Ary
Sounds like you may have a bad booster. The E-350 MC will only make things worse for you, as it did me. The E-350 MC has a larger bore and stroke so it moves more fluid but at a lower pressure. Line pressure is what increases braking force. The E-350 swap should only be done if you have swapped in larger brakes that require a larger volume of fluid to operate properly, otherwise you're just wasting your time, as I did.
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  #15  
Old July 7th, 2003, 09:01
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Safari Ary Safari Ary is offline
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Well, I've had the Jeep since new, and it's always been like this. It gets slightly worse everytime I go up in tire size(to be expected one would think). I'm just looking to lessen the pedal pressure necessary to achieve effective braking. Thanks

Ary
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