98 TJ, 3" Rusty's lift, 32" MT/Rs on steel wheels

When I step on the brake pedal to come to a hard/fast stop, the Jeep veers to the left. I have to turn the wheel about 45* to the right to keep it straight.

What I've done so far:
new rotors
new pads
replaced both calipers with rebuilt units
vacuum bled the system 3 times
tire pressure is okay
nothing bent or loose in the steering system

What am I missing? Could it be brake hoses? Proportioning valve? Master cylinder? Evil gremlins grabbing my left front wheel?

Is there a way to test the fluid pressure at each wheel?

Thanks for any good thoughts or advice.

I would guess the r/ f caliper ain't working. I've gotten rebuilt calipers before that were no good.

Alignment?

What about bump steer? Have you replaced either the tie rods or the front track bar.

I have Rusty's inverted T steering and I get SEVERE bumpsteer under hard braking ... and acceleration.

cm "don't get me going on Rusty's" k

Are you still using the stock pitman arm?
Any bumpsteer?
Is your draglink (short tie rod) level?

Could be that front end dive during braking is pushing the on the knuckle as the distance between the two lessens. This would only affect a rig with a pretty radical draglink angle and any such rig would also have an almost intolerable amount of bumpsteer.

If none of that applies to your Heep, I dunno... Sounds like you already did all the obvious stuff. maybe you should consider taking it to Midas and let them test the pressure...


HTH,

Jake Harsha

Originally posted by cmk
Alignment?

What about bump steer? Have you replaced either the tie rods or the front track bar.

I have Rusty's inverted T steering and I get SEVERE bumpsteer under hard braking ... and acceleration.

cm "don't get me going on Rusty's" k

Oh man, CMK beat me to the punch!

Ouch.

:D:D:flipoff2::D:D Jake

I guess I should have included a few more details. The lift has been on for 1.5 years with no prior problems.

The Jeep has 56500 miles showing, so that means about (correcting for tire size - 56500*1.09) 61585 actual miles.

I haven't replaced any front end components - ever. Everything still feels nice and tight when I check.

I'm thinking that I may swap the caliper out again. I love the Autozone lifetime guarantee.

So Midas can check brakeline pressure, eh? I kinda hate to have them fool with it but if it's a last resort... :D

With only 3" of lift and the stock steering/track bar, there shouldn't be a "severe" amount of bumpsteer.

I would look to the brakes again.

Also, check your alignment as well (toe). You can measure that yourself with a tape measure with reasonable accuracy. Just measure across two points on the front and the back of the front tires (9 o'clock and 3 o'clock respectively). You shouldn't have more than a 1/8" deviation. Factory spec is no toe at all ... both tires perfectly parallel.

cm "Indiana, back woods alignment method" k

Originally posted by CoryB
I'm thinking that I may swap the caliper out again. I love the Autozone lifetime guarantee.

So Midas can check brakeline pressure, eh? I kinda hate to have them fool with it but if it's a last resort... :D

Any decent brake shop should be able to check it. I'd replace the caliper one more time first though, just in case...

I once replaced my alternator with two bad re-man alternators in a row. (Talk about frustration... :confused: )

Good luck,
Jake

ive heard the lines can get soft and pinch or cause drag, ive been told it a few times, but ive never seen it first hand, but it seems youve gotten every other variable out of the equation.

I had the same problem and it was due to my toe being out, quick trip to the alignment shop took care of it. :beer:

My XJ does taht too, but I have 7" of lift with stock steering, so that expains it. Damn lack of funds, or spending too much money on :beer:

How about a pinched brake line?????

A couple of things that you might look at.
I would expect the left caliper to react faster than the right side if you stomp on the brakes, due to the longer brake line to the right side.
Does it still turn left with a longer hard stop?

Most of the rod ends I have seen are sping loaded to keep them tight as they wear. You may not feel any thing until they are really shot. Try pushing the tapered stud into the body with a pair of channel locks.
Could be something is worn enough to get you out of alignment under the stess of a hard stop.

HTH
:usa:

Originally posted by Keyster
A couple of things that you might look at.
I would expect the left caliper to react faster than the right side if you stomp on the brakes, due to the longer brake line to the right side.
...

One of the really nice features of hydraulics, there is no lag time in response due to length of the lines. Fluid does not compress.

True fluid does not compress.
But, a restriction or a long line will effect the speed of the fluid traveling to the caliper.
A restiction will not effect the pressure if there is no flow.

:usa:

Originally posted by Keyster
True fluid does not compress.
But, a restriction or a long line will effect the speed of the fluid traveling to the caliper.
A restiction will not effect the pressure if there is no flow.

:usa:

A restriction will affect both flow & pressure. A long line will not as the line is full of fluid.
That's why Cat put the pressure relief valves a long way from the actual impliment it is controoling. It makes no difference where the valve is as long as it is in the system.

Originally posted by JeepinIan


A restriction will affect both flow & pressure. A long line will not as the line is full of fluid.
That's why Cat put the pressure relief valves a long way from the actual impliment it is controoling. It makes no difference where the valve is as long as it is in the system.

Yeah dude. The pressure is going to be equal no matter what the discrepency in line lengths. One could be 30 feet long and it wouldn't make a $hit's worth of difference because they're both being compressed (well, moved anyway) by the same master cylinder and therefore part of the same container. (i.e. the lines)

Jake

My rig did this, and so did a pickup my father recently bought. Thing would go for the centerline every time you stomped the brake. Replaced the brake lines up front, problem solved. Actually, we only replaced the line on the passenger side. Passenger side line is kinked or plugged, you stomp the brakes, all the power goes to the driverr's side wheel instead of the passenger, yanks you into the other lane.

We tried bleeding the brakes several times, for some reason they always bleed fine. But when you stomp on the brake, they have some kind of blockage in them. I dunno.

I think it's almost definetly your brake lines. Since you do have the autozone forever and a day guarantee on the calipers, try that again, but I think you're gonna end up replacing the lines. Metal hard line is cheap and easy to bend, and the replacement rubber lines won't be too terribly expensive, I don't think. Might be a good time to treat yourself to the nice long stainless ones. That's what I did. :)

Good luck with it.

Boots

Sorry Keyster:rolleyes:
I gota agree with Jeepinian & Jakster.:D
They got it correct

Did you buy the calipers from track auto cause that could be your problem. I got 2 bad master cylinders in a row from them.

Does that '98 Have aitilock brakes?...I don't know if the newer Jeeps have them or not but the left sensor could be out-O-wack, and grabbing harder than the right.....Just a thought.

Mine did it too untill last tuesday.

I just replaced the rear brakes and had the drums cut.

No more pull...... :D

I'm wondering whatever happened with your pull to the left as you stopped? The only other thing I was going to say to check is make sure all the control arm bolts are tight as well as the steering componets. After a trip off-road, my Jeep was pulling to the left and it turns out I had a lose lower control arm on the drivers side. Also make sure you're tire pressures are the same as well. Different tire pressures can make a difference in braking.

btw, cmk, backwoods Indiana alignments work! My Jeep hasn't ever seen an alignment shop......DIY works!

mac 'if its a simple solution, i'll miss it' gyvr

Allot of good info, here is just a few more to look for. First do you have an oil leak that could put oil on the rotor? that can increase brakeing friction do to heat. Also the flexiable brake hose on the right side may have a bulge in it that is allowing pressure to expan it instead of press the brake caliper check it out.