How did you manage to mess up their rear brakes so they would lock up?

You need to address theirs before you worry about yours that work
right....

There 'IS' a reason that proportioning valve is in there!

Crap, in an emergency braking situation, locking the rears means instant
360's with total loss of control unless you really know what you are
doing.

Been there, done that a 'LOT' of times on purpose using the E-brake when
I used to ice race a front wheel drive Mini.

I could drive straight down a snow/ice road and just for kicks or show
in a competition hit the E-brake and do 2, 360's, let off the E-brake
and continue on in the exact same track I started from.

Mike

dave AKA vwdoc1 wrote:
>
> Hey I tried it with my 88 XJ with it down on the icy ground and with the
> brake pedal fully depressed the rear wheels would still spin. It would do
> the same jacked up in the air also = keep spinning. This was with a
> remanned master, new rear wheel cylinders, shoes & pads with all hydraulics
> bled well!
>
> My parent's 88 XJ will now lock up the rears. I had to do their rear brakes
> so they would lock up. The rear wheel cylinders were "locked"/rusted up and
> the wheels would keep spinning either in the air or on the emissions dyno.
>
> I would want to check my 88 XJ's proportioning valve. Waiting to get my
> 'round-2-it'! lol
>
> later,
> dave AKA vwdoc1
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:40E203A2.3FDF873E@sympatico.ca...
> > Yes, what the previous poster said about jacking up the rear end and
> > putting it in gear then trying to stop the tires in the air with the
> > brakes. It don't work for ----.
> >
> > Mike

 

How did you manage to mess up their rear brakes so they would lock up?

You need to address theirs before you worry about yours that work
right....

There 'IS' a reason that proportioning valve is in there!

Crap, in an emergency braking situation, locking the rears means instant
360's with total loss of control unless you really know what you are
doing.

Been there, done that a 'LOT' of times on purpose using the E-brake when
I used to ice race a front wheel drive Mini.

I could drive straight down a snow/ice road and just for kicks or show
in a competition hit the E-brake and do 2, 360's, let off the E-brake
and continue on in the exact same track I started from.

Mike

dave AKA vwdoc1 wrote:
>
> Hey I tried it with my 88 XJ with it down on the icy ground and with the
> brake pedal fully depressed the rear wheels would still spin. It would do
> the same jacked up in the air also = keep spinning. This was with a
> remanned master, new rear wheel cylinders, shoes & pads with all hydraulics
> bled well!
>
> My parent's 88 XJ will now lock up the rears. I had to do their rear brakes
> so they would lock up. The rear wheel cylinders were "locked"/rusted up and
> the wheels would keep spinning either in the air or on the emissions dyno.
>
> I would want to check my 88 XJ's proportioning valve. Waiting to get my
> 'round-2-it'! lol
>
> later,
> dave AKA vwdoc1
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:40E203A2.3FDF873E@sympatico.ca...
> > Yes, what the previous poster said about jacking up the rear end and
> > putting it in gear then trying to stop the tires in the air with the
> > brakes. It don't work for ----.
> >
> > Mike

 

How did you manage to mess up their rear brakes so they would lock up?

You need to address theirs before you worry about yours that work
right....

There 'IS' a reason that proportioning valve is in there!

Crap, in an emergency braking situation, locking the rears means instant
360's with total loss of control unless you really know what you are
doing.

Been there, done that a 'LOT' of times on purpose using the E-brake when
I used to ice race a front wheel drive Mini.

I could drive straight down a snow/ice road and just for kicks or show
in a competition hit the E-brake and do 2, 360's, let off the E-brake
and continue on in the exact same track I started from.

Mike

dave AKA vwdoc1 wrote:
>
> Hey I tried it with my 88 XJ with it down on the icy ground and with the
> brake pedal fully depressed the rear wheels would still spin. It would do
> the same jacked up in the air also = keep spinning. This was with a
> remanned master, new rear wheel cylinders, shoes & pads with all hydraulics
> bled well!
>
> My parent's 88 XJ will now lock up the rears. I had to do their rear brakes
> so they would lock up. The rear wheel cylinders were "locked"/rusted up and
> the wheels would keep spinning either in the air or on the emissions dyno.
>
> I would want to check my 88 XJ's proportioning valve. Waiting to get my
> 'round-2-it'! lol
>
> later,
> dave AKA vwdoc1
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:40E203A2.3FDF873E@sympatico.ca...
> > Yes, what the previous poster said about jacking up the rear end and
> > putting it in gear then trying to stop the tires in the air with the
> > brakes. It don't work for ----.
> >
> > Mike

 

Are you referring to the little "star" adjustment thingy or whatever?
How do I adjust this? I seem to remember seeing the guy at the brake
shop stick a screwdriver through the backing plate somewhere, but I
don't want to just randomly stick a screwdriver through one of the
backing plate holes without knowing what I'm aiming for ;-)

Thanks


"CRWLR" <beerman@yahoo.com> wrote in message news:<10e40r55hdoc08f@corp.supernews.com>...
> It sounds like you just need to adjust the brakes.
>
>
>
>
>
> "Bob" <magicclaw@mac.com> wrote in message
> news:47b769ae.0406290542.39c0c1a4@posting.google.c om...
> > I'm pretty sure it's not just that.
> >
> > I've been getting a seat-of-the-pants feeling that my braking power
> > has diminished of late; on the highway when traffic has stopped
> > suddenly, I've found myself having to smash down on the brakes harder
> > than before to get the jeep to stop in the same amount of time. While
> > I can still lock the front up, it just doesn't seem to be as
> > effective.
> >
> > This last weekend on the trail was my final straw: I was on a slight
> > incline, and tried to go up a couple of rocks (I was in 2wd), and spun
> > tires. So, I put the clutch in and hit the brake simultaneously, in
> > order to put it in 4-low to get through the little bit of rocks. As
> > soon as the clutch was in, the vehicle proceeded to roll back about
> > 10+ feet, with me standing on the brake pedal (in retrospect, perhaps
> > I should have pumped it). Either way, it was a bit freaky. The others
> > in my group said my front wheels were locked up, but my rears were
> > rolling, as I just rolled backward. It was like my rear brakes were
> > doing nothing, and just the locking-up and subsequent dragging of my
> > front wheels was all that stopped me.
> >
> > The braking improved a bit as the day progressed, but I decided maybe
> > I'd better check and see if the brakes were (a) in good shape still
> > and (b) not out of adjustment.
> >
> >
> > Mike Romain <romainm@sympatico.ca> wrote in message
> news:<40E08500.A9E6738F@sympatico.ca>...
> > > Are you sure you aren't just seeing the effects of a properly working
> > > combination valve?
> > >
> > > It acts like an anti lock brake for the rear wheels so they don't lock
> > > up easy if at all. Normally you don't want the rears locking, you can
> > > do 360's faster than you can blink if the rears lock up at speed.
> > >
> > > The combination valve stops them from locking until you are almost
> > > stopped even if you really mash the pedal down.
> > >
> > > Mike
> > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > > 88 Cherokee 235 BFG AT's
> > >
> > > Bob wrote:
> > > >
> > > > Hey...I am about to pull my brakes apart due to some persistent brake
> > > > fade issues (dry or wet) I've been having with my rear brakes; I want
> > > > to make sure everything is ok/fix whatever's wrong with them.
> > > >
> > > > Anyway, I'm going to start scouring the 'Net tonight to look for info
> > > > how to work on brakes, diagrams, instructions, etc., especially for
> > > > the rear drums (the front discs are more straight-forward from what I
> > > > understand, and I'm pretty sure I'll be able to figure out what's
> > > > going on with them a little easier).
> > > >
> > > > So, if anyone out there can provide me with any links to instructions
> > > > they've found particularly useful in the past, that would be awesome.
> > > > Pictures and diagrams are great, too. Bill, if you feel inclined to
> > > > put up a link to the appropriate section from the FSM or something,
> > > > that'd be awesome too. Also, any tips or suggestions what all I should
> > > > do when servicing and checking my brakes (beyond the obvious
> > > > inspection and replacement if necessary of the pads...) would be
> > > > great!
> > > >
> > > > Thanks everyone.
> > > >
> > > > /Bob
> > > >
> > > > Applicable specs:
> > > > 1997 TJ
> > > > Dana 44 Rear (drum brakes)
> > > > Dana 30 Front (disc brakes)
> > > > Stock brakes front and rear.
> > > > Last brake service performed 15 months ago.

 

Are you referring to the little "star" adjustment thingy or whatever?
How do I adjust this? I seem to remember seeing the guy at the brake
shop stick a screwdriver through the backing plate somewhere, but I
don't want to just randomly stick a screwdriver through one of the
backing plate holes without knowing what I'm aiming for ;-)

Thanks


"CRWLR" <beerman@yahoo.com> wrote in message news:<10e40r55hdoc08f@corp.supernews.com>...
> It sounds like you just need to adjust the brakes.
>
>
>
>
>
> "Bob" <magicclaw@mac.com> wrote in message
> news:47b769ae.0406290542.39c0c1a4@posting.google.c om...
> > I'm pretty sure it's not just that.
> >
> > I've been getting a seat-of-the-pants feeling that my braking power
> > has diminished of late; on the highway when traffic has stopped
> > suddenly, I've found myself having to smash down on the brakes harder
> > than before to get the jeep to stop in the same amount of time. While
> > I can still lock the front up, it just doesn't seem to be as
> > effective.
> >
> > This last weekend on the trail was my final straw: I was on a slight
> > incline, and tried to go up a couple of rocks (I was in 2wd), and spun
> > tires. So, I put the clutch in and hit the brake simultaneously, in
> > order to put it in 4-low to get through the little bit of rocks. As
> > soon as the clutch was in, the vehicle proceeded to roll back about
> > 10+ feet, with me standing on the brake pedal (in retrospect, perhaps
> > I should have pumped it). Either way, it was a bit freaky. The others
> > in my group said my front wheels were locked up, but my rears were
> > rolling, as I just rolled backward. It was like my rear brakes were
> > doing nothing, and just the locking-up and subsequent dragging of my
> > front wheels was all that stopped me.
> >
> > The braking improved a bit as the day progressed, but I decided maybe
> > I'd better check and see if the brakes were (a) in good shape still
> > and (b) not out of adjustment.
> >
> >
> > Mike Romain <romainm@sympatico.ca> wrote in message
> news:<40E08500.A9E6738F@sympatico.ca>...
> > > Are you sure you aren't just seeing the effects of a properly working
> > > combination valve?
> > >
> > > It acts like an anti lock brake for the rear wheels so they don't lock
> > > up easy if at all. Normally you don't want the rears locking, you can
> > > do 360's faster than you can blink if the rears lock up at speed.
> > >
> > > The combination valve stops them from locking until you are almost
> > > stopped even if you really mash the pedal down.
> > >
> > > Mike
> > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > > 88 Cherokee 235 BFG AT's
> > >
> > > Bob wrote:
> > > >
> > > > Hey...I am about to pull my brakes apart due to some persistent brake
> > > > fade issues (dry or wet) I've been having with my rear brakes; I want
> > > > to make sure everything is ok/fix whatever's wrong with them.
> > > >
> > > > Anyway, I'm going to start scouring the 'Net tonight to look for info
> > > > how to work on brakes, diagrams, instructions, etc., especially for
> > > > the rear drums (the front discs are more straight-forward from what I
> > > > understand, and I'm pretty sure I'll be able to figure out what's
> > > > going on with them a little easier).
> > > >
> > > > So, if anyone out there can provide me with any links to instructions
> > > > they've found particularly useful in the past, that would be awesome.
> > > > Pictures and diagrams are great, too. Bill, if you feel inclined to
> > > > put up a link to the appropriate section from the FSM or something,
> > > > that'd be awesome too. Also, any tips or suggestions what all I should
> > > > do when servicing and checking my brakes (beyond the obvious
> > > > inspection and replacement if necessary of the pads...) would be
> > > > great!
> > > >
> > > > Thanks everyone.
> > > >
> > > > /Bob
> > > >
> > > > Applicable specs:
> > > > 1997 TJ
> > > > Dana 44 Rear (drum brakes)
> > > > Dana 30 Front (disc brakes)
> > > > Stock brakes front and rear.
> > > > Last brake service performed 15 months ago.

 

Are you referring to the little "star" adjustment thingy or whatever?
How do I adjust this? I seem to remember seeing the guy at the brake
shop stick a screwdriver through the backing plate somewhere, but I
don't want to just randomly stick a screwdriver through one of the
backing plate holes without knowing what I'm aiming for ;-)

Thanks


"CRWLR" <beerman@yahoo.com> wrote in message news:<10e40r55hdoc08f@corp.supernews.com>...
> It sounds like you just need to adjust the brakes.
>
>
>
>
>
> "Bob" <magicclaw@mac.com> wrote in message
> news:47b769ae.0406290542.39c0c1a4@posting.google.c om...
> > I'm pretty sure it's not just that.
> >
> > I've been getting a seat-of-the-pants feeling that my braking power
> > has diminished of late; on the highway when traffic has stopped
> > suddenly, I've found myself having to smash down on the brakes harder
> > than before to get the jeep to stop in the same amount of time. While
> > I can still lock the front up, it just doesn't seem to be as
> > effective.
> >
> > This last weekend on the trail was my final straw: I was on a slight
> > incline, and tried to go up a couple of rocks (I was in 2wd), and spun
> > tires. So, I put the clutch in and hit the brake simultaneously, in
> > order to put it in 4-low to get through the little bit of rocks. As
> > soon as the clutch was in, the vehicle proceeded to roll back about
> > 10+ feet, with me standing on the brake pedal (in retrospect, perhaps
> > I should have pumped it). Either way, it was a bit freaky. The others
> > in my group said my front wheels were locked up, but my rears were
> > rolling, as I just rolled backward. It was like my rear brakes were
> > doing nothing, and just the locking-up and subsequent dragging of my
> > front wheels was all that stopped me.
> >
> > The braking improved a bit as the day progressed, but I decided maybe
> > I'd better check and see if the brakes were (a) in good shape still
> > and (b) not out of adjustment.
> >
> >
> > Mike Romain <romainm@sympatico.ca> wrote in message
> news:<40E08500.A9E6738F@sympatico.ca>...
> > > Are you sure you aren't just seeing the effects of a properly working
> > > combination valve?
> > >
> > > It acts like an anti lock brake for the rear wheels so they don't lock
> > > up easy if at all. Normally you don't want the rears locking, you can
> > > do 360's faster than you can blink if the rears lock up at speed.
> > >
> > > The combination valve stops them from locking until you are almost
> > > stopped even if you really mash the pedal down.
> > >
> > > Mike
> > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > > 88 Cherokee 235 BFG AT's
> > >
> > > Bob wrote:
> > > >
> > > > Hey...I am about to pull my brakes apart due to some persistent brake
> > > > fade issues (dry or wet) I've been having with my rear brakes; I want
> > > > to make sure everything is ok/fix whatever's wrong with them.
> > > >
> > > > Anyway, I'm going to start scouring the 'Net tonight to look for info
> > > > how to work on brakes, diagrams, instructions, etc., especially for
> > > > the rear drums (the front discs are more straight-forward from what I
> > > > understand, and I'm pretty sure I'll be able to figure out what's
> > > > going on with them a little easier).
> > > >
> > > > So, if anyone out there can provide me with any links to instructions
> > > > they've found particularly useful in the past, that would be awesome.
> > > > Pictures and diagrams are great, too. Bill, if you feel inclined to
> > > > put up a link to the appropriate section from the FSM or something,
> > > > that'd be awesome too. Also, any tips or suggestions what all I should
> > > > do when servicing and checking my brakes (beyond the obvious
> > > > inspection and replacement if necessary of the pads...) would be
> > > > great!
> > > >
> > > > Thanks everyone.
> > > >
> > > > /Bob
> > > >
> > > > Applicable specs:
> > > > 1997 TJ
> > > > Dana 44 Rear (drum brakes)
> > > > Dana 30 Front (disc brakes)
> > > > Stock brakes front and rear.
> > > > Last brake service performed 15 months ago.

 

Are you referring to the little "star" adjustment thingy or whatever?
How do I adjust this? I seem to remember seeing the guy at the brake
shop stick a screwdriver through the backing plate somewhere, but I
don't want to just randomly stick a screwdriver through one of the
backing plate holes without knowing what I'm aiming for ;-)

Thanks


"CRWLR" <beerman@yahoo.com> wrote in message news:<10e40r55hdoc08f@corp.supernews.com>...
> It sounds like you just need to adjust the brakes.
>
>
>
>
>
> "Bob" <magicclaw@mac.com> wrote in message
> news:47b769ae.0406290542.39c0c1a4@posting.google.c om...
> > I'm pretty sure it's not just that.
> >
> > I've been getting a seat-of-the-pants feeling that my braking power
> > has diminished of late; on the highway when traffic has stopped
> > suddenly, I've found myself having to smash down on the brakes harder
> > than before to get the jeep to stop in the same amount of time. While
> > I can still lock the front up, it just doesn't seem to be as
> > effective.
> >
> > This last weekend on the trail was my final straw: I was on a slight
> > incline, and tried to go up a couple of rocks (I was in 2wd), and spun
> > tires. So, I put the clutch in and hit the brake simultaneously, in
> > order to put it in 4-low to get through the little bit of rocks. As
> > soon as the clutch was in, the vehicle proceeded to roll back about
> > 10+ feet, with me standing on the brake pedal (in retrospect, perhaps
> > I should have pumped it). Either way, it was a bit freaky. The others
> > in my group said my front wheels were locked up, but my rears were
> > rolling, as I just rolled backward. It was like my rear brakes were
> > doing nothing, and just the locking-up and subsequent dragging of my
> > front wheels was all that stopped me.
> >
> > The braking improved a bit as the day progressed, but I decided maybe
> > I'd better check and see if the brakes were (a) in good shape still
> > and (b) not out of adjustment.
> >
> >
> > Mike Romain <romainm@sympatico.ca> wrote in message
> news:<40E08500.A9E6738F@sympatico.ca>...
> > > Are you sure you aren't just seeing the effects of a properly working
> > > combination valve?
> > >
> > > It acts like an anti lock brake for the rear wheels so they don't lock
> > > up easy if at all. Normally you don't want the rears locking, you can
> > > do 360's faster than you can blink if the rears lock up at speed.
> > >
> > > The combination valve stops them from locking until you are almost
> > > stopped even if you really mash the pedal down.
> > >
> > > Mike
> > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > > 88 Cherokee 235 BFG AT's
> > >
> > > Bob wrote:
> > > >
> > > > Hey...I am about to pull my brakes apart due to some persistent brake
> > > > fade issues (dry or wet) I've been having with my rear brakes; I want
> > > > to make sure everything is ok/fix whatever's wrong with them.
> > > >
> > > > Anyway, I'm going to start scouring the 'Net tonight to look for info
> > > > how to work on brakes, diagrams, instructions, etc., especially for
> > > > the rear drums (the front discs are more straight-forward from what I
> > > > understand, and I'm pretty sure I'll be able to figure out what's
> > > > going on with them a little easier).
> > > >
> > > > So, if anyone out there can provide me with any links to instructions
> > > > they've found particularly useful in the past, that would be awesome.
> > > > Pictures and diagrams are great, too. Bill, if you feel inclined to
> > > > put up a link to the appropriate section from the FSM or something,
> > > > that'd be awesome too. Also, any tips or suggestions what all I should
> > > > do when servicing and checking my brakes (beyond the obvious
> > > > inspection and replacement if necessary of the pads...) would be
> > > > great!
> > > >
> > > > Thanks everyone.
> > > >
> > > > /Bob
> > > >
> > > > Applicable specs:
> > > > 1997 TJ
> > > > Dana 44 Rear (drum brakes)
> > > > Dana 30 Front (disc brakes)
> > > > Stock brakes front and rear.
> > > > Last brake service performed 15 months ago.

 

I do appreciate the comments. However, I do understand the utility of
the low range for slowing down the movement of the axles. In the case
I described, though, the issue would have occured regardless of
whether I was in high or low range, as it occurred when I was going
forward, then had to stop and put the clutch in. If I had been in
4low, I still would have rolled backward in the same way when I
stopped my forward motion and put the clutch in. It's not like I
would've tried to hurry and put it in reverse to use the engine
braking; I expect, when I'm at a near standstill trying to go forward,
that if I push in the clutch and the brake at the same time to stop,
I'm not going to randomly roll back ten feet if I don't slam the thing
into reverse and pull the clutch out as some sort of preventative
measure.

Your statement was not bad advice by any means, just not applicable to
the situation I was in. (This trail was not difficult, either; I'd
been in 2wd for awhile so I could move faster; I don't like running in
3rd and 4th gear while in low range...my 4.56 diff gearing makes it
difficult to keep up on an easy faster paced trail if I stay in low
range sometimes.) Sure, I probably should have shifted into 4-low
before trying the rocks (I could tell I'd probably not make it in
2-high), but I was in the mood to play a little and give it a shot in
2wd for kicks. I was surprised by the resulting brake crapping out
when I had to give up and wanted to shift into 4-low, though.

/Bob


"mabar" <mabar@NoSpamgrbonline.com> wrote in message news:<aIidnWg5F6f7lH_d4p2dnA@gbronline.com>...
> Hi Bob:
>
> Drum brakes have a "self-energizing" action while braking in forward mode.
> The brake shoes actually "dig into" the drum harder when braking in forward
> motion. There is no "self-energizing action" in rear motion braking on
> drums. So when braking when backing down a hill for example you have almost
> NO rear braking action. Applying the parking brake will help but you want to
> be very careful doing that as that can easily lock up the rears which might
> cause complete loss of vehicle control.
>
> If you are in 4-hi or 4-lo on a part-time 4-wheel drive system like the TJ
> or YJ, the front and rear axels are mechanically locked together and the
> front brakes will actually stop the rear wheels through the drive train.
> It's very important for good vehicle control on off-road hills to be in 4-
> wheel drive, preferably low range. That way the engine does most of the
> braking and brakes all 4 wheels through the drive train and you can just
> apply gentle pressure to the brake pedal to control the descent WITHOUT
> locking up the wheels and loosing control.
>
> Tom
>
> "Bob" <magicclaw@mac.com> wrote in message
> news:47b769ae.0406290542.39c0c1a4@posting.google.c om...
> > I'm pretty sure it's not just that.
> >
> > I've been getting a seat-of-the-pants feeling that my braking power
> > has diminished of late; on the highway when traffic has stopped
> > suddenly, I've found myself having to smash down on the brakes harder
> > than before to get the jeep to stop in the same amount of time. While
> > I can still lock the front up, it just doesn't seem to be as
> > effective.
> >
> > This last weekend on the trail was my final straw: I was on a slight
> > incline, and tried to go up a couple of rocks (I was in 2wd), and spun
> > tires. So, I put the clutch in and hit the brake simultaneously, in
> > order to put it in 4-low to get through the little bit of rocks. As
> > soon as the clutch was in, the vehicle proceeded to roll back about
> > 10+ feet, with me standing on the brake pedal (in retrospect, perhaps
> > I should have pumped it). Either way, it was a bit freaky. The others
> > in my group said my front wheels were locked up, but my rears were
> > rolling, as I just rolled backward. It was like my rear brakes were
> > doing nothing, and just the locking-up and subsequent dragging of my
> > front wheels was all that stopped me.
> >
> > The braking improved a bit as the day progressed, but I decided maybe
> > I'd better check and see if the brakes were (a) in good shape still
> > and (b) not out of adjustment.
> >

 

I do appreciate the comments. However, I do understand the utility of
the low range for slowing down the movement of the axles. In the case
I described, though, the issue would have occured regardless of
whether I was in high or low range, as it occurred when I was going
forward, then had to stop and put the clutch in. If I had been in
4low, I still would have rolled backward in the same way when I
stopped my forward motion and put the clutch in. It's not like I
would've tried to hurry and put it in reverse to use the engine
braking; I expect, when I'm at a near standstill trying to go forward,
that if I push in the clutch and the brake at the same time to stop,
I'm not going to randomly roll back ten feet if I don't slam the thing
into reverse and pull the clutch out as some sort of preventative
measure.

Your statement was not bad advice by any means, just not applicable to
the situation I was in. (This trail was not difficult, either; I'd
been in 2wd for awhile so I could move faster; I don't like running in
3rd and 4th gear while in low range...my 4.56 diff gearing makes it
difficult to keep up on an easy faster paced trail if I stay in low
range sometimes.) Sure, I probably should have shifted into 4-low
before trying the rocks (I could tell I'd probably not make it in
2-high), but I was in the mood to play a little and give it a shot in
2wd for kicks. I was surprised by the resulting brake crapping out
when I had to give up and wanted to shift into 4-low, though.

/Bob


"mabar" <mabar@NoSpamgrbonline.com> wrote in message news:<aIidnWg5F6f7lH_d4p2dnA@gbronline.com>...
> Hi Bob:
>
> Drum brakes have a "self-energizing" action while braking in forward mode.
> The brake shoes actually "dig into" the drum harder when braking in forward
> motion. There is no "self-energizing action" in rear motion braking on
> drums. So when braking when backing down a hill for example you have almost
> NO rear braking action. Applying the parking brake will help but you want to
> be very careful doing that as that can easily lock up the rears which might
> cause complete loss of vehicle control.
>
> If you are in 4-hi or 4-lo on a part-time 4-wheel drive system like the TJ
> or YJ, the front and rear axels are mechanically locked together and the
> front brakes will actually stop the rear wheels through the drive train.
> It's very important for good vehicle control on off-road hills to be in 4-
> wheel drive, preferably low range. That way the engine does most of the
> braking and brakes all 4 wheels through the drive train and you can just
> apply gentle pressure to the brake pedal to control the descent WITHOUT
> locking up the wheels and loosing control.
>
> Tom
>
> "Bob" <magicclaw@mac.com> wrote in message
> news:47b769ae.0406290542.39c0c1a4@posting.google.c om...
> > I'm pretty sure it's not just that.
> >
> > I've been getting a seat-of-the-pants feeling that my braking power
> > has diminished of late; on the highway when traffic has stopped
> > suddenly, I've found myself having to smash down on the brakes harder
> > than before to get the jeep to stop in the same amount of time. While
> > I can still lock the front up, it just doesn't seem to be as
> > effective.
> >
> > This last weekend on the trail was my final straw: I was on a slight
> > incline, and tried to go up a couple of rocks (I was in 2wd), and spun
> > tires. So, I put the clutch in and hit the brake simultaneously, in
> > order to put it in 4-low to get through the little bit of rocks. As
> > soon as the clutch was in, the vehicle proceeded to roll back about
> > 10+ feet, with me standing on the brake pedal (in retrospect, perhaps
> > I should have pumped it). Either way, it was a bit freaky. The others
> > in my group said my front wheels were locked up, but my rears were
> > rolling, as I just rolled backward. It was like my rear brakes were
> > doing nothing, and just the locking-up and subsequent dragging of my
> > front wheels was all that stopped me.
> >
> > The braking improved a bit as the day progressed, but I decided maybe
> > I'd better check and see if the brakes were (a) in good shape still
> > and (b) not out of adjustment.
> >

 

I do appreciate the comments. However, I do understand the utility of
the low range for slowing down the movement of the axles. In the case
I described, though, the issue would have occured regardless of
whether I was in high or low range, as it occurred when I was going
forward, then had to stop and put the clutch in. If I had been in
4low, I still would have rolled backward in the same way when I
stopped my forward motion and put the clutch in. It's not like I
would've tried to hurry and put it in reverse to use the engine
braking; I expect, when I'm at a near standstill trying to go forward,
that if I push in the clutch and the brake at the same time to stop,
I'm not going to randomly roll back ten feet if I don't slam the thing
into reverse and pull the clutch out as some sort of preventative
measure.

Your statement was not bad advice by any means, just not applicable to
the situation I was in. (This trail was not difficult, either; I'd
been in 2wd for awhile so I could move faster; I don't like running in
3rd and 4th gear while in low range...my 4.56 diff gearing makes it
difficult to keep up on an easy faster paced trail if I stay in low
range sometimes.) Sure, I probably should have shifted into 4-low
before trying the rocks (I could tell I'd probably not make it in
2-high), but I was in the mood to play a little and give it a shot in
2wd for kicks. I was surprised by the resulting brake crapping out
when I had to give up and wanted to shift into 4-low, though.

/Bob


"mabar" <mabar@NoSpamgrbonline.com> wrote in message news:<aIidnWg5F6f7lH_d4p2dnA@gbronline.com>...
> Hi Bob:
>
> Drum brakes have a "self-energizing" action while braking in forward mode.
> The brake shoes actually "dig into" the drum harder when braking in forward
> motion. There is no "self-energizing action" in rear motion braking on
> drums. So when braking when backing down a hill for example you have almost
> NO rear braking action. Applying the parking brake will help but you want to
> be very careful doing that as that can easily lock up the rears which might
> cause complete loss of vehicle control.
>
> If you are in 4-hi or 4-lo on a part-time 4-wheel drive system like the TJ
> or YJ, the front and rear axels are mechanically locked together and the
> front brakes will actually stop the rear wheels through the drive train.
> It's very important for good vehicle control on off-road hills to be in 4-
> wheel drive, preferably low range. That way the engine does most of the
> braking and brakes all 4 wheels through the drive train and you can just
> apply gentle pressure to the brake pedal to control the descent WITHOUT
> locking up the wheels and loosing control.
>
> Tom
>
> "Bob" <magicclaw@mac.com> wrote in message
> news:47b769ae.0406290542.39c0c1a4@posting.google.c om...
> > I'm pretty sure it's not just that.
> >
> > I've been getting a seat-of-the-pants feeling that my braking power
> > has diminished of late; on the highway when traffic has stopped
> > suddenly, I've found myself having to smash down on the brakes harder
> > than before to get the jeep to stop in the same amount of time. While
> > I can still lock the front up, it just doesn't seem to be as
> > effective.
> >
> > This last weekend on the trail was my final straw: I was on a slight
> > incline, and tried to go up a couple of rocks (I was in 2wd), and spun
> > tires. So, I put the clutch in and hit the brake simultaneously, in
> > order to put it in 4-low to get through the little bit of rocks. As
> > soon as the clutch was in, the vehicle proceeded to roll back about
> > 10+ feet, with me standing on the brake pedal (in retrospect, perhaps
> > I should have pumped it). Either way, it was a bit freaky. The others
> > in my group said my front wheels were locked up, but my rears were
> > rolling, as I just rolled backward. It was like my rear brakes were
> > doing nothing, and just the locking-up and subsequent dragging of my
> > front wheels was all that stopped me.
> >
> > The braking improved a bit as the day progressed, but I decided maybe
> > I'd better check and see if the brakes were (a) in good shape still
> > and (b) not out of adjustment.
> >