Re: highway speed in full time 4X4?
 

On 07 Jan 2004 06:50 AM, Bob posted the following:

> And what are you talking about with the "Jeeps especially have rear
> antilock brakes" statement? Yeah, sure, it's available as an option,
> but I think a large majority of jeeps, and know a large majority of
> CARS out there don't necessarily have antilock rear brakes. (I sure as
> heck don't have antilock rear brakes on my D44!)

According to Mike, the proportioning valve should be classified as an
ABS system, which it is not.

----------------------------------------------------
Del Rawlins- del@_kills_spammers_rawlinsbrothers.org
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

Re: highway speed in full time 4X4?
 

Del Rawlins wrote:
>
> On 07 Jan 2004 06:50 AM, Bob posted the following:
>
> > And what are you talking about with the "Jeeps especially have rear
> > antilock brakes" statement? Yeah, sure, it's available as an option,
> > but I think a large majority of jeeps, and know a large majority of
> > CARS out there don't necessarily have antilock rear brakes. (I sure as
> > heck don't have antilock rear brakes on my D44!)
>
> According to Mike, the proportioning valve should be classified as an
> ABS system, which it is not.
>
> ----------------------------------------------------

Del, do you know why they put a combination valve in Jeeps?

Hint: It isn't just there to make bleeding the brakes a pain in the
butt.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Re: highway speed in full time 4X4?
 

Del Rawlins wrote:
>
> On 07 Jan 2004 06:50 AM, Bob posted the following:
>
> > And what are you talking about with the "Jeeps especially have rear
> > antilock brakes" statement? Yeah, sure, it's available as an option,
> > but I think a large majority of jeeps, and know a large majority of
> > CARS out there don't necessarily have antilock rear brakes. (I sure as
> > heck don't have antilock rear brakes on my D44!)
>
> According to Mike, the proportioning valve should be classified as an
> ABS system, which it is not.
>
> ----------------------------------------------------

Del, do you know why they put a combination valve in Jeeps?

Hint: It isn't just there to make bleeding the brakes a pain in the
butt.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Re: highway speed in full time 4X4?
 

Del Rawlins wrote:
>
> On 07 Jan 2004 06:50 AM, Bob posted the following:
>
> > And what are you talking about with the "Jeeps especially have rear
> > antilock brakes" statement? Yeah, sure, it's available as an option,
> > but I think a large majority of jeeps, and know a large majority of
> > CARS out there don't necessarily have antilock rear brakes. (I sure as
> > heck don't have antilock rear brakes on my D44!)
>
> According to Mike, the proportioning valve should be classified as an
> ABS system, which it is not.
>
> ----------------------------------------------------

Del, do you know why they put a combination valve in Jeeps?

Hint: It isn't just there to make bleeding the brakes a pain in the
butt.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Re: highway speed in full time 4X4?
 

On Wed, 7 Jan 2004 16:15:21 UTC Mike Romain <romainm@sympatico.ca>
wrote:

> I can lock them up for the last 2 or 3 feet of a stop if I have all my
> 200 lb on it, but no way they will lock at speed.
>
> That is what that valve is specifically for.
>
> Locking the rear wheels at speed causes instant 360's. Try mashing the
> e-brake on while driving 50 mph across an empty parking lot or on a
> frozen lake.
>
> We actually use this method for getting around corners fast when ice
> racing, especially in front wheel drive cars.

That's probably more a function of the particular valve than an
inherent characteristic of the system. Most of my observations on the
antilock brakes actually comes from pickups where load sensing
adjusters are common as well, so that will make a difference. The day
I forgot to reconnect the load sensor lever and tried to stop when the
MJ was empty with the load sensor saying I was on the bump stops was
highly enlightening, to say the least <g>. Those proportioners are
really a very simple regulator that keep the pressure differential
front-to-rear at some pretty much fixed ratio so in theory you can
lock everything solid but as you point out it's not easy.

That little trick with the emergency brake is useful in a lot of
places but the foot operated ebrake makes it a real PITA to use. I've
looked at replacing mine with the hand-operated type several times but
haven't actually tried to change it over. For me, I almost have to
open the door to have enough room to clear the steering wheel when
applying the ebrake. Plus, it's hard to feather how much braking you
get with it. Combined with a manual tranny it makes for 4 pedals and
only 2 feet. Now add in the release lever and you have 4 pedals, 2
levers, and 1 steering wheel - all ------ out in exactly the wrong
relative positions for only 2 feet and 2 hands. ARRGGH!

All of my kids have been run thru the exercise of that rear ebrake on
a long, wide runway. It is a real eye opener for them when you tell
them to stop from 60mph or so using ONLY the ebrake.

--
Will Honea <whonea@codenet.net>

Re: highway speed in full time 4X4?
 

On Wed, 7 Jan 2004 16:15:21 UTC Mike Romain <romainm@sympatico.ca>
wrote:

> I can lock them up for the last 2 or 3 feet of a stop if I have all my
> 200 lb on it, but no way they will lock at speed.
>
> That is what that valve is specifically for.
>
> Locking the rear wheels at speed causes instant 360's. Try mashing the
> e-brake on while driving 50 mph across an empty parking lot or on a
> frozen lake.
>
> We actually use this method for getting around corners fast when ice
> racing, especially in front wheel drive cars.

That's probably more a function of the particular valve than an
inherent characteristic of the system. Most of my observations on the
antilock brakes actually comes from pickups where load sensing
adjusters are common as well, so that will make a difference. The day
I forgot to reconnect the load sensor lever and tried to stop when the
MJ was empty with the load sensor saying I was on the bump stops was
highly enlightening, to say the least <g>. Those proportioners are
really a very simple regulator that keep the pressure differential
front-to-rear at some pretty much fixed ratio so in theory you can
lock everything solid but as you point out it's not easy.

That little trick with the emergency brake is useful in a lot of
places but the foot operated ebrake makes it a real PITA to use. I've
looked at replacing mine with the hand-operated type several times but
haven't actually tried to change it over. For me, I almost have to
open the door to have enough room to clear the steering wheel when
applying the ebrake. Plus, it's hard to feather how much braking you
get with it. Combined with a manual tranny it makes for 4 pedals and
only 2 feet. Now add in the release lever and you have 4 pedals, 2
levers, and 1 steering wheel - all ------ out in exactly the wrong
relative positions for only 2 feet and 2 hands. ARRGGH!

All of my kids have been run thru the exercise of that rear ebrake on
a long, wide runway. It is a real eye opener for them when you tell
them to stop from 60mph or so using ONLY the ebrake.

--
Will Honea <whonea@codenet.net>

Re: highway speed in full time 4X4?
 

On Wed, 7 Jan 2004 16:15:21 UTC Mike Romain <romainm@sympatico.ca>
wrote:

> I can lock them up for the last 2 or 3 feet of a stop if I have all my
> 200 lb on it, but no way they will lock at speed.
>
> That is what that valve is specifically for.
>
> Locking the rear wheels at speed causes instant 360's. Try mashing the
> e-brake on while driving 50 mph across an empty parking lot or on a
> frozen lake.
>
> We actually use this method for getting around corners fast when ice
> racing, especially in front wheel drive cars.

That's probably more a function of the particular valve than an
inherent characteristic of the system. Most of my observations on the
antilock brakes actually comes from pickups where load sensing
adjusters are common as well, so that will make a difference. The day
I forgot to reconnect the load sensor lever and tried to stop when the
MJ was empty with the load sensor saying I was on the bump stops was
highly enlightening, to say the least <g>. Those proportioners are
really a very simple regulator that keep the pressure differential
front-to-rear at some pretty much fixed ratio so in theory you can
lock everything solid but as you point out it's not easy.

That little trick with the emergency brake is useful in a lot of
places but the foot operated ebrake makes it a real PITA to use. I've
looked at replacing mine with the hand-operated type several times but
haven't actually tried to change it over. For me, I almost have to
open the door to have enough room to clear the steering wheel when
applying the ebrake. Plus, it's hard to feather how much braking you
get with it. Combined with a manual tranny it makes for 4 pedals and
only 2 feet. Now add in the release lever and you have 4 pedals, 2
levers, and 1 steering wheel - all ------ out in exactly the wrong
relative positions for only 2 feet and 2 hands. ARRGGH!

All of my kids have been run thru the exercise of that rear ebrake on
a long, wide runway. It is a real eye opener for them when you tell
them to stop from 60mph or so using ONLY the ebrake.

--
Will Honea <whonea@codenet.net>

Re: highway speed in full time 4X4?
 

Del Rawlins wrote:
>
> On 07 Jan 2004 07:10 AM, Mike Romain posted the following:
> > Del Rawlins wrote:
> >>
> >> On 06 Jan 2004 11:40 AM, Mike Romain posted the following:
> >>
> >> > Jeeps especially
> >> > have rear anti lock brakes, have since the 70's.
> >>
> >> Not.
> >>
> >
> > Yup, they started using a combination valve in utility vehicles like
> > Jeeps, pickups and station wagons back in the 70's and it 'was'
> > advertised as rear anti lock brakes and said it prevented rear wheel
> > lock to allow straight line panic braking.
> >
> > They didn't call it 'ABS', that is a new term.
>
> They didn't call it ABS, because it isn't an ABS system. It works
> toward the same goal, but the difference in how it gets there is
> important. ABS uses wheel speed sensors, a control unit and a modulator.
> The combination valve is just a valve. You can call it whatever you
> like but that doesn't make it so.
>
> > I just had this discussion with someone else here and I quoted the
> > books.
>
> Which books?
>
> ----------------------------------------------------

Del, there is one reason and one reason only for the proportioning valve
part of the combination valve they put in Jeeps, pickups, SUV's, etc.

That is, to quote the Haynes manual, "The proportioner section provides
balanced front-to-rear pressure during hard braking, reducing the rear
line pressure so the wheels don't lock up."

Simple eh?

And they even managed to do it before computers.

Well crap Del, I just went and looked and it was you that didn't believe
what a proportioning valve was for in the post I am referring to.

I am sorry if you can't grasp the basics of this valve, but there is
absolutely no other use for it 'Except' to prevent rear wheel lock under
hard braking.

I am not going to argue this further with you. I provided book quotes
to you before and have tried to explain it.

If you don't believe it, take the sucker out and try your brakes or even
easier start using your e-brake to stop and see what happens.

Or try to come up with something in writing that refutes what I have
posted both here and in the last thread on this.

I am not mistaken on this.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Re: highway speed in full time 4X4?
 

Del Rawlins wrote:
>
> On 07 Jan 2004 07:10 AM, Mike Romain posted the following:
> > Del Rawlins wrote:
> >>
> >> On 06 Jan 2004 11:40 AM, Mike Romain posted the following:
> >>
> >> > Jeeps especially
> >> > have rear anti lock brakes, have since the 70's.
> >>
> >> Not.
> >>
> >
> > Yup, they started using a combination valve in utility vehicles like
> > Jeeps, pickups and station wagons back in the 70's and it 'was'
> > advertised as rear anti lock brakes and said it prevented rear wheel
> > lock to allow straight line panic braking.
> >
> > They didn't call it 'ABS', that is a new term.
>
> They didn't call it ABS, because it isn't an ABS system. It works
> toward the same goal, but the difference in how it gets there is
> important. ABS uses wheel speed sensors, a control unit and a modulator.
> The combination valve is just a valve. You can call it whatever you
> like but that doesn't make it so.
>
> > I just had this discussion with someone else here and I quoted the
> > books.
>
> Which books?
>
> ----------------------------------------------------

Del, there is one reason and one reason only for the proportioning valve
part of the combination valve they put in Jeeps, pickups, SUV's, etc.

That is, to quote the Haynes manual, "The proportioner section provides
balanced front-to-rear pressure during hard braking, reducing the rear
line pressure so the wheels don't lock up."

Simple eh?

And they even managed to do it before computers.

Well crap Del, I just went and looked and it was you that didn't believe
what a proportioning valve was for in the post I am referring to.

I am sorry if you can't grasp the basics of this valve, but there is
absolutely no other use for it 'Except' to prevent rear wheel lock under
hard braking.

I am not going to argue this further with you. I provided book quotes
to you before and have tried to explain it.

If you don't believe it, take the sucker out and try your brakes or even
easier start using your e-brake to stop and see what happens.

Or try to come up with something in writing that refutes what I have
posted both here and in the last thread on this.

I am not mistaken on this.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Re: highway speed in full time 4X4?
 

Del Rawlins wrote:
>
> On 07 Jan 2004 07:10 AM, Mike Romain posted the following:
> > Del Rawlins wrote:
> >>
> >> On 06 Jan 2004 11:40 AM, Mike Romain posted the following:
> >>
> >> > Jeeps especially
> >> > have rear anti lock brakes, have since the 70's.
> >>
> >> Not.
> >>
> >
> > Yup, they started using a combination valve in utility vehicles like
> > Jeeps, pickups and station wagons back in the 70's and it 'was'
> > advertised as rear anti lock brakes and said it prevented rear wheel
> > lock to allow straight line panic braking.
> >
> > They didn't call it 'ABS', that is a new term.
>
> They didn't call it ABS, because it isn't an ABS system. It works
> toward the same goal, but the difference in how it gets there is
> important. ABS uses wheel speed sensors, a control unit and a modulator.
> The combination valve is just a valve. You can call it whatever you
> like but that doesn't make it so.
>
> > I just had this discussion with someone else here and I quoted the
> > books.
>
> Which books?
>
> ----------------------------------------------------

Del, there is one reason and one reason only for the proportioning valve
part of the combination valve they put in Jeeps, pickups, SUV's, etc.

That is, to quote the Haynes manual, "The proportioner section provides
balanced front-to-rear pressure during hard braking, reducing the rear
line pressure so the wheels don't lock up."

Simple eh?

And they even managed to do it before computers.

Well crap Del, I just went and looked and it was you that didn't believe
what a proportioning valve was for in the post I am referring to.

I am sorry if you can't grasp the basics of this valve, but there is
absolutely no other use for it 'Except' to prevent rear wheel lock under
hard braking.

I am not going to argue this further with you. I provided book quotes
to you before and have tried to explain it.

If you don't believe it, take the sucker out and try your brakes or even
easier start using your e-brake to stop and see what happens.

Or try to come up with something in writing that refutes what I have
posted both here and in the last thread on this.

I am not mistaken on this.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's