[modern] 91 xj6 brakes

my 91 xj6 brakes are pulling bad. When I hit the brake
hard it pulls violently to the left. If I put slight
pressure on the pedal then brake hard, it works just
fine.
This has been a nagging problem for a year or so. I
have exersized the solinoids (sp) while bleeding and
still no success.
Maybe I should try to back flush the ABS valves and
hope that may clear out the problem. There has been
plenty of good fluid flushed through the system so
debris should not be a problem.

Maybe I should replace the ABS block next.
I remember a while back that someone indicated that a
Cadillac had the same brake system. What Caddie was
that?
I might be able to get a good price for one of those.

Any help would be great

Thanks

Dave
91 sov__________________________________________________
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Dave,
As Bryan says, I would check the calipers first, but if you find
you still have the problem, you can do any of the following…

Buy a new valve body…I found one for an XJS for $260.00.
If it does not fit up directly, you can swap the actual
valves or,

Buy one for a cadillac, late 80’s model I think.
Its the same teves system, but has the pump tilted
over more than the Jaguar setup, but the valves
are likely the same.

My car has had the problem, but since I put brakes on it
quite a few times and did not notice anything wrong
with the calipers, I suspect the valve body.
That and the fact of how VIOLENT the pulling is
on fast application of the brakes…
One side in the front obviously has NO brakes at all
under these conditions.
It also comes and goes, and is much better after
a fluid flush…

Still, checking/cleaning the calipers is on my list
of spring time projects…

Brett
1990 XJ6>

my 91 xj6 brakes are pulling bad. When I hit the brake
hard it pulls violently to the left. If I put slight
pressure on the pedal then brake hard, it works just
fine.
This has been a nagging problem for a year or so. I
have exersized the solinoids (sp) while bleeding and
still no success.
Maybe I should try to back flush the ABS valves and
hope that may clear out the problem. There has been
plenty of good fluid flushed through the system so
debris should not be a problem.

Maybe I should replace the ABS block next.
I remember a while back that someone indicated that a
Cadillac had the same brake system. What Caddie was
that?
I might be able to get a good price for one of those.

Any help would be great

Thanks

Dave
91 sov


Do You Yahoo!?
Yahoo! Movies - coverage of the 74th Academy Awards�
http://movies.yahoo.com/

This sounds like the problem that will sometimes occur with the Teves system
when the front brake pads are changed improperly. With the Teves system it
is very important to clamp the brake line at the caliper and then to open
the bleed screw before pushing the brake piston back. This way any dirt or
grit in the brake fluid is expelled from the system rather than being pushed
upstream into the ABS valving. The ABS valving cycles at a high rate (6-8
times per second) and the valves are very precisely made; any small bit of
grit or dirt in the valving can cause this to occur.

If the pull is very violent when it occurs, IMO the problem described is the
most likely cause.

Some people have reported success in fixing this by flushing a large amount
of brake fluid through the ABS valving; others have had to replace or repair
the ABS block to fix this. Jaguar does have a repair kit for the valving
IIRC, though none of these pieces are cheap.

Best regards,

Gregory Wells 800-331-2193 x103
Coventry West, Inc. - Atlanta, GA www.coventrywest.com
New, Rebuilt, and Used Jaguar & Land-Rover Parts

dave c wrote:> my 91 xj6 brakes are pulling bad. When I hit the brake

hard it pulls violently to the left. If I put slight
pressure on the pedal then brake hard, it works just
fine.

I should have read this note before seding the previous reply. Can I ask,
how do you clamp the brake line?-----Original Message-----
From: owner-modern@jag-lovers.org [mailto:owner-modern@jag-lovers.org]On
Behalf Of Gregory Wells
Sent: Wednesday, March 27, 2002 11:32 AM
To: modern@lyons.jag-lovers.org
Subject: RE: [modern] 91 xj6 brakes

This sounds like the problem that will sometimes occur with the Teves system
when the front brake pads are changed improperly. With the Teves system it
is very important to clamp the brake line at the caliper and then to open
the bleed screw before pushing the brake piston back. This way any dirt or
grit in the brake fluid is expelled from the system rather than being pushed
upstream into the ABS valving. The ABS valving cycles at a high rate (6-8
times per second) and the valves are very precisely made; any small bit of
grit or dirt in the valving can cause this to occur.

If the pull is very violent when it occurs, IMO the problem described is the
most likely cause.

Some people have reported success in fixing this by flushing a large amount
of brake fluid through the ABS valving; others have had to replace or repair
the ABS block to fix this. Jaguar does have a repair kit for the valving
IIRC, though none of these pieces are cheap.

Best regards,

Gregory Wells 800-331-2193 x103
Coventry West, Inc. - Atlanta, GA www.coventrywest.com
New, Rebuilt, and Used Jaguar & Land-Rover Parts

dave c wrote:

my 91 xj6 brakes are pulling bad. When I hit the brake
hard it pulls violently to the left. If I put slight
pressure on the pedal then brake hard, it works just
fine.

You can buy plastic clamps made for pinching hoses.
It is a good idea because when I did my '91 at 100,000, on the right rear
wheel, I opened the bleed screw, compressed the piston, and then realized
that the bleed screw was blocked. Everything has been OK, probably because
the rears are a long way from the valves. Make sure fluid is coming out the
bleed screw as you push the piston in.

In flushing the system, the bigger danger is running the tank dry. I tried
bleeding with the ignition completely off, me opening the bleeder and my
wife standing on the pedal. What a joke. So I had her turn the key to on -
which on the '91 turns on the pump that pressurizes the system. When she
stepped on the pedal I had a solid and rapid flow out the bleeder. Luckily
I had used a round plate and a spout that screws to the fluid
container–which came with my hand vacuum pump. You invert the brake fluid
container over the opening in the tank, through the plate. The spout is
about the right length to fill the tank without overflowing. As brake fluid
was pumped out the bleeder, the container of brake fluid rapidly emptied.-----Original Message-----
From: owner-modern@jag-lovers.org [mailto:owner-modern@jag-lovers.org]On
Behalf Of Mike Pukmel
Sent: Wednesday, March 27, 2002 2:47 PM
To: modern@lyons.jag-lovers.org
Subject: RE: [modern] 91 xj6 brakes

I should have read this note before seding the previous reply. Can I ask,
how do you clamp the brake line?

-----Original Message-----
From: owner-modern@jag-lovers.org [mailto:owner-modern@jag-lovers.org]On
Behalf Of Gregory Wells
Sent: Wednesday, March 27, 2002 11:32 AM
To: modern@lyons.jag-lovers.org
Subject: RE: [modern] 91 xj6 brakes

This sounds like the problem that will sometimes occur with the Teves system
when the front brake pads are changed improperly. With the Teves system it
is very important to clamp the brake line at the caliper and then to open
the bleed screw before pushing the brake piston back. This way any dirt or
grit in the brake fluid is expelled from the system rather than being pushed
upstream into the ABS valving. The ABS valving cycles at a high rate (6-8
times per second) and the valves are very precisely made; any small bit of
grit or dirt in the valving can cause this to occur.

If the pull is very violent when it occurs, IMO the problem described is the
most likely cause.

Some people have reported success in fixing this by flushing a large amount
of brake fluid through the ABS valving; others have had to replace or repair
the ABS block to fix this. Jaguar does have a repair kit for the valving
IIRC, though none of these pieces are cheap.

Best regards,

Gregory Wells 800-331-2193 x103
Coventry West, Inc. - Atlanta, GA www.coventrywest.com
New, Rebuilt, and Used Jaguar & Land-Rover Parts

dave c wrote:

my 91 xj6 brakes are pulling bad. When I hit the brake
hard it pulls violently to the left. If I put slight
pressure on the pedal then brake hard, it works just
fine.

At 05:47 PM 3/27/2002, you wrote:

I should have read this note before seding the previous reply. Can I ask,
how do you clamp the brake line?

The Vise-Grip company makes a lovely pair of Vise-Grips that have round
jaws specifically for clamping off flexible lines without biting into them.

Here’s the page to look them up and in case this doesn’t come up right,
they are stock number 29, Model RR pinch off clamping pliers.

http://www.visegrip.com/pi/toolSrch.asp

Jeb

I have sitting here rreading the discussion regarding brakes and ABS valves.

Having taken note of Brett’s advice over the past year in the list, when I
recently replaced my pads and rotors on my '88 I decided I should flush the
brakes as well.

Rather than go through all this to-do with clamps and bleeders and back flow
into the ABS system, I simply removed each caliper as I worked around the
car. With the caliper removed, it was easy to push the piston back as well
as check all the seals and re-grease the slide rods to make sure nothing was
hung up.

Once the piston was back, the caliper went back on easily and I replaced all
of the brake fluid, removing the obviously old brown fluid with new clear
fluid.

I do the same procedure with all my vehicles and I have never had a problem.
(Except for some smoke from the front rotors as the pads/fluid burned off
for the first 15 miles). No shimmer or shake or soft pedal.

I know the '91 is different than the '88, but I can’t see how you can go
wrong doing it this way as it gets you a chance to clean the system and
inspect everything with no chance of fluid back-up into the ABS valving.

Clark
'88 XJ40