LOST JEEPS :: View topic - My front brakes are worrying me...

HARD PEDAL OR HIGH PEDAL EFFORT
A hard pedal or high pedal effort may be due to
lining that is water soaked, contaminated, glazed, or
badly worn. The power booster or check valve could
also be faulty.

BRAKE PULL
Front brake pull condition could result from:
† Contaminated lining in one caliper
† Seized caliper piston
† Binding caliper
† Loose caliper
† Rusty caliper slide surfaces
† Improper brake shoes
† Damaged rotor
A worn, damaged wheel bearing or suspension
component are further causes of pull. A damaged
front tire (bruised, ply separation) can also cause
pull.
A common and frequently misdiagnosed pull condition
is where direction of pull changes after a few
stops. The cause is a combination of brake drag followed
by fade at one of the brake units.
As the dragging brake overheats, efficiency is so
reduced that fade occurs. Since the opposite brake
unit is still functioning normally, its braking effect is
magnified. This causes pull to switch direction in
favor of the normally functioning brake unit.
An additional point when diagnosing a change in
pull condition concerns brake cool down. Remember
that pull will return to the original direction, if the
dragging brake unit is al

DIAGNOSIS AND TESTING - MASTER
CYLINDER/POWER BOOSTER
(1) Start engine and check booster vacuum hose
connections. A hissing noise indicates vacuum leak.
Correct any vacuum leak before proceeding.
(2) Stop engine and shift transmission into Neutral.
(3) Pump brake pedal until all vacuum reserve in
booster is depleted.
(4) Press and hold brake pedal under light foot
pressure. The pedal should hold firm, if the pedal
falls away master cylinder is faulty (internal leakage).
(5) Start engine and note pedal action. It should
fall away slightly under light foot pressure then hold
firm. If no pedal action is discernible, power booster,
vacuum supply, or vacuum check valve is faulty. Proceed
to the POWER BOOSTER VACUUM TEST.
(6) If the POWER BOOSTER VACUUM TEST
passes, rebuild booster vacuum reserve as follows:
Release brake pedal. Increase engine speed to 1500
rpm, close the throttle and immediately turn off ignition
to stop engine.
(7) Wait a minimum of 90 seconds and try brake
action again. Booster should provide two or more vacuum
assisted pedal applications. If vacuum assist is
not provided, booster is faulty.

POWER BOOSTER CHECK VALVE TEST
(1) Disconnect vacuum hose from check valve.
(2) Remove check valve and valve seal from
booster.
(3) Use a hand operated vacuum pump for test.
(4) Apply 15-20 inches vacuum at large end of
check valve (Fig. 39).
(5) Vacuum should hold steady. If gauge on pump
indicates vacuum loss, check valve is faulty and
should be replaced.

This is the second time this has happened... Jeep sits in the rain untouched for a few hours, I go to drive it, and the braking on the Liberty sucks. It feels like the front brakes are simply not working...

After a few hard stops (not just regular stopping), it feels like the front right brake starts to work (pulls to the right) , and after a few more stops, braking is back to normal.

It was scarey as hell the first time it happened.... Anyone have any ideas?

I don't mean to hijack but does anyone know the size of the bolt in the middle of the rotor on the front?

I'll be replacing both of my front brake calipers this weekend...

So that was braking with 1 caliper... I bet your Liberty is so much easier to slow down now.

I know this is about the third "funny you mention this" response, buuut

Almost the same thing here, but I get a terrible rough grinding from the front left rotor, like theres no pad at all, but it only happens every now and then. I would think it would be all the time or never, but it's strange. Particularly noticeable in the rain.

Author:	BeepBeepJeepJeep [ Fri Mar 07, 2008 6:46 pm ]
Post subject:	My front brakes are worrying me...
This is the second time this has happened... Jeep sits in the rain untouched for a few hours, I go to drive it, and the braking on the Liberty sucks. It feels like the front brakes are simply not working... After a few hard stops (not just regular stopping), it feels like the front right brake starts to work (pulls to the right) , and after a few more stops, braking is back to normal. It was scarey as hell the first time it happened.... Anyone have any ideas?

Author:	tjkj2002 [ Fri Mar 07, 2008 7:02 pm ]
Post subject:
have you ever flushed your brake fluid? I would,and do a really good brake bleeding. Quote: HARD PEDAL OR HIGH PEDAL EFFORT A hard pedal or high pedal effort may be due to lining that is water soaked, contaminated, glazed, or badly worn. The power booster or check valve could also be faulty. Quote: BRAKE PULL Front brake pull condition could result from: † Contaminated lining in one caliper † Seized caliper piston † Binding caliper † Loose caliper † Rusty caliper slide surfaces † Improper brake shoes † Damaged rotor A worn, damaged wheel bearing or suspension component are further causes of pull. A damaged front tire (bruised, ply separation) can also cause pull. A common and frequently misdiagnosed pull condition is where direction of pull changes after a few stops. The cause is a combination of brake drag followed by fade at one of the brake units. As the dragging brake overheats, efficiency is so reduced that fade occurs. Since the opposite brake unit is still functioning normally, its braking effect is magnified. This causes pull to switch direction in favor of the normally functioning brake unit. An additional point when diagnosing a change in pull condition concerns brake cool down. Remember that pull will return to the original direction, if the dragging brake unit is al Quote: DIAGNOSIS AND TESTING - MASTER CYLINDER/POWER BOOSTER (1) Start engine and check booster vacuum hose connections. A hissing noise indicates vacuum leak. Correct any vacuum leak before proceeding. (2) Stop engine and shift transmission into Neutral. (3) Pump brake pedal until all vacuum reserve in booster is depleted. (4) Press and hold brake pedal under light foot pressure. The pedal should hold firm, if the pedal falls away master cylinder is faulty (internal leakage). (5) Start engine and note pedal action. It should fall away slightly under light foot pressure then hold firm. If no pedal action is discernible, power booster, vacuum supply, or vacuum check valve is faulty. Proceed to the POWER BOOSTER VACUUM TEST. (6) If the POWER BOOSTER VACUUM TEST passes, rebuild booster vacuum reserve as follows: Release brake pedal. Increase engine speed to 1500 rpm, close the throttle and immediately turn off ignition to stop engine. (7) Wait a minimum of 90 seconds and try brake action again. Booster should provide two or more vacuum assisted pedal applications. If vacuum assist is not provided, booster is faulty. Quote: POWER BOOSTER CHECK VALVE TEST (1) Disconnect vacuum hose from check valve. (2) Remove check valve and valve seal from booster. (3) Use a hand operated vacuum pump for test. (4) Apply 15-20 inches vacuum at large end of check valve (Fig. 39). (5) Vacuum should hold steady. If gauge on pump indicates vacuum loss, check valve is faulty and should be replaced.

Author:	BeepBeepJeepJeep [ Fri Mar 07, 2008 7:13 pm ]
Post subject:
It only does it in the rain though... So I'll check out the pads first like the second quoted segment says...

Author:	Prometheus Xray [ Fri Mar 07, 2008 7:44 pm ]
Post subject:
thats funny that u mention that. the other day some guy pulled a wicked drift through a red light while it was raining and i locked them up and i felt the wheel rip right on me and i had to really flex to keep it from whipping off the road. after that it was fine though. my breaks are strarting to screech though so i may need to replace them

Author:	Jeepjeepster [ Fri Mar 07, 2008 10:13 pm ]
Post subject:
You just had a wheel lock-up Xray. Very normal if youre not use to driving with-out ABS or just dont care. I had a wheel lock-up when one of those people decided they felt the need to suddenly turn off with-out a signal or anything today in the rain. Wasnt really a panic situation, I figured it would lock-up since I do it all the time. Best way to learn is to go out and play.

LOST JEEPS http://www.lostjeeps.com/forum/phpBB3/

My front brakes are worrying me... http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=1&t=30263	Page 1 of 1

Author:	sleeve84028 [ Sat Mar 08, 2008 10:43 am ]
Post subject:
brake fluid absorbs water and causes poor braking performance.

Author:	Dje Ryu [ Sat Mar 08, 2008 1:35 pm ]
Post subject:
Whenever I know my brake pads are wet, I just lightly press on the brake while I'm driving, just enough that I feel them start to grab. An old truck driver trick for drying wet brake pads.

Author:	Prospect62 [ Sun Mar 09, 2008 6:11 pm ]
Post subject:	Re: My front brakes are worrying me...
BeepBeepJeepJeep wrote: This is the second time this has happened... Jeep sits in the rain untouched for a few hours, I go to drive it, and the braking on the Liberty sucks. It feels like the front brakes are simply not working... After a few hard stops (not just regular stopping), it feels like the front right brake starts to work (pulls to the right) , and after a few more stops, braking is back to normal. It was scarey as hell the first time it happened.... Anyone have any ideas? It's funny you should bring this up, mine just started to do this the other day, too. I just replaced my front brakes and rotors (and I did a quality job). I'm going to blame the intermittent pull on a bad passenger wheel bearing or the rest of my suspension that sounds and feels like it's made out of legos.

Author:	gone_jeepin [ Mon Mar 10, 2008 1:54 pm ]
Post subject:
I don't mean to hijack but does anyone know the size of the bolt in the middle of the rotor on the front?

Author:	JIMMY JEEP [ Mon Mar 10, 2008 2:23 pm ]
Post subject:
I'll put money that your dust seal has perforated and has let moisture into the caliper piston causing it to stick and pull you to one side,it will only get worse you need to either fit a new caliper or fit a piston repair kit consisting of a new piston ,retaining clip and dust seal.You can only use the kit if the bore of the caliper isnt to badly corroded ,if it is then fit a new caliper.After a journey were the car feels like its been pulling to one side place your hand carefully on the wheel and compare heat differences side to side ,if one side is hot it will confirm a sticking caliper.

Author:	tjkj2002 [ Mon Mar 10, 2008 2:31 pm ]
Post subject:
gone_jeepin wrote: I don't mean to hijack but does anyone know the size of the bolt in the middle of the rotor on the front? If your reffering to the CV nut,it's 35mm.

Author:	BeepBeepJeepJeep [ Mon Mar 10, 2008 4:38 pm ]
Post subject:
I'll be replacing both of my front brake calipers this weekend...

Author:	sleeve84028 [ Tue Mar 11, 2008 8:04 am ]
Post subject:
So that was braking with 1 caliper... I bet your Liberty is so much easier to slow down now.

Author:	xturboexpress [ Tue Mar 11, 2008 10:58 am ]
Post subject:
I know this is about the third "funny you mention this" response, buuut Almost the same thing here, but I get a terrible rough grinding from the front left rotor, like theres no pad at all, but it only happens every now and then. I would think it would be all the time or never, but it's strange. Particularly noticeable in the rain.

Page 1 of 1	All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/

Author:	BeepBeepJeepJeep [ Tue Mar 11, 2008 11:04 am ]
Post subject:
sleeve84028 wrote: So that was braking with 1 caliper... I bet your Liberty is so much easier to slow down now. Hell yeah!

Author:	JIMMY JEEP [ Tue Mar 11, 2008 3:27 pm ]
Post subject:
I put money on it, cash or cheque please.lol

Author:	Prospect62 [ Thu Mar 13, 2008 11:04 am ]
Post subject:
xturboexpress wrote: I know this is about the third "funny you mention this" response, buuut Almost the same thing here, but I get a terrible rough grinding from the front left rotor, like theres no pad at all, but it only happens every now and then. I would think it would be all the time or never, but it's strange. Particularly noticeable in the rain. Check the pads and rotors to make sure they aren't down to metal on metal. If not, could be the wheel bearing. That's what mine was.