96' Discovery Braking Problem
Thread Starter
|
6th Gear
Joined: Dec 2011
Posts: 6
Likes: 0
96' Discovery Braking Problem
I've had the following ongoing problem.
When braking while driving very slowly, the brakes seem to "let go" while the pedal travels almost to the floor where it becomes hard but unresponsive. It's accompanied by a mechanical kind of scraping noise which seems to come from the front of the vehicle.
This as mentioned, only occurs when braking lightly while travelling slowly and usually downhill (For example, down a steep driveway ) although it has happened on the flat also when braking slowly.
The brake pedal is always more than halfway to the floor when depressed even on the highway and despite my bleeding them (several times) which corrects the pedal position for about a week, it gradually gets lower and lower until it's back to half travel distance to the floor.
There are no obvious fluid leaks and it's not using any fluid however, a couple of pumps does improve the pedal position slightly but the main "Letting Go" issue remains.
Any ideas much will be most appreciated.
Kellio
When braking while driving very slowly, the brakes seem to "let go" while the pedal travels almost to the floor where it becomes hard but unresponsive. It's accompanied by a mechanical kind of scraping noise which seems to come from the front of the vehicle.
This as mentioned, only occurs when braking lightly while travelling slowly and usually downhill (For example, down a steep driveway ) although it has happened on the flat also when braking slowly.
The brake pedal is always more than halfway to the floor when depressed even on the highway and despite my bleeding them (several times) which corrects the pedal position for about a week, it gradually gets lower and lower until it's back to half travel distance to the floor.
There are no obvious fluid leaks and it's not using any fluid however, a couple of pumps does improve the pedal position slightly but the main "Letting Go" issue remains.
Any ideas much will be most appreciated.
Kellio
Super Moderator
Joined: Jan 2011
Posts: 16,322
Likes: 88
From: Savannah Georgia
re: it gradually gets lower and lower until it's back to half travel distance to the floor
IMHO then you do have a leak, but just not too obvious. If wheels off insection reveals nothing, and flush with 2 quarts of DOT 4 fluid and re-bleed does not do it, then you could be left with a master cylinder issue. Depressed slightly you get to the corrosion / ragged seal spot and leak (perhaps just internal), depress firmly and you move beyond it. See attached pages from RAVE, you should have your own copy of this shop manual (free link below) before starting this type of repair.
This would be a good time to exercise extreme caution, and utilize the back up vehicle. At 4464 pounds, plus gas and gear and people, dragging your foot isn't an option and the parking brake may not be up to the task in many situations. A Dodge minivan is a thousand pounds less...
IMHO then you do have a leak, but just not too obvious. If wheels off insection reveals nothing, and flush with 2 quarts of DOT 4 fluid and re-bleed does not do it, then you could be left with a master cylinder issue. Depressed slightly you get to the corrosion / ragged seal spot and leak (perhaps just internal), depress firmly and you move beyond it. See attached pages from RAVE, you should have your own copy of this shop manual (free link below) before starting this type of repair.
This would be a good time to exercise extreme caution, and utilize the back up vehicle. At 4464 pounds, plus gas and gear and people, dragging your foot isn't an option and the parking brake may not be up to the task in many situations. A Dodge minivan is a thousand pounds less...
Thread Starter
|
6th Gear
Joined: Dec 2011
Posts: 6
Likes: 0
Thanks for the advice. Who is A.B.? Do they have a website?
Rock Crawling
Joined: Feb 2009
Posts: 294
Likes: 0
From: Ringgold,ga
I've had the following ongoing problem.
When braking while driving very slowly, the brakes seem to "let go" while the pedal travels almost to the floor where it becomes hard but unresponsive. It's accompanied by a mechanical kind of scraping noise which seems to come from the front of the vehicle.
This as mentioned, only occurs when braking lightly while travelling slowly and usually downhill (For example, down a steep driveway ) although it has happened on the flat also when braking slowly.
The brake pedal is always more than halfway to the floor when depressed even on the highway and despite my bleeding them (several times) which corrects the pedal position for about a week, it gradually gets lower and lower until it's back to half travel distance to the floor.
There are no obvious fluid leaks and it's not using any fluid however, a couple of pumps does improve the pedal position slightly but the main "Letting Go" issue remains.
Any ideas much will be most appreciated.
Kellio
When braking while driving very slowly, the brakes seem to "let go" while the pedal travels almost to the floor where it becomes hard but unresponsive. It's accompanied by a mechanical kind of scraping noise which seems to come from the front of the vehicle.
This as mentioned, only occurs when braking lightly while travelling slowly and usually downhill (For example, down a steep driveway ) although it has happened on the flat also when braking slowly.
The brake pedal is always more than halfway to the floor when depressed even on the highway and despite my bleeding them (several times) which corrects the pedal position for about a week, it gradually gets lower and lower until it's back to half travel distance to the floor.
There are no obvious fluid leaks and it's not using any fluid however, a couple of pumps does improve the pedal position slightly but the main "Letting Go" issue remains.
Any ideas much will be most appreciated.
Kellio
Man where was I when this was posted?
It is his ABS pump acting up, he needs to remove the ABS pump fuse from under the hood.
The ABS pump acts up because of 2 things, a faulty ABS sensor or gunk build up inside the ABS pump itself.
Land Rover says to flush the brake fluid every 24 months no matter the miles, in fact almost all car companies recommend this now.
This is because gunk builds up inside the ABS pump and block the valves which regulate the brake pressure to each wheel.
Fresh fluid in the system will prevent this from happening.
Land Rover says to flush the brake fluid every 24 months no matter the miles, in fact almost all car companies recommend this now.
This is because gunk builds up inside the ABS pump and block the valves which regulate the brake pressure to each wheel.
Fresh fluid in the system will prevent this from happening.
The ABS pump acts up because of 2 things, a faulty ABS sensor or gunk build up inside the ABS pump itself.
Land Rover says to flush the brake fluid every 24 months no matter the miles, in fact almost all car companies recommend this now.
This is because gunk builds up inside the ABS pump and block the valves which regulate the brake pressure to each wheel.
Fresh fluid in the system will prevent this from happening.
Land Rover says to flush the brake fluid every 24 months no matter the miles, in fact almost all car companies recommend this now.
This is because gunk builds up inside the ABS pump and block the valves which regulate the brake pressure to each wheel.
Fresh fluid in the system will prevent this from happening.
Thread Starter
|
6th Gear
Joined: Dec 2011
Posts: 6
Likes: 0
Replaced master cylinder to no avail.
On the recommendations posted by members I replaced the master cylinder and bled the system.
All went well for about 2 days but gradually deteriorated to the same condition as before.
Back to square one.
All went well for about 2 days but gradually deteriorated to the same condition as before.
Back to square one.
