Land Rover help!

[Trent Closson]

I have an issue that so far, 3 mechanics can't narrow down and I need input from Landy drivers. I got ball joints replaced awhile back and ever since my ABS and TC lights are on. My brakes won't hold pressure when the rig is setting over 12 hours but there isn't a leak anywhere either. When driving the brakes are fine. Any thoughts?
Thanks!

 

[Dilldog]

When you say your brakes won't hold pressure after the rig sits do you mean the first brake application the pedal goes to the floor? My guess is they removed brake lines to get the ball joints replaced. Once air is in an ABS system it can do so very wacky stuff, this would also explain the warning lights. Probably needs the brakes bled. Most newer rigs require a high level scan tool access to engage the ABS system motor to power bleed the system. If air is in the ABS module itself, that will be the only way to get it out.

 

[Trent Closson]

When you say your brakes won't hold pressure after the rig sits do you mean the first brake application the pedal goes to the floor? My guess is they removed brake lines to get the ball joints replaced. Once air is in an ABS system it can do so very wacky stuff, this would also explain the warning lights. Probably needs the brakes bled. Most newer rigs require a high level scan tool access to engage the ABS system motor to power bleed the system. If air is in the ABS module itself, that will be the only way to get it out.

Yes after it's been sitting for some time the pedal goes to the floor. The ABS accumulator will still build pressure but it also looses pressure as I said. I haven't tried bleeding the brakes since it's a complicated process with this vehicle and I'm timid to wreck something even worse. I'll do studying and see if I can bleed them and fox the issue.

 

[Dilldog]

Yes after it's been sitting for some time the pedal goes to the floor. The ABS accumulator will still build pressure but it also looses pressure as I said. I haven't tried bleeding the brakes since it's a complicated process with this vehicle and I'm timid to wreck something even worse. I'll do studying and see if I can bleed them and fox the issue.

Like I said above, most ABS systems require a scan tool with high level permissions to bleed the brakes fully. I would try the old school method, or grab a tool to vacuum bleed them (hand vacuum pumps can be had for $40, even my Blue Point kit only cost $150). But just don't get discouraged if that doesn't fix it. You might have to swing it by a brake shop that can work on Land Rover ABS systems, or a dealer.

 

[ChambersFamily]

I 2nd air in the system. I've never had a issue doing it the old school way even with newer setups...

 

[Dilldog]

I 2nd air in the system. I've never had a issue doing it the old school way even with newer setups...

I've bled ABS systems without engaging the ABS motor as well tons of times. I just brought that up because if air has migrated into the valving for the ABS then just using the old school methods probably won't work.

 

[Shakes355]

Without being familiar with your exact setup and what codes are actually being thrown by the module, it's kind of a shot in the dark. But any time the system is opened for any reason, it should be bled thoroughly. Especially on abs equipped vehicles. Air will slowly rise on it's own through the system from the calipers to the master cylinder. It sounds as if that's the concern. You cant compress liquids but you can compress air (gas) so if theres a pocket in the master, the pedal will go to the floor the first couple strokes until fluid from the res displaces it. Air in the module can also throw codes due to the pressure sensors reading low.

Doing it the old fashioned way (with another person pumping the pedal) will eliminate the air 90% of the time. You may just end up running through a couple pints of fluid to work all of it out. Sometimes it's difficult to get air out of the abs valve body. In which case, you can bleed like you normally would (with a buddy) but instead of just cracking the bleeder on the caliper, you also crack the input/output lines on the abs module in succession.

Even then, some air may remain and give you a soft pedal. At that point, you need to clear the codes and ensure none return due to other problems (like a damaged wheel speed sensor). Find some sand or gravel and force an abs skid (panic stop on the loose surface to actuate the pump).

The codes need to be cleared because detected faults can lockout abs function. When the pump runs with the high pedal pressure you exert, it will force out air remaining in the module. Then simply bleed all 4 wheels again at the calipers.

 

[Trent Closson]

Thanks everyone for the help!! I'm going to replace brake pads next weekend and bleed the brakes after. Hopefully that solves the issue! The fluid does rise in the master cylinder after sitting so I'm glad you mentioned that. I also thought about getting the ABS sensors checked but let's take a step at a time!

 

[RickR]

Bleed your breaks.

 

[Dilldog]

Without being familiar with your exact setup and what codes are actually being thrown by the module, it's kind of a shot in the dark. But any time the system is opened for any reason, it should be bled thoroughly. Especially on abs equipped vehicles. Air will slowly rise on it's own through the system from the calipers to the master cylinder. It sounds as if that's the concern. You cant compress liquids but you can compress air (gas) so if theres a pocket in the master, the pedal will go to the floor the first couple strokes until fluid from the res displaces it. Air in the module can also throw codes due to the pressure sensors reading low.

Doing it the old fashioned way (with another person pumping the pedal) will eliminate the air 90% of the time. You may just end up running through a couple pints of fluid to work all of it out. Sometimes it's difficult to get air out of the abs valve body. In which case, you can bleed like you normally would (with a buddy) but instead of just cracking the bleeder on the caliper, you also crack the input/output lines on the abs module in succession.

Even then, some air may remain and give you a soft pedal. At that point, you need to clear the codes and ensure none return due to other problems (like a damaged wheel speed sensor). Find some sand or gravel and force an abs skid (panic stop on the loose surface to actuate the pump).

The codes need to be cleared because detected faults can lockout abs function. When the pump runs with the high pedal pressure you exert, it will force out air remaining in the module. Then simply bleed all 4 wheels again at the calipers.

I didn't think of getting of the ABS to engage to get the air out of the module, good call.

 

[Davidmoate]

Did you get anywhere with your Landy brake problems?

 

[Trent Closson]

Did you get anywhere with your Landy brake problems?

I went to do brake work and found my right rear caliper was seized. I ordered calipers and the whole 9 yards like I should've.. should be here today and hopefully that will solve the issue

 

[Trent Closson]

Alright I ended up replacing both brake calipers and pads in the rear. Bled the brakes and so far the brakes are stiff again but my ABS and TC lights are still on. I didn't fully expect to gain these back but I'm still curious about why they are reading error. Any ideas?

 

[Dilldog]

Alright I ended up replacing both brake calipers and pads in the rear. Bled the brakes and so far the brakes are stiff again but my ABS and TC lights are still on. I didn't fully expect to gain these back but I'm still curious about why they are reading error. Any ideas?

Try running down to a parts store that will let you use a scan tool. Clear the codes and see if they come back.