QUESTION
I have just fitted a replacement ABS brake switch supplied by Lotus Marques but the "ANTI LOCK" light comes on.
The pump leaps into action whenever I waft my foot near the pedal.
The brake feel is still very poor and it seems like the switch wasn't the only problem.
Do you have any advice on what I should tackle next?
Should I get a new pump or fit a new accumulator (I only replaced the accumulator a couple of years ago)?
Do I bleed the system properly and hope that will sort it out?
I'd be really grateful for your advice. I'm beginning to despair of ever having working brakes again.
B.A. - UK
ANSWER
From what you describe it sounds as if you have more than one problem.
The fact that the ANTI LOCK dashboard warning light comes is symptomatic of a low overall system pressure.
The quickest and most accurate way to diagnose the ABS hydraulic system (and its associated components) is to install a simple test rig that incorporates a gauge in series with the accumulator.
You can purchase the test rig as shown here in the tool section on the Lotus Marques web site.
From experience, it would be wise to bleed the high pressure hydraulic system at the solenoid manifold to disperse any air introduced whilst fitting a new switch assembly.
The ABS brake bleeding procedure can be found here on the Lotus Marques web site
From what I understand from your comments, the pump appears to run every time you operate the brake pedal?
If the high pressure system is operating correctly then the pump should only run every 3 or 5 brake pedal applications.
However, if the pump runs on every brake pedal application, this is indicative a low pressure accumulator (or a faulty high pressure switch or a faulty high pressure pump relief valve which in this case is unlikely)
Copyright © 2012 Lotus Marques
I have just fitted a replacement ABS brake switch supplied by Lotus Marques but the "ANTI LOCK" light comes on.
The pump leaps into action whenever I waft my foot near the pedal.
The brake feel is still very poor and it seems like the switch wasn't the only problem.
Do you have any advice on what I should tackle next?
Should I get a new pump or fit a new accumulator (I only replaced the accumulator a couple of years ago)?
Do I bleed the system properly and hope that will sort it out?
I'd be really grateful for your advice. I'm beginning to despair of ever having working brakes again.
B.A. - UK
ANSWER
From what you describe it sounds as if you have more than one problem.
The fact that the ANTI LOCK dashboard warning light comes is symptomatic of a low overall system pressure.
The quickest and most accurate way to diagnose the ABS hydraulic system (and its associated components) is to install a simple test rig that incorporates a gauge in series with the accumulator.
You can purchase the test rig as shown here in the tool section on the Lotus Marques web site.
From experience, it would be wise to bleed the high pressure hydraulic system at the solenoid manifold to disperse any air introduced whilst fitting a new switch assembly.
The ABS brake bleeding procedure can be found here on the Lotus Marques web site
From what I understand from your comments, the pump appears to run every time you operate the brake pedal?
If the high pressure system is operating correctly then the pump should only run every 3 or 5 brake pedal applications.
However, if the pump runs on every brake pedal application, this is indicative a low pressure accumulator (or a faulty high pressure switch or a faulty high pressure pump relief valve which in this case is unlikely)
Copyright © 2012 Lotus Marques