Click on pictures for a larger, detailed view
Recently after noticing a sudden surge in ABS pump replacements I decided to investigate what was going on, age and mileage seems to play a role here but something wasn't right and here's my findings detailed below, bare in mind different operating conditions throughout the world vary.....
Fault 1: Dark brownish clear brake fluid means its old and fluid has not been changed in a long long time.
Replace fluid and bleed complete braking system, requires around 4 liters of DOT 4 brake fluid
Fault 2: Dark brown but not clear indicates dirt within fluid and urgent replacement of fluid is needed.
Fault 3: Black fluid, probably never changed since it was sold off the show room floor, lets hope the internals
of the brake modulator are tougher than they look, they are not repairable for liability reasons and parts are not available.
Brake fluid must be replaced every two years as a routine, more often at least once a year if used in severe conditions.
Brake fluid is designed to prevent boiling, prevent rust and it aids in lubrication of moving parts..... but not for long as the fluid breaks down.
The above was removed from a 1999 brake modulator.
Concerned, then the safest bet would be to replace.
Use a good quality DOT 4 brake fluid
More details with screen filter removed
The below picture is typical of bad brake fluid from these vehicles and its way to regular that I see this
This is the filler neck, a clear indication that the reservoir must be replaced
Recently I have been contacted with a clean out process I have tried, although it works well to some degree depending on age and state I still prefer to replace with new. So much so that I have replaced mine with new, no point in suggesting something if I don't do it myself for a reason.
ABS Total strip down to follow showing all the bits and bobs for all to see (In progress)
First up to this addition on new info is the dreaded ABS pump relay, as you will see from the pictures the contact pads are burnt, these relay caused a perfectly good ABS pump to burn out, so whats going on....
Well for starters the ABS pump demands rougly around 70amps at start up, when the pads make contact there is whats knowing are arcing on the contact pads, as you can see there are two but one pad will always make contact first, this is the start to a fusing relay, one that will jam and make the ABS pump run continously and burn out.
So whats the solution, at present on the work bench I run a few cycles with the same type of relay and load, the relay cover has been removed so I can see in real time whats going on and its like lightening on those pads.
I have from the begining believed that a capacitor or lets call it a condensor for the guys who are familiar with "Points and condensors" (on non electronic distrubutors) to be the solution and it seems to be working to a large degree but final tweaking to the correct cap in near, the final leg of this minor but important mod is a few days away with easy instructions on how to install the cap.
In the meantime......
Then some brake modulator pics (to be edited)