So the car I bought back in August has serious gunk/gel throughout the whole brake system. I've already... * replaced: reservoir, master cylinder, clutch master * cleaned: all three reservoir hoses * bought kits for: rebuilding all four calipers, replacing hard lines * bought, but not received: four new hoses This conspicuously leaves the ABS module. Based on what I've seen elsewhere, it's gotta be full of gelled awfulness. Can I take it apart and rebuild it? Or at least inspect the interior? I took the solenoids and electronics off mine, but beyond that, not sure what to do next. I really don't want to pay thousands of dollars for a new one, or buy a used one (because, like mine, I can't verify that it's clean inside). So hopefully I can rebuild it. Advice greatly appreciated!
I had exactly the same problem all Gunked up. I changed all the seals, break lines and still did not cure the problem. I thought about taking the ABS unit apart but was advised just to replace it. I purchased a second hand unit that was not cheap and this cure the problem. It would be very interesting to find out if you can refurbish the ABS unit.
What was the "problem" you were trying to fix? I've not even taken my car over 10 mph yet - too scared of brake failure.
Don't get ahead of yourself. Install new lines, flush the fluid, and (safely) take it for a test drive. ABS module may be fine.
Brake lines aren't like oil or gas lines. There's no fluid pumping through them. It's a hydraulic system.
As the pads wear, the pistons in the calipers have to come out further to maintain friction surface contact. This means a need for more brake fluid in the calipers, which has to flow from the reservoir, through the ABS module, to get there. It's not fast, obviously, unless you spend some time at the track, but it does happen. As for the module itself, I understand what abs does, but not exactly how it does it. I know that six solenoids operate six valves (whose outer bodies have two different types of shape), which must reduce pressure to the calipers, and there's also a pump. Some sources refer to a "return line" indicating that, like with oil, there is some circulation. I understand pre-abs brakes fine, but I really feel pretty ignorant on the topic of abs. So I bought a used Miata abs unit on eBay. I plan to tear it apart to understand what exactly is going on, and if there's a non-destructive way to remove the valves for inspection/cleaning. Finally, I asked a few days ago how the secondary (left/front on US cars) tank of the reservoir gets filled, since it doesn't seem to be connected to the primary. No one answered, but my suspicion is that fluid comes back up through the master cylinder (and abs unit) to get in there. (Obviously this would require an air vent of some kind in the secondary tank.) Is the front pressure line of the MC a "return line?" This would again mean significant movement of fluid through the abs module, wouldn't it?
I would flush the system then take it out on a section of road with poor traction (wet, sand, etc) and brake hard enough to activate the ABS system. Do this several time. If there is gunk in the ABS system I would think it would flush it out. Then you can flush the brake again to clear everything. Worth a shot. IMO.
The two sections of the reservoir are connected by overflow (as you fill the reservoir) over the middle divider. The divider does not go all the way up to the "roof" but there is a gap (a "spillway") to enable filling of both chambers. The divider is necessary so that, if one circuit fails and its fluid leaks out, the other circuit will still have fluid in the reservoir up to the spillway. Something like on this drawing except that the cap of your reservoir is not in the centre so you cannot see the top line of the divider. Image Unavailable, Please Login
I was bleeding the system, as the ABS was not working correctly at the time, It took many attempts to bleed the system, specialist told me to replace ABS unit.
This is a stupid question: everything you have talked about is the fluid/mechanical side of the brake system. I'm assuming the vastly complex electrical ABS components are working correctly? Is your ABS warning light on on the dash? That would suggest electrical gremlins. If it isn't, did you check to be sure no one was sleazy enough to remove the bulb from the warning light? The light should be on when you first start the car and go out after a few seconds. There are so many ways the electronics can fail i would hate for you to cough up the eye watering price of a new ABS/master cylinder unit and find out that it wasn't at fault after all. If in doubt search YouTube for "348 ABS" and you should find some videos going through the ABS electronics. Sent from my SM-G975U using Tapatalk
