ABS plumbing

[AZPete]

Junty, I've got a lot to do before I can test the ABS - shifter, E-brake, radiator, wiring (Yikes!), buy wheels & tires, add fluids . . . and?
I think Erik's is the only 818 on the road legally and it's too cold for him to do much now. Stay tuned.
Happy New Year, Junty.

[Goldwing]

Hey guys, just wondering if any of you had any further thoughts on brake line routing after furthering your builds. Any conflicts with panels, etc? I'm getting ready to run mine, with ABS. I have the extra prop. valve, and lines/ fittings just need to figure out which port goes where leaving the ABS unit. Did some searching, but didn't try the obvious to check the actual unit for labeling, but that just seems way too convenient to be reality, lol. It's just buried a little. Skipping the backordered fuel stuff put me here suddenly. Doing a little homework to refresh the plan tonight.

[Goldwing]

Curious, after I got the little one to bed, I dug out the ABS unit. What a seriously pleasant surprise. Clearly marked brake line ports on the ABS unit. The little things, right?, too used to little challenges creeping up everywhere, lol.

[billjr212]

Prepare for the stupid question, only because I haven't seen it directly addressed:

Those going with ABS - are you keeping the brake booster, or are we thinking the ABS will work with manual brakes?

I don't see why it would matter, but at the same time, ABS didn't really exist before power brakes, so short of me starting to tear into my donor and tracing lines (which will happen soon enough), my brain is probably just overthinking this.

Thanks!

[Goldwing]

Prepare for the stupid question, only because I haven't seen it directly addressed:

Those going with ABS - are you keeping the brake booster, or are we thinking the ABS will work with manual brakes?

I don't see why it would matter, but at the same time, ABS didn't really exist before power brakes, so short of me starting to tear into my donor and tracing lines (which will happen soon enough), my brain is probably just overthinking this.

Thanks!

No worries, I asked it a while ago too, and so have many others, lol. ABS works independent from the booster, and thus not a concern. The booster just uses the difference between vacuum and atmospheric pressure to help you push harder on the pushrod in the master cylinder, and shares no hydraulic or electrical connection to the ABS. With the lighter car, and adjusted brake master pushrod mounting point, we can create enough pressure to lock the wheels with our lead feet. The ABS takes over from there. To keep ABS, You'll just need an extra wilwood proportioning valve (just order the same model number that shows up in your kit, it's on Amazon even), more brake lines to recreate what was in the donor, 10mm brake line nuts, and a flaring tool. Or buy more identical lines and adapters. I think I only needed a 25' coil to supplement the supplied lines and run everything.

[billjr212]

excellent. thank you. i'm still at the tearing down and parting out of the donor phase and I just don't want to kick myself later for getting rid of something I need. definitely will reference back here when it comes time to run lines.

[Goldwing]

As a point, save the clevis clamp off the booster's pushrod. It will attach to an FFR provided pushrod to hold it to the brake pedal.

[AZPete]

Reviving this old thread. Way back in 2014 I installed proportioning valves on both of the front brake lines, between the ABS module and the front calipers. My brakes work well but was I over-thinking it? I recall other guys have installed the donor ABS without any prop valves, so can anyone report if the ABS works well without prop valves?

[ben1272]

Kurk818 plumbed his as per the labeling on the ABS module and did not use proportioning valves and I believe he has had promising results. I will be following his path.

[Hindsight]

I did mine with one prop valve for each front caliper. Seems to be working but I've only had a split second time where it kicked in and that was while braking hard and going over a pot-hole. I still need to do a full ABS check to test it but so far so good.

[turbomacncheese]

Thanks for resurrecting this thread. Good read for me. And huge thanks to wleehendrick for all that explaining. Perfect.

[DMC7492]

This has been posted some wher else in the forum.
I'm using Wilwood brakes for 2005WRX. Factory ABS NO proportioning valves. The system works very well in go cart mode. Tested at 25, 45, and 60 mph by putting the right wheels in the grass and left wheels on asphalt at 25 it stopped straight and the valves were buzzing, then at 45 on asphalt left wheels in the winter pea gravel, then at 60 same test! I was very happy with the performance. I'm working on the body now so no more testing was done since spring. Have fun!! Don