ABS Pump Bleeder Nipple?

**golgo13** · 01-22-2018, 03:54 PM

So, I'm looking into trying to get all the air out of my brake system and I believe that I have air trapped in the ABS module.

Before anyone asks, I've already bled 1L of fluid through the system using the 2 person method including cycling the ABS intake/exhaust solenoids with the pump via INPA. My next step will probably be to use Rheingold and try the ABS bleed sequence included with that dealership software. While I'm waiting to get that set-up, I wanted to see if anyone on the forums has ever had any success attaching a line to the nipple on the pump and then bleeding from there with the pump actuating.
It's almost impossible to access this nipple with the M/C, reservoir and the fuse box in the way, but I'm sure someone has tried this at least once?

I'm talking about this:

Usually it has a rubber cap on it like a brake caliper bleeder:

**RRSperry** · 01-24-2018, 09:06 AM

Wow, you got me there. If you've used the Gt1 or INPA to cycle the abs while pressure bleeding and it still isn't working, I'd suspect the ABS module.

**golgo13** · 01-24-2018, 12:20 PM

Originally Posted by RRSperry

Wow, you got me there. If you've used the Gt1 or INPA to cycle the abs while pressure bleeding and it still isn't working, I'd suspect the ABS module.

I don't know the proper sequence with INPA, but I've been reading that there might be something under the "special tests" menu? I'll have to try that next, but before I was doing things one step at a time:

Pressurize brake system
Open bleeder
Activate Intake Solenoid
Activate Pump
Activate Exhaust Solenoid
Close bleeder

I have no idea if this is correct or what, since info is scarce, outdated or lost to the sands of internet time.

**AJLM34A** · 01-24-2018, 01:22 PM

When I rebuilt all four of my calipers and used a Motive pressure bleeder, I had a soft peddle after bleeding. I just opened each bleeder 1 at a time for about 30 seconds, hooked the pressure bleeder back up and had a firm peddle without cycling the ABS pump.

**Mless5** · 01-28-2018, 09:35 PM

Please, post back your findings once you get it resolved. Thanks.

**tripitz** · 01-30-2018, 07:49 AM

After a full everything swap from a wrecked M3 to a 325i chassis, including removing and repairing damaged hardline in the donor car, I'm also dealing with this issue. I put about 1.5 liters through the system and the pedal feel is anything but good. I spoke to my local race shop and they said to keep bleeding; sometimes it will take quite a bit more than 1-1.5 liters to get it right. I would recommend buying some cheap fluid and trying again. That is my plan for this weekend.

**TostitoBandito** · 01-30-2018, 10:19 AM

When I want to be thorough I'll do a standard bleed, go out on a drive and engage ABS a couple times, and then another quick bleed at all four corners to get any air that's come out of the ABS.

**golgo13** · 01-31-2018, 04:07 PM

Cleared some room to try and bleed the ABS pump and then working with tlrid3r to install a hard line with a bleeder off of the pump. Stay tuned for that.

**LockDots** · 02-01-2018, 12:56 PM

very cool. Can't wait to see how this turns out!

**golgo13** · 02-01-2018, 01:09 PM

The challenge here is to get the thread pitch and depth of the bleeder nipple on the ABS but I'll probably just take measurements after I attempt to bleed the ABS before we install the hard line.

**LockDots** · 02-01-2018, 01:50 PM

Originally Posted by golgo13

The challenge here is to get the thread pitch and depth of the bleeder nipple on the ABS but I'll probably just take measurements after I attempt to bleed the ABS before we install the hard line.

Buy an oe replacement.
Go to hardware store.
???
Return oe replacement

**golgo13** · 02-01-2018, 02:15 PM

Not to be smug, but which of these is the OEM bleeder nipple part?

**LockDots** · 02-01-2018, 02:39 PM

I have no clue. What I meant was to take the new pump (so you don't have to remove yours) to the hardware store to match up the thread pitch and size.

**golgo13** · 02-01-2018, 05:50 PM

Originally Posted by LockDots

I have no clue. What I meant was to take the new pump (so you don't have to remove yours) to the hardware store to match up the thread pitch and size.

Ah, okay. I misunderstood.

**NeilM** · 02-05-2018, 04:11 PM

Originally Posted by golgo13

The challenge here is to get the thread pitch and depth of the bleeder nipple on the ABS but I'll probably just take measurements after I attempt to bleed the ABS before we install the hard line.

Since I happen to have a spare ABS pump unit, I just removed the bleed nipple and measured its thread: M10x1.0.
A lot easier to do on the bench than in the car.

Neil

**golgo13** · 02-05-2018, 04:28 PM

Originally Posted by NeilM

Since I happen to have a spare ABS pump unit, I just removed the bleed nipple and measured its thread: M10x1.0.
A lot easier to do on the bench than in the car.

Neil

Hey, thank you for that. Looks like our guess was correct since that's the same as the hard lines on the Master Cylinder.

I was starting to look at purchasing a used unit off eBay, just to get a spare bleed nipple.

- - - Updated - - -

Also, Neil would it be possible for you to share a picture of what the mating surface looks like between the hex on the nipple and the threads on the pump side?

**golgo13** · 02-26-2018, 07:36 PM

So, to follow-up since most people don't bother on forums...

Well, after having changed a million things on the car to eliminate variables to deal with the low pedal engagement and squishy pedal I finally fixed it. BBK was not the answer but I can see why people would say that since it helps mask the poor braking with more braking force.

Yesterday I had a friend over to help me bleed the ABS. I read a lot of stuff online about how it's not needed and the system is self bleeding, etc etc but I wasn't convinced.

We performed one final bleed of the system to confirm there was no air trapped anywhere. We then removed the cap on ABS bleeder nipple shown:

We stuck an 11mm wrench onto the hex of the ABS bleeder nipple (it's super tight in there, get a wrench with a directional switch, for real) and then my caliper bleeding tube.

I hopped into the driver's seat and pumped the brake pedal to pressurize the line.

He then cracked the bleeder and a bubble about 1.5" in tube length escaped!

We did a couple more bleeds which got us a few more bubbles and continued until it was bubble free. Fluid came out new, so this wasn't a pocket of trapped fluid, it was just air that couldn't vent itself with normal ABS use.

So, if you're having a hard time getting your pedal back to normal after you've done the, "You need to use like 1L of fluid to get the brakes right, dude" and it still doesn't work or activating your ABS on street - I recommend you try this.

Have fun out there!

**SamGrant951** · 02-26-2018, 07:55 PM

Nice, will do since Im replacing booster/master right now. Thanks for the follow up.

**Mless5** · 02-28-2018, 09:50 AM

Thanks for the follow up! Do you bleed air out of the ABS unit with the car running or not? Also, was this the very last thing that you bled?

Thanks.

**golgo13** · 02-28-2018, 12:40 PM

Originally Posted by Mless5

Thanks for the follow up! Do you bleed air out of the ABS unit with the car running or not? Also, was this the very last thing that you bled?

Thanks.

No worries.

The car was not running at the time when we bled the ABS system. It was the very last thing we did.

**Crustashio** · 02-28-2018, 01:40 PM

Very interesting. Gonna have to try this when I pull my car out of storage. I swapped to another Master/Booster assy and it didn't do anything for my brakes.

What did you have to get out of the way to access it? Looks like the engine harness connectors were shoved out of the way, anything else?

**golgo13** · 02-28-2018, 04:51 PM

Originally Posted by Crustashio

What did you have to get out of the way to access it? Looks like the engine harness connectors were shoved out of the way, anything else?

I removed my strut tower bar
Disconnected the three harness connectors and two connectors that clip to the MAF and the ABS sensor then moved it up and out of the way
I removed Fuse box cover
Unclipped the plastic bracket that connects to the fuse box that holds the three harness connectors to the chassis
Removed the T10 bolts from inside the fuse box (My car only had one left, there are four of them)
Gently pulled the fuse box up and out of the way towards the driver's side
Used a small bungee cord to hold the connector bracket and fuse box out of the way by wrapping it around the hood shock
Unbolted the two 13mm(?) bolts that hold the ABS sensor in place (it sits above the pump on a paint matched 'C' shaped bracket
Moved the ABS sensor downward and out of the way
Disconnected the ABS DME wiring harness connector and pushed it down and towards the firewall

Don't forget to reconnect your ABS DME wiring harness connector or you'll be doing this all over again!

**golgo13** · 03-19-2018, 05:48 PM

To confirm, only the 96+ E36 M3 has a bleeder at that location.

For those cars, we're getting closer to producing complete modification kits for this bleeder relocation. Prices will be reasonable, as we're not looking to get rich off of this or anything mostly just to recoup our time and tools + machining.

This will include clear instructions with appropriate high quality components for your car that also include mounting solutions.

**NeilM** · 03-24-2018, 05:15 PM

Originally Posted by golgo13

For those cars, we're getting closer to producing complete modification kits for this bleeder relocation. Prices will be reasonable, as we're not looking to get rich off of this or anything mostly just to recoup our time and tools + machining.

Count me in as interested in this.

Neil

**golgo13** · 03-24-2018, 09:24 PM

Excellent! We’re thinking of doing 20 total for the first run, with five of them being reserved for my Car and a few local friends.

This is a small side thing we’re doing for fun, so it’s slow going. Probably have them ready in six to eight weeks or so. My associate is moving soon, so his assistance is delaying things slightly.