rebuilding the old ABS unit and possible bad accumulator?

[darock]

Hello,

I started the ABS teardown today.

When I depressurized the system through the bleeder I got nothing but foam again. The system was bleeded twice during the summer to get rid of the old brown foam that was in there for the last 20 years.

Why did it foam again?

possible bad accumulator?

How often does the ABS support full stops with ABS working before the pump kicks in to pressure up again? Mine would do two but start to pressurize during the second.

The solenoids look pretty clean inside. There is a lot of dirt outside but nothing inside.

Cheers,
Bernhard

[Kaz-kzukNA1]

Hi, Bernhard.
It all depends on many conditions.
Based on more than 100 samples, if the classic ABS was healthy, the ABS was just flushed or re-pressurised, ABS was activated fraction of a second (felt like below 0.5sec) each time from about 15mph max while the tyre was cold on dry surface, then I always got the ABS pump being triggered immediately after ABS activated 3 times.

How did you bleed/flush the ABS accumulator?
How much fluid did you recover into the ABS SST T-wrench at the very beginning of the service?
Did you activate all four solenoids manually?
How did you pressurise the accumulator before flushing each solenoid?

With classic ABS, no matter how you flush the system, eventually, you will get foamy fluid if the ABS was triggered and the ABS pump triggered while the car was moving.

If you left even a tiny single bubble in the ABS reservoir, it will result in foamy fluid when it was pushed through the needle like super tiny port diameter of the solenoid with enormous back pressure from the accumulator.
It's the effect of the surface tension going through tiny hole.

You probably experienced the same thing if you played with the soap bubbles when you were very small.
Depending on how fast/slow you blew the straw or the diameter of the straw itself, the size of the bubbles changed.

You can't judge the condition of each solenoids by just looking at it.
You need to either activate it while there is mega high pressure available inside the accumulator to check any slow leakge or you need to use compressed air with some sort of jig to confirm no leakage or stuck closed situation.
It's much easier to diagnose it while the system is still on the car.


If you only activated (1st time) the ABS under fraction of a second and if the ABS pump kicked in the next time (2nd time) you activated the ABS, then you are very likely to have leaky solenoid issue and if you managed to lock the wheel based on the other thread, you also seem to have stuck cloesd solenoid issue as well.

Depending on how much fluid you managed to recover, you may have pin hole at the bladder of ABS accumulator.


Kaz

[darock]

Hey kaz,

I actually built a tool to flush the ABS. Its basically the same as the T wrench without the T. It fits on the square bleeder on the pump and has a hole to put a hose on it the same time. I use a simple glass to capture the fluid.

https://farm8.staticflickr.com/7477/16218095165_d00d3a2e0d.jpg
https://farm9.staticflickr.com/8629/16030579078_8a7db21298.jpg

I can measure how much I got out of it this time, next weekend. I still have it in the glass. The car is sitting for 2 month already so some of the fluid has probably escaped back into the reservoir through the leaking solenoids.

I bleeded the system by powering the pump by hand and measuring the pressure sensor. Then opened the bleeder. I did not get any bubbles after the third time and did it another two times to really make sure every bit of dirt and air is out of the system. Filled with fresh fluid. That was shortly after I got the car and got annoyed by the chirping pump all the time. I also gave it a lot of exercise whenever I could.

What I will do after I put the thing back together is pressurizing the system on the bench and exercising the solenoids. Monitor the fluid level in the reservoir over night.

I also think about disassembling the pump or at least the driving mechanism of it. I don't think it made that chirpy noise when it was new. Probably a good idea to give all the gears in there a little clean and some grease ... maybe some new bushings and bearings if needed.

Bernhard

[Kaz-kzukNA1]

Seems like you didn't flush each solenoids one at a time previously and only flushed the high pressure side of the system.
If this was the case, then I'm afraid when you exercised the ABS a lot and triggered the ABS pump for the first time, the air was sucked back into the accumulator.
You must flush solenoid one at a time and either replace the entire returned fluid with fresh one or wait for at least 30min before moving onto the next solenoid.

If you disassemble the pump, you will see two main parts. The motor and the pump.
At the end of the electrical motor, you will see the gear mechanism and that is connected to the eccentric bearing. This bearing will push back and force the plunger inside the pump resulting in sucking the fluid from the ABS reservoir and pressurise the accumulator.

The noise seems to be coming from this gear mechanism. If you look at it, you will notice that the grease is hardened and dried.
If you look at the motor armature, you will notice the wear at the brush and so unless you do DIY, it is not cost effective to overhaul the ABS pump. I think the official name for both the motor and the pump is different but I just use 'ABS Pump' when discussing about the motor and pump assy.

When the pump was new, the sound was low tone and not that annoying. You could say it sounded like cranking the engine with very weak battery and never managed to start the engine. It sounded like goo---goo---goo---.

Then, once the ABS got older, the sound turned into somewhat tappety/rattling noise but without squeaking/screaming. Like rattle snake.

Once the system past this point and got very old, then the noise will turn into squeaking/screaming high pitch/tone annoying noise.


By the way, before you decide to overhaul your classic ABS, I hope you confirmed the generation of your system with Warren. His kit is for the 1st gen.
You can check the spec based on the info here;

http://www.nsxcb.co.uk/showthread.php?6286-NSX-Health-Check-Service&p=75279#post75279
(http://www.nsxcb.co.uk/showthread.php?6286-NSX-Health-Check-Service&p=75279#post75279)
http://www.nsxcb.co.uk/showthread.php?10434-ALB-ABS-generations

Kaz

[darock]

Oh, ok, I see its absolutely my own fault that I got foamy fluid again. Will do it again :D

DIY bushings or bearings for the pump is no problem. I have my own little lathe and actually love to do special stuff like that.

My ABS is definitely a first gen with four separate solenoids.

I am still thinking about upgrading to the newer ABS. A little over 2000 Euros for the conversion is a lot of money and I did not want to spend that much on the car.
On the other hand, right now would be the best time to do the upgrade. The old abs is out and needs work. I could do the conversion and do the refurb of the ABS later and store it in a box if I want to go back to totally stock some time for car value reasons.

Would you always go for the upgrade?

Bernhard

[darock]

I am pretty sure I will do the upgrade to the newer ABS because its a safety aspect for me to have the best possible ABS. Wrecking the car is my biggest fear and I somehow don't thrust that old ABS.

Anyway ... I did some investigation on the pump because I was curious.

As forum people like pictures ... here we go ...

The grease inside the pump drive was dry. I cleaned it and filled with new grease.
https://farm8.staticflickr.com/7574/16246066482_529760a1e5.jpg
https://farm8.staticflickr.com/7571/15624486434_c99f6aeb13.jpg

The pump module itself looked totally clean inside.
The excentric bearing is in good shape like all the other parts. Did not find anything wrong with them. Also the rear bushing of the pump motor was ok.
https://farm8.staticflickr.com/7575/16246908325_d56aebed2f.jpg

Found some hoses and made up a little test rig.
https://farm8.staticflickr.com/7546/16245050441_79000d6eb1.jpg

Still makes chirping noises and rattles. I think the gears are already worn due to missing/hardened grease.

I will put the abs back together and store it.

The design of the pump is actually pretty clever. You can easily fill the pump drive with fresh grease from the outside if you remove the motor housing and the upper screw holding the plastic motor base plate. The small hole goes directly into the upper grease reservoir inside the "gearbox".

Bernhard

[darock]

Here is a picture of the valve assembly after I took off the cap.
https://farm8.staticflickr.com/7516/15646897993_443964ea36.jpg

Don't know what that stuff is that sticks to all the parts but its definitely not good that it is there. Its pretty obvious why the abs did not work as intended. The same stuff probably also sits inside the solenoids and makes them stick or leak.

I made the following two earlier but forgot to post them.
https://farm8.staticflickr.com/7475/16038739397_442312f030.jpg
https://farm8.staticflickr.com/7555/15602179734_742e263e39.jpg

It was actually not too bad around the solenoids. The dirt is only for the outside. Under the O-Rings everything was clean around the solenoids. I did not expect to see the dirt inside the valves after taking the solenoids off though.

Bernhard

[nobby]

great write up and thanks for sharing.

The new ABS version is well worth the funds ... you thinking was just like mine. One of the best mods I have done to date on my car. night and day difference on braking

[darock]

great write up and thanks for sharing.

The new ABS version is well worth the funds ... you thinking was just like mine. One of the best mods I have done to date on my car. night and day difference on braking

I am glad I can contribute to this great forum community a bit!

BTW, love the picture of your yellow NSX. Great color for the car. Don't know why everyone is so crazy about the silver ... nowadays every second car is silver ... yellow really stands out.

Hope I find time to finish the ABS next weekend with some more pictures.

Bernhard

[darock]

No update on the ABS refurbish but got something else, thanks to UnhuZ

https://farm9.staticflickr.com/8566/15755546993_af5c3d5baa.jpg

which goes onto this:
https://farm8.staticflickr.com/7411/16187908418_8276ccc978.jpg

and that's how it looks right now
https://farm9.staticflickr.com/8660/16373818961_568d44afce.jpg

Its amazing. Like Honda intended to upgrade the ABS on all NSX.

Took a little time to figure out which brake line goes where. I just put it on without tightening. Better to mock up the assembly on the bench than trying to get it right on the car itself.

Bernhard

[UnhuZ]

Hi,

Glad to see it all come together ;)

and yes, this upgrade it's a must, but sadly for me and gladly for you, i had to let it go.

i just replied to your last PM... i'm still sad about the ETA of the last line (the biggest)

Nuno

[goldnsx]

The updated ABS resulted in -5m in dry and -8m in wet conditions. More than well worth it. It's far easier to maintain and weighs less. I'd not put a single £ in updating the old unit v1.0.

[darock]

The mechanical part of the new ABS is in:

https://farm8.staticflickr.com/7399/16222576838_53e9ec4978.jpg
https://farm8.staticflickr.com/7388/16409294342_9c1659c662.jpg

I hope those pictures help others doing the swap on a LHD. It took me some time to find out which line goes where because I did not find pictures and the part number also does not clearly indicate it.

No line touches another one and I even reused the old plastic clip. Getting the front left line in was a bit fiddly but doable.

The only thing missing is the connection of the front right wheel because I did not get the line with the kit. Its also not available from Honda until at least April. Actually its not too bad because the old line can be reused easily which safes a lot of time. It clears the new ABS nicely. I just need to bend a short line that goes across the ABS unit and join it to the old line with a brake line coupling.

You only realize how small the new ABS unit actually is when you bolt it on the car. It really looks a little lost inside the big front compartment.

I also took the front calipers off for inspection as Kaz suggested. Despite they look perfectly without any corrosion the floating pins are stuck. Already have the rebuild kit here so I will give them a nice clean and refurb.

Started to snow again and got cold so I had to stop. Next time -> Put in the wiring and remove the right driveshaft for an overhaul.

Bernhard

[darock]

Gone through the floating pins yesterday evening.

Some Idiot in the past applied copper grease to the pins and thats what caused them to stick. They stuck so bad, that the brake discs are worn only on the inside.

Probably the same idiot torqued the bolts holding the caliper to the carrier with the impact wrench adjusted to "kill". Needed a big lever to brake them loose. That's something I absolutely can't stand.

I cleaned it and used some spare NIGLUBE RM I had left from a Integra Type-R brake rebuild. Did not have enough so I searched the web. Honda asks $45 for 100grams. Mitsubishi only $19. Mitsu part number: MZ101616EX

Floating pins are now moving like they should.

The calipers itself are in perfect condition. Could push the pistons back by hand without much effort. Applying just a bit of air pressure made them move out a bit and retract again after releasing the pressure. I will leave them alone for now.

Bernhard

[darock]

https://farm8.staticflickr.com/7373/16472559665_028cc88bfa.jpg

http://www.prodng.com/image.axd?picture=2012%2F11%2Fdoublefacepalm.jpg

not much more to say about that. Would love to meet the "mechanic" who did this ... Just to ask him WTF he was thinking when he messed that up ...

I polished all pins on the lathe because they had some corrosion and with the NIGLUBE RM it now floats like new even after sitting for a week on the shelf without moving.

Bernhard

[darock]

Even if nobody is interested its still useful information.

Nipparts brake discs J3304029 even though they are listed for the NSX DO NOT FIT

https://farm8.staticflickr.com/7324/16339713418_88b53ec745.jpg

Learned this today ...

Beside finding even more copper grease inside the rear caliper brackets ...

Bernhard

[cadrega]

Great writeup - how much was the new unit?

[darock]

Thanks. I was lucky to get the set from Unhuz for less than 1400 with a used ABS unit. Normally it will be little over 2000 from known vendors with a new unit.

I have a really hard time getting the front right brake line (lhd) which is on backorder for at least march. But I came up with a way simpler solution I will post when I have it finished. Sadly too cold right now to do work on the car.

bernhard

[darock]

Finally fitting brake discs arrived. All four.

DBA street slotted
https://farm9.staticflickr.com/8618/16599024132_e22a9690a6.jpg

Still waiting for the brake lines so no progress on the brake system. Sorry, but Goodridge UK is the worst vendor I have dealt with in years.

But the Pride GTLW fits nicely :D
https://farm8.staticflickr.com/7281/16413795809_f5e394de7b.jpg

Bernhard

[darock]

I borrowed a professional brake line toolkit and made up the adapter pipe to connect the new ABS to the old right front brake line (LHD). I just need to cut the old line at the right length and ad the right beading to connect to the adapter pipe.

https://farm9.staticflickr.com/8767/16867245349_76a958b355_b.jpg

Also the Goodridge brake lines arrived. Just took 3 Month or so ... seriously ... never had so much trouble getting a part ...

https://farm8.staticflickr.com/7634/16846037377_6055f9c462_b.jpg

Still waiting for the right inner CV joint from the US and some small parts to put the car back together and on the road ...

Bernhard

[Pride]

Also the Goodridge brake lines arrived. Just took 3 Month or so ... seriously ... never had so much trouble getting a part ...

https://farm8.staticflickr.com/7634/16846037377_6055f9c462_b.jpg


Bernhard

Sorry to have to tell you this Bernhard but you've been sent a set of FAKE Goodrich brake pipes.:(
The genuine article comes in bright silver, all fake pipes come in dark finish.
Google it, you'll see.:rolleyes:

[Rdevelopments]

Sorry to have to tell you this Bernhard but you've been sent a set of FAKE Goodrich brake pipes.:( The genuine article comes in bright silver, all fake pipes come in dark finish. Google it, you'll see.:rolleyes:

Google a bit more And you'll find genuine goodridge comes in multiple colors...

http://goodridge.brakes-hoses-fittings.co.uk/brake-line-colours.php

[Pride]

Google a bit more And you'll find genuine goodridge comes in multiple colors...

I don't need to as I was only trying to wind Bernard up after his long wait for them.:)

[darock]

I don't need to as I was only trying to wind Bernard up after his long wait for them.:)

:D

I hope this fits ... I am so fed up with not fitting parts, stupid sales managers and postal services loosing parcels ... Especially postal services and customs ...

Just want to finish the car and go for a drive ...

Bernhard

[Pride]

Bernard, what make and type of brake pads are you installing with your DBA discs and why those ones???

[darock]

I got the Dixcel ES pads. I planned to go with EBC Yellowstuff but the ES pads seem to be an interesting choice and I like to try new stuff.

Bernhard

[darock]

Just because it looks cool and I know forum guys like pictures :D

https://farm9.staticflickr.com/8727/16950085530_4e4b8a6945_b.jpg

Hope to finish the car soon ...

The left rear brake line connection does not want to come apart ... I hope a little heat does the job otherwise I have another annoying problem.

Bernhard

[darock]

Made some more progress today.

Putting those rollers back together is a little fiddly ... and the Honda lube stinks like GL5 gear oil.
https://farm8.staticflickr.com/7670/16558754404_4416312bb5_c.jpg

I also assembled the caliper floating pins with new boots and the right grease. Actually two different. On inside on the pin, one outside in the boot.
https://farm9.staticflickr.com/8767/17155250356_833b5505f7_c.jpg

Its so nice when you put it back together and everything fits ... those good ridge brake lines are top quality, as expected.
https://farm8.staticflickr.com/7713/17181172525_48d8202caf_c.jpg

ABS is finished. Custom brake line to connect the old right front line to the new abs fits nicely. I think that's worth sharing. Haven't seen pictures where this has been done before. As the right front line was NLA from Honda Austria this was really the only chance to make it work.
https://farm8.staticflickr.com/7698/17180587461_084bb4291f_c.jpg

[darock]

LHD loom by Kaz
https://farm8.staticflickr.com/7597/16993659440_036e19ddf1_c.jpg

Loom routed inside the cabin using the spare grommet next to the main loom. Yes, I misrouted the +12V wire ... I found that out after I had the glovebox back together. Need to change that.
https://farm9.staticflickr.com/8825/16995000439_be07c10ed3_c.jpg

Random picture of the loom cable tied to the brake line behind the interior fan.
https://farm8.staticflickr.com/7650/17179530012_b1297528ea_c.jpg

And this is how she looks right now ... Old driveshaft is back in. Will sort out the right driveshaft later when I have access to a lift.
https://farm9.staticflickr.com/8760/17181175035_645fe33322_c.jpg

Bernhard

[darock]

http://www.nsxcb.co.uk/showthread.php?12905-Paging-kaz-Please-help-Abs-conversion-does-not-work-(

Anybody an idea?

Bernhard