ABS actuator fail?

[Pamlico]

Hi all,
Jumped in my '97 LX450 couple of days ago, started and immediately put it in reverse. No brake pressure and no brake braking... Shifted to N, paused a moment, then had pressure and acted normally. ABS light on in dash for months, but no indication of an issue until now. Later in the day I drove it to dealer for inspection. Dealer is closest mechanic so didn't want to risk driving into Charlotte and having a brake fail.

Dealer says code 51 (stored pump motor locked) and must replace ABS actuator ($1500+ for part) and master cylinder ($700+ for part) plus labor and all the other charges they add on. Says part will come from Lexus dealer and that the part is Lexus only. When I questioned, "really? standard Toyota LC from same year won't work?" he replied, "look I'm not a parts guy. book says Lexus only". He never mentioned module...

My questions -

• Is the ABS actuator really a different part for the two badges?? I'm guessing no but don't know everything
• Could an ABS actuator impact the brake function in this way?
• Why would i have no brake pressure at startup and then feel and work normally after short idle?

All comments / suggestions appreciated.

Thanks

 

[Fj80oregon]

Have you tried resetting your abs light? If you need parts from a used rig I have a 96 fzj80 I’m parting out that was in working order when parked.
I would refer to the FSM and trouble shoot your brake system there are systematic steps to narrow down your issue.

 

[Pamlico]

Have you tried resetting your abs light? If you need parts from a used rig I have a 96 fzj80 I’m parting out that was in working order when parked.
I would refer to the FSM and trouble shoot your brake system there are systematic steps to narrow down your issue.

Hey. No I haven’t but I am picking up the truck today from the dealership and can try this weekend. Thanks for the suggestion. I may PM you if I need parts.

 

[Godwin]

If you do need a new MC, Advics on RockAuto is only about $75, and Toyota part = Lexus part = Toyota part.

This is the other item you need in replacing a MC Brake Booster Gauge for Any Toyota - https://www.cityracerllc.com/products/brake-booster-gauge-for-any-toyota

 

[Pamlico]

If you do need a new MC, Advics on RockAuto is only about $75, and Toyota part = Lexus part = Toyota part.

This is the other item you need in replacing a MC Brake Booster Gauge for Any Toyota - https://www.cityracerllc.com/products/brake-booster-gauge-for-any-toyota

Thanks Godwin

 

[MissahPapaJ]

If it were me id be contemplating a ABS delete but if you like the added security of a functioning ABS system it may be worth the coin, that being said the ABS parts are spendy across the board and the entire system is on borrowed time at this age.

 

[Kernal]

Code 51, locked/stuck ABS motor has a known cause, rust inside the motor/armature case. Others have opened up the ABS motor and cleaned it out, removed the rust and the ABS started working again.

No braking: does that mean the brake pedal goes to the floor so no braking effect, or that it's very difficult to press the brake pedal and no braking effect??

Vacuum line to the brake booster intact?

A little off-topic FWIW: regarding the ADVICS Master Cylinder: some weeks ago I ordered that part (ADVICS/AISIN BMT-046) from RockAuto, arrived with poor machining on the rear mounting surface, returned for a replacement, same defect, returned again, third had same defect. ADVICS sales division initially said not a problem, then after I sent photos they said return it to where you purchased it, but later the head of ? Dept at ADVICS said, no problem, OK to install. My concern was that if one machining operation was that far off ie: compared to the original Toyota MC, how would anyone know if the bore of the MC where the piston rides was machined correctly or not?? ADVICS never answered that question. FWIW



Here's the link to the discussion on the stuck ABS motor:

Thread 'ABS DTC code 51'

Jul 13, 2013

hi everyone,

ABS light stayed on after using center diff lock.
removed battery ground, same problem.
removed short pin and jumped E1 and Tc in diagnostics.

code 51- 5 blinks, pause, 1 blink, longer pause. then repeat.

DTC 51 is "ABS pump motor is locked, open in pump motor ground" according to the manual.

tried to reset by pushing on brake pedal 8 times in 3 sec. i don't think i was able to press 8 times in three seconds so i removed the UCU B fuse.

ABS light still on.

WHERE IS THE ABS PUMP MOTOR? IS IT THE SAME AS THE ACTUATOR?

I can't find it in the repair or...

• lt403
• Replies: 58
• Forum: 80-Series Tech

• 

 

[jpoole]

More info that may help including a fairly easy and very inexpensive fix that I employed to resolve code 51, read to end of 2nd page for more good tips:

Post in thread 'ABS DTC code 51'

May 30, 2024

I wanted to share a relatively easy fix for code 51 that may apply in some situations. On my '97 I noticed the ABS light earlier today and pulled the codes after a general inspection and test of the CDL, etc. The code that came back was 51 so I then hot-wired the abs pump to see if it would turn over with direct power applied. This is something that I do during brake bleeding so I was familiar with how the pump should sound. When I hot-wired the pump the sound/feel of the pump lead me to believe that motor was ok electrically but blocked mechanically, which turned out to be the case.

I...

• jpoole

• 

Thread 'HELP abs code 51. What do I fix ?'

Jan 8, 2019

abs light is showing code 51 actuator circuit or whatever it says. How do I fix it. The FSm just shows removal
Thanks

• tromz
• Replies: 21
• Forum: 80-Series Tech

 

[Kernal]

^^^That's the thread^^^

 

[Pamlico]

If it were me id be contemplating a ABS delete but if you like the added security of a functioning ABS system it may be worth the coin, that being said the ABS parts are spendy across the board and the entire system is on borrowed time at this age.

This is true

 

[Pamlico]

Code 51, locked/stuck ABS motor has a known cause, rust inside the motor/armature case. Others have opened up the ABS motor and cleaned it out, removed the rust and the ABS started working again.

No braking: does that mean the brake pedal goes to the floor so no braking effect, or that it's very difficult to press the brake pedal and no braking effect??

Vacuum line to the brake booster intact?

A little off-topic FWIW: regarding the ADVICS Master Cylinder: some weeks ago I ordered that part (ADVICS/AISIN BMT-046) from RockAuto, arrived with poor machining on the rear mounting surface, returned for a replacement, same defect, returned again, third had same defect. ADVICS sales division initially said not a problem, then after I sent photos they said return it to where you purchased it, but later the head of ? Dept at ADVICS said, no problem, OK to install. My concern was that if one machining operation was that far off ie: compared to the original Toyota MC, how would anyone know if the bore of the MC where the piston rides was machined correctly or not?? ADVICS never answered that question. FWIW



Here's the link to the discussion on the stuck ABS motor:

Thread 'ABS DTC code 51'

Jul 13, 2013

hi everyone,

ABS light stayed on after using center diff lock.
removed battery ground, same problem.
removed short pin and jumped E1 and Tc in diagnostics.

code 51- 5 blinks, pause, 1 blink, longer pause. then repeat.

DTC 51 is "ABS pump motor is locked, open in pump motor ground" according to the manual.

tried to reset by pushing on brake pedal 8 times in 3 sec. i don't think i was able to press 8 times in three seconds so i removed the UCU B fuse.

ABS light still on.

WHERE IS THE ABS PUMP MOTOR? IS IT THE SAME AS THE ACTUATOR?

I can't find it in the repair or...

• lt403
• Replies: 58
• Forum: 80-Series Tech

• 

Thanks. I have seen a thread on the rust removal and before I do a delete I will try to clean the motor and reset the module, but I'm not excited about 1-1.5k for a part that should be 25% of that.part. I'm in the middle of a move this weekend so timing could be better.

No brakes means that at startup there would be no/little pressure and pedal would go easily to the floor or nearly, and it would start moving in my flat driveway as soon as i put it in reverse. I would have to shift to N and pump to get it to stop. If I then wait a few moments after pumping the pedal it went away and acted normally... well normally for an 80. I have not experienced the firm or wood pedal that others have mentioned.

 

[Kernal]

Sounds like your Master Cylinder has an internal leak ie: fluid getting past the seals of the piston inside the bore of the cylinder:

Toyota has a MC rebuild kit, 04493-3D010, but IME the issue may not be just old shrunken seals, it could also be pitting inside
the MC allowing fluid to leak past the seals so you wouldn't know until you opened up the old MC. The ADVICS master cylinder,
BMT-046 is ~ $80 (RockAuto) and should be identical to the Toyota part. However IME as mentioned above, the ADVICS parts (3) I received recently had poor machining/quality control that I doubt would be acceptable to Toyota even if just a cosmetic flaw. FWIW

Example poorly machined (new) ADVICS (AISIN) Master Cylinder (~April 2026):

 

[Pamlico]

Sounds like your Master Cylinder has an internal leak ie: fluid getting past the seals of the piston inside the bore of the cylinder:

Toyota has a MC rebuild kit, 04493-3D010, but IME the issue may not be just old shrunken seals, it could also be pitting inside
the MC allowing fluid to leak past the seals so you wouldn't know until you opened up the old MC. The ADVICS master cylinder,
BMT-046 is ~ $80 and should be identical to the Toyota part. However IME as mentioned above, the ADVICS parts (3) I received recently
had poor machining/quality control that I doubt would be acceptable to Toyota even if just a cosmetic flaw. FWIW

View attachment 4158888

Example poorly machined (new) ADVICS (AISIN) Master Cylinder (~April 2026):

View attachment 4158891

Interesting. Is it possible that I have two separate topics, one with the MC (which was replaced new in '21) and the ABS system? Fluid level seems ok fwiw.

The photo almost looks like a possible casting issue. Wouldn't it be hard to get a seal with that surface?

 

[jonheld]

Dealer says code 51 (stored pump motor locked) and must replace ABS actuator ($1500+ for part) and master cylinder ($700+ for part) plus labor and all the other charges they add on.

The ABS actuator assembly (44510-60010) has a LIST PRICE from Toyota of $1,138.26 and can be purchased from a Toyota dealer for $867.60.
The master cylinder (47201-60551) has a LIST PRICE of $340.47 and can be purchased from a Toyota dealer for $222.91.

 

[Kernal]

"The photo almost looks like a possible casting issue. Wouldn't it be hard to get a seal with that surface?"


Compared to the old (but OEM Toyota) MC the mating surface on the Toyota part was perfectly flat with a slightly deeper weep groove (not shown in the photo above). The ADVICS aftermarket part in the photo above looks to my eye (and finger) that a machining process started then stopped ie: it either should not have started (my best guess) or it never completed a pass. Look closely at the machining marks, normal for most of the surface, then different for the extra cut.

About sealing. IDK if that is super-critical ie: there is a weep groove at the 6 O'clock position (on both the Toyota and ADVICS MC's)
so the seal IMO is more to prevent contamination into the area between the back of the MC piston and the pushrod for the booster ie: not a vacuum seal. So with the gasket and maybe a slight smear of a gasket sealer on that side it should be waterproof, leaving a small area unsealed at the 6 O'clock position for the weep groove ie: to let you know if the MC piston seal is leaking rearwards.

FWIW the point I made with ADVICS tech was not so much the defect above, but wondering if one machining operation was off then what's to say the bore of the cylinder where the piston seals are located wasn't also a bit off? The smallest error when machining the bore can cause the MC to fail (ie loss of braking). They didn't seem concerned even considering there were issues with poorly machined Toyota (ADVICS/AISIN) MC's not too long ago.

 

[alia176]

You've been ignoring the ABS fault light for "months", as you put it! You're not using the ABS, and apparently, you don't need it so why not just chuck it per the ABS/LSPV thread in this forum? So, that's one issue resolved. You're welcome. Incidentally, my ABS light was one for 12 years before the bulb burned out. I am part time rear wd so the front sensors weren't picking up the ABS signal!

Now, for the second issue, you might indeed have a failing MC so I'd suggest replacing the MC and the brake booster all at once. That's what I just did few weeks back when the OEM BB finally sprung a leak in the diaphragm. Everything in our rigs is getting old so I'd replace things as often as needed for a peace of mind and the safety of your family. I purchased the MC and BB from CityRacerLLC per another thread on this board. Validating browser… - https://forum.ih8mud.com/threads/best-aftermarket-brake-booster-consensus.1382102/

Good luck amigo.

 

[Pamlico]

You've been ignoring the ABS fault light for "months", as you put it! You're not using the ABS, and apparently, you don't need it so why not just chuck it per the ABS/LSPV thread in this forum? So, that's one issue resolved. You're welcome. Incidentally, my ABS light was one for 12 years before the bulb burned out. I am part time rear wd so the front sensors weren't picking up the ABS signal!

Now, for the second issue, you might indeed have a failing MC so I'd suggest replacing the MC and the brake booster all at once. That's what I just did few weeks back when the OEM BB finally sprung a leak in the diaphragm. Everything in our rigs is getting old so I'd replace things as often as needed for a peace of mind and the safety of your family. I purchased the MC and BB from CityRacerLLC per another thread on this board. Validating browser… - https://forum.ih8mud.com/threads/best-aftermarket-brake-booster-consensus.1382102/

Good luck amigo.

All valid points and I know using a 30 year old vehicle daily so I expect some fatigue and will most likely go the delete route if I find that the pump isn't repairable (i'm not buying a new one). But if I can get it to work I like the idea of ABS in the winter in western NC. I already planned to my an MC ahead of time and put it on the shelf if i didn't need it. Can add a BB to the list

 

[Marvelicious]

All valid points and I know using a 30 year old vehicle daily so I expect some fatigue and will most likely go the delete route if I find that the pump isn't repairable (i'm not buying a new one). But if I can get it to work I like the idea of ABS in the winter in western NC. I already planned to my an MC ahead of time and put it on the shelf if i didn't need it. Can add a BB to the list

I'm with you on that one. There's a lot of hate for ABS on here, but even 30 year old low tech ABS can work pretty well when the road gets slick (provided it DOES work). That said, I'm pretty sure it's not the issue that's letting the pedal go to the floor.

 

[Batameez]

That Advics machining defect won't affect performance. It serves no hydraulic sealing. Save your money and run it, though I recommend you get a new paper gasket or cut one out of thicker gasket paper in case you're worried the boogie man will sneak between your master and booster. Speaking of, this is a great time to replace the booster.

 

[alia176]

I'm with you on that one. There's a lot of hate for ABS on here, but even 30 year old low tech ABS can work pretty well when the road gets slick (provided it DOES work). That said, I'm pretty sure it's not the issue that's letting the pedal go to the floor.

I think "hate" might be a strong word to use in this application. But, the ABS functionality is greatly diminished with the fat arse pigs that we are driving with large tires these days. Even on my best day, I was never able to lock up and activate the ABS on dry pavement using 285s. However, ABS does have its role to play on snow/ice, particularly for drivers who aren't old AF as some of us are.

Last sat a local 80 owner rode in my rig for helping me troubleshoot an issue. I demonstrated for him acceleration with the turbo, and deceleration with my awesome braking system. He was beside himself He has 285s and never been able to lock up and activate ABS on dry pavement, and here I am just about locked up all four tires and squealed the tires a little.