ABS Booster Pump - Repair or Replace? Part Sources? Rebuild in DFW, TX (4 Viewers)

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If LRIwater doesn't run with it, I'd be interested to see how much to send pump &motor to OZ so i can pull it down.
 
It's all yours 100 TD. Thanks for the thought, though!
Yes, mileage is not a factor in this case. Bad Brake fluid quality is detrimental to these systems, meaning I think fluid quality is more of a factor than mileage. I’m sure atmosphere conditions, temp, etc all play a role. Also someone who sits in stop and go traffic is more likely to wear out a pump more than someone who just drives highway.
i just got a new booster and accumulator from ebay and had it installed by an Indy. The problem is now that the booster will occasionally activate during driving and I can feel it when I step on the brake pedal. I don't think I felt the booster before. If I step hard on the pedal, I can activate the booster as well. Can y'all tell me if this is normal?
 
i just got a new booster and accumulator from ebay and had it installed by an Indy. The problem is now that the booster will occasionally activate during driving and I can feel it when I step on the brake pedal. I don't think I felt the booster before. If I step hard on the pedal, I can activate the booster as well. Can y'all tell me if this is normal?
Yes this is normal for the booster to operate under driving and braking conditions.

However if the pump is making more noise or vibration than you feel is appropriate, you might have an issue. The booster should sound like a faint electric pump from inside and should not be loud or rattle for any reason.
 
This is the sound I am getting.

https://youtu.be/S2EyQMtwGuk

I bought a rebuilt pump motor, installed a low mileage pump and accumulator, rebuilt the master cylinder while I was there, and bled the brakes. Still have pretty much the same sound although now it's less random and more of an on / off on a tempo and only for about 1-2 minutes when it's "cold". For San Diego / Phoenix, that is like upper 50's. In the video you can see the movement of the fluid in the center baffle when the noise occurs.

The only thing that I haven't done is pay the $145 to have the dealer flush and bleed the brakes, although I put over two quarts to fill and bleed the system during the bleeding process. Ay caramba...

An update: I had the dealer flush and bleed my brakes ($140) with the understanding that if it didn't work, they would bleed it for free when I replaced the whole assembly. The dealer brake bleed with the Toyota special tool was my last attempt before buying a whole new assembly. As anticipated, the brake bleed didn't work. Camelback Toyota has the best deal on the whole assembly (see attachment) as pointed out by Cop9980. My dealer matched that price. I installed it yesterday. It was whisper quiet this morning... Success, finally, but oh so painful on the wallet.

Master Cylinder Assembly.jpg
 
If you have a newer LC or LX (PN 47050-60043) the price seem to be in the low $1800's. Refurbished on ebay for half that. Also, for noob LX owners like me, don't include "lexus" with the part number when searching google, cause results will always be more expensive. I will be replacing mine, unfortunately, in the next month.
 
The two screws holding the wire on the bottom of the ABS unit rusting is interesting.

I recently replaced the ABS for a local mud members 98LC w/150K. I saw the same rust.
View attachment 1556250
I clean up the wires and install them on the replacement ABS unit. I added some dielectric grease in hopes to give some future protection from rust.
View attachment 1556256
It was a clean 98LC, not some rust bucket. I became concerned The King, The Unicorn & The black Knight my also have this condition.

So I grabbed my mirror and a flashlight and started inspecting them. The King first, be the oldest, and have repeatedly cleaned the engine compartment over 14 year, I fear the worst. My thinking was power-washing was filling the boot covering the wires with water. I'm happy to report; The King's were not rusty. The Black Knight also looked good.

But The Unicorn I'm not sure what I'm seeing, either rust or someone coated with a grease. So I'll be pulling master unit assembly to inspect closer.
View attachment 1556264

Truck has no rust.

60AB9FA2-3C08-4EF6-9E05-DE1D19AFCF53.jpeg
 
Those ABS to booster pump screws/wires are one of my newest inspection item. I'm finding on 2 out of 7 rust free rigs. At first I thought we may have a leak in ABS unit. In which brake fluid weeping out wetting, then attracting moisture. But at this point I'm not finding leaks. It may be spillage or overflow wetting.

I'll be posting my inspection and what I do to correct and protect in the near future.

Anyone with old Brake Master assembly or parts of, I'm very interested in. I'd like to dissect and see if I can find some common issues that we may be able to protect against. Please PM me if you care to part with.

1 Wires ABS unit 9-15-18.jpg
2 Wire ABS unit 3-3-18.JPG
 
So is ebay the best option for getting a rebuilt unit in a timely manner? I'm in need of one.

I wonder if the just replace the commutator and brushes or of they do a complete rewind, bearings ect. If I could find a parts source for a commutator I could DIY, but ive been unable to find anything.
 
I received my motor in 5 days from the eBay seller listed above. I have seen two shops that rebuild the motors. One of them rebuilds the one you send to them. The other one in California has stock but not what they policy is.
 
Those ABS to booster pump screws/wires are one of my newest inspection item. I'm finding on 2 out of 7 rust free rigs. At first I thought we may have a leak in ABS unit. In which brake fluid weeping out wetting, then attracting moisture. But at this point I'm not finding leaks. It may be spillage or overflow wetting.

I'll be posting my inspection and what I do to correct and protect in the near future.

Anyone with old Brake Master assembly or parts of, I'm very interested in. I'd like to dissect and see if I can find some common issues that we may be able to protect against. Please PM me if you care to part with.

View attachment 1664186 View attachment 1664187

Good idea for a regular look at these contacts to ensure the corrosion is mitigated. I think the cause is condensation. The cap isn't air tight and moisture may travel from where the wires pass through the cap, and also through the edge at the top of the cap.

My contacts were crusty but it cleaned off pretty well. Used a dremmel with a wire brush attachment on low speed to get the crud off (battery disconnected). Coated with ETC 180 which is anti corrosion, and then covered that with dielectric, and sealed cap edges with with a smear of dielectric to help keep moisture out.
 
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Good idea for a regular look at these contacts to ensure the corrosion is mitigated. I think the cause is condensation. The cap isn't air tight and moisture may travel from where the wires pass through the cap, and also through the edge at the top of the cap.

My contacts were crusty but it cleaned off pretty well. Used a dremmel with a wire brush attachment on low speed to get the crud off (battery disconnected). Coated with ETC 180 which is anti corrosion, and then covered that with dielectric, and sealed cap edges with with a smear of dielectric to help keep moisture out.
I busted an ABS case open at point the wire connection. Appears that in manufacturing process, the plastic is molded around the leads very tightly and for a good distance. This reaffirmed my opinion brake fluid is not sweeping out of casing at leads. There is a seal on the face where fluid could leak from next to boot over screws. But I'm not finding any leakage there either. I believe the cap is air tight, if fasten properly. We may never know for sure, but lack of clues indicate spillage.
 
I busted an ABS case open at point the wire connection. Appears that in manufacturing process, the plastic is molded around the leads very tightly and for a good distance. This reaffirmed my opinion brake fluid is not sweeping out of casing at leads. There is a seal on the face where fluid could leak from next to boot over screws. But I'm not finding any leakage there either. I believe the cap is air tight, if fasten properly. We may never know for sure, but lack of clues indicate spillage.

The cap may be airtight when new, I think with age and repeated under hood heat cycles that boot looses its elasticity and allows moisture to get in- and condensation to form which doesnt dissipate too quickly- which leads to corrosion at the terminals. Dab of dielectric around the edge of the cap, and where the wires lead in may help.

Im not sure there is a solution to making that area water tight with out using rtv to seal the cap. Cleaning the screws and terminals and then packing the top of the screws and terminals with dielectric as you have done should do a decent job of mitigating the chance for corrosion to reoccur.
 
The cap may be airtight when new, I think with age and repeated under hood heat cycles that boot looses its elasticity and allows moisture to get in- and condensation to form which doesnt dissipate too quickly- which leads to corrosion at the terminals. Dab of dielectric around the edge of the cap, and where the wires lead in may help.

Im not sure there is a solution to making that area water tight with out using rtv to seal the cap. Cleaning the screws and terminals and then packing the top of the screws and terminals with dielectric as you have done should do a decent job of mitigating the chance for corrosion to reoccur.
I was writing about the reservoir cap, sorry!

The "boot" covering wire/screws/nuts is a different story.

What I did is replace screws/nuts, then pack dielectric grease around wires/nuts/screws and punched a hole in bottom of both boots.
 

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