I wonder if the motor bearings or bushings are bad. My 96 saturns ABS pump would squeal when it was below freezing.


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You can get the hydraulic seal kit form the dealer for $50 or so. Also you can rebuild the booster pump. The failure is the contact points on the armature (motor), and a shop in CA is rebuilding these. They also have rebuilt units.

Yes, when you get the dash lights and an alarm, you are there. I think you still have about 10 full brake paddle strokes to stop the truck after the alarm sound. Imagine it failing on a 6000 lb Cruiser...

bit of a better price on amayama. Still pretty expensive, but reliable source for part (from experience)

https://www.amayama.com/en/part/toyota/4702535010

I was lucky in that my brakes never totally failed. Every morning for 7 days the noise began screaming in the morning during cold starts. After truck warmed up it was quiet. Most days the truck was normal after the morning scream. Then one morning the dash lights and alarm tripped. Then every other day lights and alarm would trip. Noise gradually got louder and continued for a longer duration. I'd start it and let it get good and hot for 30 minutes before attempting to move it. The cacophony of noise coming from my garage had all my neighbors staring and giving me worried looks. It reminded me of when I used to smoke cigarettes, every morning I'd wake up coughing and hacking for 10 minutes but after I'd be ok for the day. Girlfriend thought I was dying, but after I got it out I was fine.
I needed the truck for work so I figured out to just get it hot and then unplug the battery for 2 minutes then restart. Doing that made the truck "forget" about the problem until the next cold start.
I do not recommend this as a real solution but it did work for me for several days. Brakes continued to work properly, though I kept a lot of distance from vehicles in front of me and my hand on the E-brake when driving as a last resort in case of total brake failure.
I'm thinking it's a bearing in the pump motor that performs better when hot. The failure symptoms usually only appeared during cold starts.

I have an '01 and I have always wondered how much it would cost to replace the master cylinder whenever I was doing work under the hood. I knew it wouldn't be cheap just the sheer complexity of its design but I would never have guessed it would be $3K.

I'm trying to wrap my head around that price, it's just so outlandish.

My truck has 242K and is due for a rear axle seal repair, power steering rack replacement and a fuel pump replacement. All of which are very expensive repairs as you all probably already know. I hope and pray this MC develops no issues because I just can't afford another repair at this point.

Thank you for sharing this information, Mutant.

I'm happy to help. This forum has helped me out a lot. Just want to return the favor.

I have another good condition Master Assembly for sale if anyone is interested. I bought a 2nd used unit as a backup because I needed my truck running ASAP. PM me if you would like to buy the other good assembly. 20lbs shipped from 79707. Paypal. $420 plus shipping. Good used unit. It is the entire assembly together.

I can also sell the bad Master Assembly if anyone wants particular parts off of it or wants to rebuild it. PM me.

My 00 is the same mileage... So all that's what I have to look forward to... Not fun! I'm also due for timing belt/water pump pretty soon as it was last replaced at 165K.

Did the repair go well?

I'm glad you brought this up, I had no idea this was a thing.

Mechanic said it was fine other than the time consuming process of bleeding the master unit. Bleed...wait an hour.....bleed....wait an hour....bleed...wait...bleed.
Truck behaves normally now but brake pedal is spongy. Probably needs lines bled after the swap.

That's odd, I just did the tundra brake upgrade on both of my 3rd gen and BOTH have spongy brakes even after bleeding all 4 wheels several times. I wonder if it has something to do with the MC.

It is easy to bleed these systems. No need to wait for hours.

Even after replacing the master pump, you still need to bleed all 4 wheels.

Turn the ignition key to "ON" position and bleed as you normally would. Be careful not to keep the ignition at ON position for prolong periods as this can heat up the ignition coil packs.
Have someone to press and hold the brakes. I got my daughter to do the job. The motor runs and pretty much pushes out the fluid. Be ready to catch all that.

While this part could be expensive; from reading here for several years I've seen little to zero mention of it as a "fatal flaw" much less just another problem. Really rare.

There are several other components that could cost thousands at a stealer like the engine, trans, rear end, a/c, front end, and on and on so this one item doesn't qualify IMOH as a "fatal flaw" just cuz of the cost.

A "fatal flaw" is developing sludge in an engine that is otherwise well maintened like the 2.0 4 cylinder and the 3.0 6 cylinder toyo made for many years in the 90s.

Luck to all....

https://www.ebay.com/p/?iid=28232538...pItem=1&chn=ps

Not so fatal merely a flesh wound.

the tundra calipers are larger, yes? then, yes if you don't also upsize the MC, you will have a soft pedal.

This is not the case with mine.. I have an 02 with larger Tundra brakes and my pedal feels great with no MC up size.